diff --git a/docs/model.md b/docs/model.md
index 7b8578c..379c6de 100644
--- a/docs/model.md
+++ b/docs/model.md
@@ -46,8 +46,8 @@ This page provides comprehensive information about the structure and components
         measurement(Measurement) --> measurementdata(MeasurementData)
         measurement(Measurement) --> unitdefinition(UnitDefinition)
         measurementdata(MeasurementData) --> unitdefinition(UnitDefinition)
-        measurementdata(MeasurementData) --> unitdefinition(UnitDefinition)
         measurementdata(MeasurementData) --> datatypes(DataTypes)
+        measurementdata(MeasurementData) --> unitdefinition(UnitDefinition)
         unitdefinition(UnitDefinition) --> baseunit(BaseUnit)
         baseunit(BaseUnit) --> unittype(UnitType)
 
@@ -73,8 +73,8 @@ This page provides comprehensive information about the structure and components
 
 
 ## Ontologies
-- [schema](https://schema.org/)
 - [OBO](http://purl.obolibrary.org/obo/)
+- [schema](https://schema.org/)
 
 
 ## Types
@@ -525,11 +525,6 @@ __data_unit__* [`UnitDefinition`](#unitdefinition)
 - SI unit of the data that was measured.
 
 
-__time_unit__* [`UnitDefinition`](#unitdefinition)
-
-- Time unit of the replicate.
-
-
 __data_type__* [`DataTypes`](#datatypes)
 
 - Type of data that was measured (e.g. concentration)
@@ -540,16 +535,21 @@ __prepared__ `float`
 - Amount of the reactant before the measurement. This field should be used for specifying the prepared amount of a species in the reaction mix. Not to be confused with
 
 
-__data__* `list[float]`
+__data__ `list[float]`
 
 - Data that was measured.
 
 
-__time__* `list[float]`
+__time__ `list[float]`
 
 - Time steps of the replicate.
 
 
+__time_unit__ [`UnitDefinition`](#unitdefinition)
+
+- Time unit of the replicate.
+
+
 __is_simulated__* `boolean`
 
 - Whether or not the data has been generated by simulation.
diff --git a/python/pyenzyme/dataclass_models.py b/python/pyenzyme/dataclass_models.py
index fbfbf5d..fa594ae 100644
--- a/python/pyenzyme/dataclass_models.py
+++ b/python/pyenzyme/dataclass_models.py
@@ -14,12 +14,8 @@
 class EnzymeMLDocument:
     name: str
     references: List[str] = field(default_factory=list)
-    created: Optional[str] = field(
-        default=None, metadata=config(exclude=lambda x: x is None)
-    )
-    modified: Optional[str] = field(
-        default=None, metadata=config(exclude=lambda x: x is None)
-    )
+    created: Optional[str] = field(default=None, metadata=config(exclude=lambda x: x is None))
+    modified: Optional[str] = field(default=None, metadata=config(exclude=lambda x: x is None))
     creators: List[Creator] = field(default_factory=list)
     vessels: List[Vessel] = field(default_factory=list)
     proteins: List[Protein] = field(default_factory=list)
@@ -33,20 +29,20 @@ class EnzymeMLDocument:
     # JSON-LD fields
     id: str = field(
         metadata=config(field_name="@id"),
-        default_factory=lambda: "enzml:EnzymeMLDocument/" + str(uuid4()),
+        default_factory=lambda: "enzml:EnzymeMLDocument/" + str(uuid4())
     )
     __type__: list[str] = field(
         metadata=config(field_name="@type"),
-        default_factory=lambda: [
+        default_factory = lambda: [
             "enzml:EnzymeMLDocument",
         ],
     )
     __context__: dict[str, str | dict] = field(
         metadata=config(field_name="@context"),
-        default_factory=lambda: {
+        default_factory = lambda: {
             "enzml": "http://www.enzymeml.org/v2/",
-            "schema": "https://schema.org/",
             "OBO": "http://purl.obolibrary.org/obo/",
+            "schema": "https://schema.org/",
             "name": "schema:title",
             "references": {
                 "@id": "schema:citation",
@@ -55,9 +51,10 @@ class EnzymeMLDocument:
             "created": "schema:dateCreated",
             "modified": "schema:dateModified",
             "creators": "schema:creator",
-        },
+        }
     )
 
+
     def add_to_creators(
         self,
         given_name: str,
@@ -65,22 +62,29 @@ def add_to_creators(
         mail: str,
         **kwargs,
     ):
-        params = {"given_name": given_name, "family_name": family_name, "mail": mail}
+        params = {
+            "given_name": given_name,
+            "family_name": family_name,
+            "mail": mail
+        }
 
         if "id" in kwargs:
             params["id"] = kwargs["id"]
 
-        self.creators.append(Creator(**params))
+        self.creators.append(
+            Creator(**params)
+        )
 
         return self.creators[-1]
 
+
     def add_to_vessels(
         self,
         id: str,
         name: str,
         volume: float,
         unit: UnitDefinition,
-        constant: bool = True,
+        constant: bool= True,
         **kwargs,
     ):
         params = {
@@ -88,27 +92,30 @@ def add_to_vessels(
             "name": name,
             "volume": volume,
             "unit": unit,
-            "constant": constant,
+            "constant": constant
         }
 
         if "id" in kwargs:
             params["id"] = kwargs["id"]
 
-        self.vessels.append(Vessel(**params))
+        self.vessels.append(
+            Vessel(**params)
+        )
 
         return self.vessels[-1]
 
+
     def add_to_proteins(
         self,
         id: str,
         name: str,
-        constant: bool = False,
-        sequence: Optional[str] = None,
-        vessel_id: Optional[str] = None,
-        ecnumber: Optional[str] = None,
-        organism: Optional[str] = None,
-        organism_tax_id: Optional[str] = None,
-        references: list[str] = [],
+        constant: bool= False,
+        sequence: Optional[str]= None,
+        vessel_id: Optional[str]= None,
+        ecnumber: Optional[str]= None,
+        organism: Optional[str]= None,
+        organism_tax_id: Optional[str]= None,
+        references: list[str]= [],
         **kwargs,
     ):
         params = {
@@ -120,48 +127,54 @@ def add_to_proteins(
             "ecnumber": ecnumber,
             "organism": organism,
             "organism_tax_id": organism_tax_id,
-            "references": references,
+            "references": references
         }
 
         if "id" in kwargs:
             params["id"] = kwargs["id"]
 
-        self.proteins.append(Protein(**params))
+        self.proteins.append(
+            Protein(**params)
+        )
 
         return self.proteins[-1]
 
+
     def add_to_complexes(
         self,
         id: str,
         name: str,
-        constant: bool = False,
-        participants: list[str] = [],
+        constant: bool= False,
+        participants: list[str]= [],
         **kwargs,
     ):
         params = {
             "id": id,
             "name": name,
             "constant": constant,
-            "participants": participants,
+            "participants": participants
         }
 
         if "id" in kwargs:
             params["id"] = kwargs["id"]
 
-        self.complexes.append(Complex(**params))
+        self.complexes.append(
+            Complex(**params)
+        )
 
         return self.complexes[-1]
 
+
     def add_to_small_molecules(
         self,
         id: str,
         name: str,
-        constant: bool = False,
-        vessel_id: Optional[str] = None,
-        canonical_smiles: Optional[str] = None,
-        inchi: Optional[str] = None,
-        inchikey: Optional[str] = None,
-        references: list[str] = [],
+        constant: bool= False,
+        vessel_id: Optional[str]= None,
+        canonical_smiles: Optional[str]= None,
+        inchi: Optional[str]= None,
+        inchikey: Optional[str]= None,
+        references: list[str]= [],
         **kwargs,
     ):
         params = {
@@ -172,24 +185,27 @@ def add_to_small_molecules(
             "canonical_smiles": canonical_smiles,
             "inchi": inchi,
             "inchikey": inchikey,
-            "references": references,
+            "references": references
         }
 
         if "id" in kwargs:
             params["id"] = kwargs["id"]
 
-        self.small_molecules.append(SmallMolecule(**params))
+        self.small_molecules.append(
+            SmallMolecule(**params)
+        )
 
         return self.small_molecules[-1]
 
+
     def add_to_reactions(
         self,
         id: str,
         name: str,
-        reversible: bool = False,
-        kinetic_law: Optional[Equation] = None,
-        species: list[ReactionElement] = [],
-        modifiers: list[str] = [],
+        reversible: bool= False,
+        kinetic_law: Optional[Equation]= None,
+        species: list[ReactionElement]= [],
+        modifiers: list[str]= [],
         **kwargs,
     ):
         params = {
@@ -198,25 +214,28 @@ def add_to_reactions(
             "reversible": reversible,
             "kinetic_law": kinetic_law,
             "species": species,
-            "modifiers": modifiers,
+            "modifiers": modifiers
         }
 
         if "id" in kwargs:
             params["id"] = kwargs["id"]
 
-        self.reactions.append(Reaction(**params))
+        self.reactions.append(
+            Reaction(**params)
+        )
 
         return self.reactions[-1]
 
+
     def add_to_measurements(
         self,
         id: str,
         name: str,
-        species_data: list[MeasurementData] = [],
-        group_id: Optional[str] = None,
-        ph: Optional[float] = None,
-        temperature: Optional[float] = None,
-        temperature_unit: Optional[UnitDefinition] = None,
+        species_data: list[MeasurementData]= [],
+        group_id: Optional[str]= None,
+        ph: Optional[float]= None,
+        temperature: Optional[float]= None,
+        temperature_unit: Optional[UnitDefinition]= None,
         **kwargs,
     ):
         params = {
@@ -226,50 +245,56 @@ def add_to_measurements(
             "group_id": group_id,
             "ph": ph,
             "temperature": temperature,
-            "temperature_unit": temperature_unit,
+            "temperature_unit": temperature_unit
         }
 
         if "id" in kwargs:
             params["id"] = kwargs["id"]
 
-        self.measurements.append(Measurement(**params))
+        self.measurements.append(
+            Measurement(**params)
+        )
 
         return self.measurements[-1]
 
+
     def add_to_equations(
         self,
         equation: str,
         equation_type: EquationType,
-        species_id: Optional[str] = None,
-        variables: list[Variable] = [],
+        species_id: Optional[str]= None,
+        variables: list[Variable]= [],
         **kwargs,
     ):
         params = {
             "equation": equation,
             "equation_type": equation_type,
             "species_id": species_id,
-            "variables": variables,
+            "variables": variables
         }
 
         if "id" in kwargs:
             params["id"] = kwargs["id"]
 
-        self.equations.append(Equation(**params))
+        self.equations.append(
+            Equation(**params)
+        )
 
         return self.equations[-1]
 
+
     def add_to_parameters(
         self,
         id: str,
         name: str,
         symbol: str,
-        value: Optional[float] = None,
-        unit: Optional[UnitDefinition] = None,
-        initial_value: Optional[float] = None,
-        upper: Optional[float] = None,
-        lower: Optional[float] = None,
-        stderr: Optional[float] = None,
-        constant: Optional[bool] = True,
+        value: Optional[float]= None,
+        unit: Optional[UnitDefinition]= None,
+        initial_value: Optional[float]= None,
+        upper: Optional[float]= None,
+        lower: Optional[float]= None,
+        stderr: Optional[float]= None,
+        constant: Optional[bool]= True,
         **kwargs,
     ):
         params = {
@@ -282,17 +307,18 @@ def add_to_parameters(
             "upper": upper,
             "lower": lower,
             "stderr": stderr,
-            "constant": constant,
+            "constant": constant
         }
 
         if "id" in kwargs:
             params["id"] = kwargs["id"]
 
-        self.parameters.append(Parameter(**params))
+        self.parameters.append(
+            Parameter(**params)
+        )
 
         return self.parameters[-1]
 
-
 @dataclass_json
 @dataclass
 class Creator:
@@ -303,22 +329,24 @@ class Creator:
     # JSON-LD fields
     id: str = field(
         metadata=config(field_name="@id"),
-        default_factory=lambda: "enzml:Creator/" + str(uuid4()),
+        default_factory=lambda: "enzml:Creator/" + str(uuid4())
     )
     __type__: list[str] = field(
         metadata=config(field_name="@type"),
-        default_factory=lambda: ["enzml:Creator", "schema:person"],
+        default_factory = lambda: [
+            "enzml:Creator","schema:person"
+        ],
     )
     __context__: dict[str, str | dict] = field(
         metadata=config(field_name="@context"),
-        default_factory=lambda: {
+        default_factory = lambda: {
             "enzml": "http://www.enzymeml.org/v2/",
-            "schema": "https://schema.org/",
             "OBO": "http://purl.obolibrary.org/obo/",
+            "schema": "https://schema.org/",
             "given_name": "schema:givenName",
             "family_name": "schema:familyName",
             "mail": "schema:email",
-        },
+        }
     )
 
 
@@ -333,25 +361,27 @@ class Vessel:
     # JSON-LD fields
     id: str = field(
         metadata=config(field_name="@id"),
-        default_factory=lambda: "enzml:Vessel/" + str(uuid4()),
+        default_factory=lambda: "enzml:Vessel/" + str(uuid4())
     )
     __type__: list[str] = field(
         metadata=config(field_name="@type"),
-        default_factory=lambda: ["enzml:Vessel", "OBO:OBI_0400081"],
+        default_factory = lambda: [
+            "enzml:Vessel","OBO:OBI_0400081"
+        ],
     )
     __context__: dict[str, str | dict] = field(
         metadata=config(field_name="@context"),
-        default_factory=lambda: {
+        default_factory = lambda: {
             "enzml": "http://www.enzymeml.org/v2/",
-            "schema": "https://schema.org/",
             "OBO": "http://purl.obolibrary.org/obo/",
+            "schema": "https://schema.org/",
             "id": {
                 "@id": "schema:identifier",
                 "@type": "@id",
             },
             "name": "schema:name",
             "volume": "OBO:OBI_0002139",
-        },
+        }
     )
 
 
@@ -360,38 +390,30 @@ class Vessel:
 class Protein:
     name: str
     constant: bool = False
-    sequence: Optional[str] = field(
-        default=None, metadata=config(exclude=lambda x: x is None)
-    )
-    vessel_id: Optional[str] = field(
-        default=None, metadata=config(exclude=lambda x: x is None)
-    )
-    ecnumber: Optional[str] = field(
-        default=None, metadata=config(exclude=lambda x: x is None)
-    )
-    organism: Optional[str] = field(
-        default=None, metadata=config(exclude=lambda x: x is None)
-    )
-    organism_tax_id: Optional[str] = field(
-        default=None, metadata=config(exclude=lambda x: x is None)
-    )
+    sequence: Optional[str] = field(default=None, metadata=config(exclude=lambda x: x is None))
+    vessel_id: Optional[str] = field(default=None, metadata=config(exclude=lambda x: x is None))
+    ecnumber: Optional[str] = field(default=None, metadata=config(exclude=lambda x: x is None))
+    organism: Optional[str] = field(default=None, metadata=config(exclude=lambda x: x is None))
+    organism_tax_id: Optional[str] = field(default=None, metadata=config(exclude=lambda x: x is None))
     references: List[str] = field(default_factory=list)
 
     # JSON-LD fields
     id: str = field(
         metadata=config(field_name="@id"),
-        default_factory=lambda: "enzml:Protein/" + str(uuid4()),
+        default_factory=lambda: "enzml:Protein/" + str(uuid4())
     )
     __type__: list[str] = field(
         metadata=config(field_name="@type"),
-        default_factory=lambda: ["enzml:Protein", "schema:Protein"],
+        default_factory = lambda: [
+            "enzml:Protein","schema:Protein"
+        ],
     )
     __context__: dict[str, str | dict] = field(
         metadata=config(field_name="@context"),
-        default_factory=lambda: {
+        default_factory = lambda: {
             "enzml": "http://www.enzymeml.org/v2/",
-            "schema": "https://schema.org/",
             "OBO": "http://purl.obolibrary.org/obo/",
+            "schema": "https://schema.org/",
             "id": {
                 "@type": "@id",
             },
@@ -409,7 +431,7 @@ class Protein:
                 "@id": "schema:citation",
                 "@type": "@id",
             },
-        },
+        }
     )
 
 
@@ -423,20 +445,20 @@ class Complex:
     # JSON-LD fields
     id: str = field(
         metadata=config(field_name="@id"),
-        default_factory=lambda: "enzml:Complex/" + str(uuid4()),
+        default_factory=lambda: "enzml:Complex/" + str(uuid4())
     )
     __type__: list[str] = field(
         metadata=config(field_name="@type"),
-        default_factory=lambda: [
+        default_factory = lambda: [
             "enzml:Complex",
         ],
     )
     __context__: dict[str, str | dict] = field(
         metadata=config(field_name="@context"),
-        default_factory=lambda: {
+        default_factory = lambda: {
             "enzml": "http://www.enzymeml.org/v2/",
-            "schema": "https://schema.org/",
             "OBO": "http://purl.obolibrary.org/obo/",
+            "schema": "https://schema.org/",
             "id": {
                 "@id": "schema:identifier",
                 "@type": "@id",
@@ -445,7 +467,7 @@ class Complex:
             "participants": {
                 "@type": "@id",
             },
-        },
+        }
     )
 
 
@@ -454,37 +476,29 @@ class Complex:
 class SmallMolecule:
     name: str
     constant: bool = False
-    vessel_id: Optional[str] = field(
-        default=None, metadata=config(exclude=lambda x: x is None)
-    )
-    canonical_smiles: Optional[str] = field(
-        default=None, metadata=config(exclude=lambda x: x is None)
-    )
-    inchi: Optional[str] = field(
-        default=None, metadata=config(exclude=lambda x: x is None)
-    )
-    inchikey: Optional[str] = field(
-        default=None, metadata=config(exclude=lambda x: x is None)
-    )
+    vessel_id: Optional[str] = field(default=None, metadata=config(exclude=lambda x: x is None))
+    canonical_smiles: Optional[str] = field(default=None, metadata=config(exclude=lambda x: x is None))
+    inchi: Optional[str] = field(default=None, metadata=config(exclude=lambda x: x is None))
+    inchikey: Optional[str] = field(default=None, metadata=config(exclude=lambda x: x is None))
     references: List[str] = field(default_factory=list)
 
     # JSON-LD fields
     id: str = field(
         metadata=config(field_name="@id"),
-        default_factory=lambda: "enzml:SmallMolecule/" + str(uuid4()),
+        default_factory=lambda: "enzml:SmallMolecule/" + str(uuid4())
     )
     __type__: list[str] = field(
         metadata=config(field_name="@type"),
-        default_factory=lambda: [
+        default_factory = lambda: [
             "enzml:SmallMolecule",
         ],
     )
     __context__: dict[str, str | dict] = field(
         metadata=config(field_name="@context"),
-        default_factory=lambda: {
+        default_factory = lambda: {
             "enzml": "http://www.enzymeml.org/v2/",
-            "schema": "https://schema.org/",
             "OBO": "http://purl.obolibrary.org/obo/",
+            "schema": "https://schema.org/",
             "id": {
                 "@id": "schema:identifier",
                 "@type": "@id",
@@ -498,7 +512,7 @@ class SmallMolecule:
                 "@id": "schema:citation",
                 "@type": "@id",
             },
-        },
+        }
     )
 
 
@@ -507,29 +521,27 @@ class SmallMolecule:
 class Reaction:
     name: str
     reversible: bool = False
-    kinetic_law: Optional[Equation] = field(
-        default=None, metadata=config(exclude=lambda x: x is None)
-    )
+    kinetic_law: Optional[Equation] = field(default=None, metadata=config(exclude=lambda x: x is None))
     species: List[ReactionElement] = field(default_factory=list)
     modifiers: List[str] = field(default_factory=list)
 
     # JSON-LD fields
     id: str = field(
         metadata=config(field_name="@id"),
-        default_factory=lambda: "enzml:Reaction/" + str(uuid4()),
+        default_factory=lambda: "enzml:Reaction/" + str(uuid4())
     )
     __type__: list[str] = field(
         metadata=config(field_name="@type"),
-        default_factory=lambda: [
+        default_factory = lambda: [
             "enzml:Reaction",
         ],
     )
     __context__: dict[str, str | dict] = field(
         metadata=config(field_name="@context"),
-        default_factory=lambda: {
+        default_factory = lambda: {
             "enzml": "http://www.enzymeml.org/v2/",
-            "schema": "https://schema.org/",
             "OBO": "http://purl.obolibrary.org/obo/",
+            "schema": "https://schema.org/",
             "id": {
                 "@id": "schema:identifier",
                 "@type": "@id",
@@ -537,21 +549,27 @@ class Reaction:
             "modifiers": {
                 "@type": "@id",
             },
-        },
+        }
     )
 
+
     def add_to_species(
         self,
         species_id: str,
         stoichiometry: float,
         **kwargs,
     ):
-        params = {"species_id": species_id, "stoichiometry": stoichiometry}
+        params = {
+            "species_id": species_id,
+            "stoichiometry": stoichiometry
+        }
 
         if "id" in kwargs:
             params["id"] = kwargs["id"]
 
-        self.species.append(ReactionElement(**params))
+        self.species.append(
+            ReactionElement(**params)
+        )
 
         return self.species[-1]
 
@@ -565,24 +583,24 @@ class ReactionElement:
     # JSON-LD fields
     id: str = field(
         metadata=config(field_name="@id"),
-        default_factory=lambda: "enzml:ReactionElement/" + str(uuid4()),
+        default_factory=lambda: "enzml:ReactionElement/" + str(uuid4())
     )
     __type__: list[str] = field(
         metadata=config(field_name="@type"),
-        default_factory=lambda: [
+        default_factory = lambda: [
             "enzml:ReactionElement",
         ],
     )
     __context__: dict[str, str | dict] = field(
         metadata=config(field_name="@context"),
-        default_factory=lambda: {
+        default_factory = lambda: {
             "enzml": "http://www.enzymeml.org/v2/",
-            "schema": "https://schema.org/",
             "OBO": "http://purl.obolibrary.org/obo/",
+            "schema": "https://schema.org/",
             "species_id": {
                 "@type": "@id",
             },
-        },
+        }
     )
 
 
@@ -591,34 +609,33 @@ class ReactionElement:
 class Equation:
     equation: str
     equation_type: EquationType
-    species_id: Optional[str] = field(
-        default=None, metadata=config(exclude=lambda x: x is None)
-    )
+    species_id: Optional[str] = field(default=None, metadata=config(exclude=lambda x: x is None))
     variables: List[Variable] = field(default_factory=list)
 
     # JSON-LD fields
     id: str = field(
         metadata=config(field_name="@id"),
-        default_factory=lambda: "enzml:Equation/" + str(uuid4()),
+        default_factory=lambda: "enzml:Equation/" + str(uuid4())
     )
     __type__: list[str] = field(
         metadata=config(field_name="@type"),
-        default_factory=lambda: [
+        default_factory = lambda: [
             "enzml:Equation",
         ],
     )
     __context__: dict[str, str | dict] = field(
         metadata=config(field_name="@context"),
-        default_factory=lambda: {
+        default_factory = lambda: {
             "enzml": "http://www.enzymeml.org/v2/",
-            "schema": "https://schema.org/",
             "OBO": "http://purl.obolibrary.org/obo/",
+            "schema": "https://schema.org/",
             "species_id": {
                 "@type": "@id",
             },
-        },
+        }
     )
 
+
     def add_to_variables(
         self,
         id: str,
@@ -626,16 +643,21 @@ def add_to_variables(
         symbol: str,
         **kwargs,
     ):
-        params = {"id": id, "name": name, "symbol": symbol}
+        params = {
+            "id": id,
+            "name": name,
+            "symbol": symbol
+        }
 
         if "id" in kwargs:
             params["id"] = kwargs["id"]
 
-        self.variables.append(Variable(**params))
+        self.variables.append(
+            Variable(**params)
+        )
 
         return self.variables[-1]
 
-
 @dataclass_json
 @dataclass
 class Variable:
@@ -645,22 +667,22 @@ class Variable:
     # JSON-LD fields
     id: str = field(
         metadata=config(field_name="@id"),
-        default_factory=lambda: "enzml:Variable/" + str(uuid4()),
+        default_factory=lambda: "enzml:Variable/" + str(uuid4())
     )
     __type__: list[str] = field(
         metadata=config(field_name="@type"),
-        default_factory=lambda: [
+        default_factory = lambda: [
             "enzml:Variable",
         ],
     )
     __context__: dict[str, str | dict] = field(
         metadata=config(field_name="@context"),
-        default_factory=lambda: {
+        default_factory = lambda: {
             "enzml": "http://www.enzymeml.org/v2/",
-            "schema": "https://schema.org/",
             "OBO": "http://purl.obolibrary.org/obo/",
+            "schema": "https://schema.org/",
             "id": "schema:identifier",
-        },
+        }
     )
 
 
@@ -669,48 +691,36 @@ class Variable:
 class Parameter:
     name: str
     symbol: str
-    value: Optional[float] = field(
-        default=None, metadata=config(exclude=lambda x: x is None)
-    )
-    unit: Optional[UnitDefinition] = field(
-        default=None, metadata=config(exclude=lambda x: x is None)
-    )
-    initial_value: Optional[float] = field(
-        default=None, metadata=config(exclude=lambda x: x is None)
-    )
-    upper: Optional[float] = field(
-        default=None, metadata=config(exclude=lambda x: x is None)
-    )
-    lower: Optional[float] = field(
-        default=None, metadata=config(exclude=lambda x: x is None)
-    )
-    stderr: Optional[float] = field(
-        default=None, metadata=config(exclude=lambda x: x is None)
-    )
+    value: Optional[float] = field(default=None, metadata=config(exclude=lambda x: x is None))
+    unit: Optional[UnitDefinition] = field(default=None, metadata=config(exclude=lambda x: x is None))
+    initial_value: Optional[float] = field(default=None, metadata=config(exclude=lambda x: x is None))
+    upper: Optional[float] = field(default=None, metadata=config(exclude=lambda x: x is None))
+    lower: Optional[float] = field(default=None, metadata=config(exclude=lambda x: x is None))
+    stderr: Optional[float] = field(default=None, metadata=config(exclude=lambda x: x is None))
     constant: bool = True
 
     # JSON-LD fields
     id: str = field(
         metadata=config(field_name="@id"),
-        default_factory=lambda: "enzml:Parameter/" + str(uuid4()),
+        default_factory=lambda: "enzml:Parameter/" + str(uuid4())
     )
     __type__: list[str] = field(
         metadata=config(field_name="@type"),
-        default_factory=lambda: [
+        default_factory = lambda: [
             "enzml:Parameter",
         ],
     )
     __context__: dict[str, str | dict] = field(
         metadata=config(field_name="@context"),
-        default_factory=lambda: {
+        default_factory = lambda: {
             "enzml": "http://www.enzymeml.org/v2/",
-            "schema": "https://schema.org/",
             "OBO": "http://purl.obolibrary.org/obo/",
+            "schema": "https://schema.org/",
             "id": {
                 "@id": "schema:identifier",
                 "@type": "@id",
             },
-        },
+        }
     )
 
 
@@ -719,36 +729,28 @@ class Parameter:
 class Measurement:
     name: str
     species_data: List[MeasurementData] = field(default_factory=list)
-    group_id: Optional[str] = field(
-        default=None, metadata=config(exclude=lambda x: x is None)
-    )
-    ph: Optional[float] = field(
-        default=None, metadata=config(exclude=lambda x: x is None)
-    )
-    temperature: Optional[float] = field(
-        default=None, metadata=config(exclude=lambda x: x is None)
-    )
-    temperature_unit: Optional[UnitDefinition] = field(
-        default=None, metadata=config(exclude=lambda x: x is None)
-    )
+    group_id: Optional[str] = field(default=None, metadata=config(exclude=lambda x: x is None))
+    ph: Optional[float] = field(default=None, metadata=config(exclude=lambda x: x is None))
+    temperature: Optional[float] = field(default=None, metadata=config(exclude=lambda x: x is None))
+    temperature_unit: Optional[UnitDefinition] = field(default=None, metadata=config(exclude=lambda x: x is None))
 
     # JSON-LD fields
     id: str = field(
         metadata=config(field_name="@id"),
-        default_factory=lambda: "enzml:Measurement/" + str(uuid4()),
+        default_factory=lambda: "enzml:Measurement/" + str(uuid4())
     )
     __type__: list[str] = field(
         metadata=config(field_name="@type"),
-        default_factory=lambda: [
+        default_factory = lambda: [
             "enzml:Measurement",
         ],
     )
     __context__: dict[str, str | dict] = field(
         metadata=config(field_name="@context"),
-        default_factory=lambda: {
+        default_factory = lambda: {
             "enzml": "http://www.enzymeml.org/v2/",
-            "schema": "https://schema.org/",
             "OBO": "http://purl.obolibrary.org/obo/",
+            "schema": "https://schema.org/",
             "id": {
                 "@id": "schema:identifier",
                 "@type": "@id",
@@ -756,38 +758,41 @@ class Measurement:
             "group_id": {
                 "@type": "@id",
             },
-        },
+        }
     )
 
+
     def add_to_species_data(
         self,
         species_id: str,
         initial: float,
         data_unit: UnitDefinition,
-        time_unit: UnitDefinition,
         data_type: DataTypes,
-        prepared: Optional[float] = None,
-        data: list[float] = [],
-        time: list[float] = [],
-        is_simulated: bool = False,
+        prepared: Optional[float]= None,
+        data: list[float]= [],
+        time: list[float]= [],
+        time_unit: Optional[UnitDefinition]= None,
+        is_simulated: bool= False,
         **kwargs,
     ):
         params = {
             "species_id": species_id,
             "initial": initial,
             "data_unit": data_unit,
-            "time_unit": time_unit,
             "data_type": data_type,
             "prepared": prepared,
             "data": data,
             "time": time,
-            "is_simulated": is_simulated,
+            "time_unit": time_unit,
+            "is_simulated": is_simulated
         }
 
         if "id" in kwargs:
             params["id"] = kwargs["id"]
 
-        self.species_data.append(MeasurementData(**params))
+        self.species_data.append(
+            MeasurementData(**params)
+        )
 
         return self.species_data[-1]
 
@@ -798,120 +803,114 @@ class MeasurementData:
     species_id: str
     initial: float
     data_unit: UnitDefinition
-    time_unit: UnitDefinition
     data_type: DataTypes
-    prepared: Optional[float] = field(
-        default=None, metadata=config(exclude=lambda x: x is None)
-    )
+    prepared: Optional[float] = field(default=None, metadata=config(exclude=lambda x: x is None))
     data: List[float] = field(default_factory=list)
     time: List[float] = field(default_factory=list)
+    time_unit: Optional[UnitDefinition] = field(default=None, metadata=config(exclude=lambda x: x is None))
     is_simulated: bool = False
 
     # JSON-LD fields
     id: str = field(
         metadata=config(field_name="@id"),
-        default_factory=lambda: "enzml:MeasurementData/" + str(uuid4()),
+        default_factory=lambda: "enzml:MeasurementData/" + str(uuid4())
     )
     __type__: list[str] = field(
         metadata=config(field_name="@type"),
-        default_factory=lambda: [
+        default_factory = lambda: [
             "enzml:MeasurementData",
         ],
     )
     __context__: dict[str, str | dict] = field(
         metadata=config(field_name="@context"),
-        default_factory=lambda: {
+        default_factory = lambda: {
             "enzml": "http://www.enzymeml.org/v2/",
-            "schema": "https://schema.org/",
             "OBO": "http://purl.obolibrary.org/obo/",
+            "schema": "https://schema.org/",
             "species_id": {
                 "@type": "@id",
             },
-        },
+        }
     )
 
 
 @dataclass_json
 @dataclass
 class UnitDefinition:
-    name: Optional[str] = field(
-        default=None, metadata=config(exclude=lambda x: x is None)
-    )
+    name: Optional[str] = field(default=None, metadata=config(exclude=lambda x: x is None))
     base_units: List[BaseUnit] = field(default_factory=list)
 
     # JSON-LD fields
     id: str = field(
         metadata=config(field_name="@id"),
-        default_factory=lambda: "enzml:UnitDefinition/" + str(uuid4()),
+        default_factory=lambda: "enzml:UnitDefinition/" + str(uuid4())
     )
     __type__: list[str] = field(
         metadata=config(field_name="@type"),
-        default_factory=lambda: [
+        default_factory = lambda: [
             "enzml:UnitDefinition",
         ],
     )
     __context__: dict[str, str | dict] = field(
         metadata=config(field_name="@context"),
-        default_factory=lambda: {
+        default_factory = lambda: {
             "enzml": "http://www.enzymeml.org/v2/",
-            "schema": "https://schema.org/",
             "OBO": "http://purl.obolibrary.org/obo/",
-        },
+            "schema": "https://schema.org/",
+        }
     )
 
+
     def add_to_base_units(
         self,
         kind: UnitType,
         exponent: int,
-        multiplier: Optional[float] = None,
-        scale: Optional[float] = None,
+        multiplier: Optional[float]= None,
+        scale: Optional[float]= None,
         **kwargs,
     ):
         params = {
             "kind": kind,
             "exponent": exponent,
             "multiplier": multiplier,
-            "scale": scale,
+            "scale": scale
         }
 
         if "id" in kwargs:
             params["id"] = kwargs["id"]
 
-        self.base_units.append(BaseUnit(**params))
+        self.base_units.append(
+            BaseUnit(**params)
+        )
 
         return self.base_units[-1]
 
-
 @dataclass_json
 @dataclass
 class BaseUnit:
     kind: UnitType
     exponent: int
-    multiplier: Optional[float] = field(
-        default=None, metadata=config(exclude=lambda x: x is None)
-    )
-    scale: Optional[float] = field(
-        default=None, metadata=config(exclude=lambda x: x is None)
-    )
+    multiplier: Optional[float] = field(default=None, metadata=config(exclude=lambda x: x is None))
+    scale: Optional[float] = field(default=None, metadata=config(exclude=lambda x: x is None))
 
     # JSON-LD fields
     id: str = field(
         metadata=config(field_name="@id"),
-        default_factory=lambda: "enzml:BaseUnit/" + str(uuid4()),
+        default_factory=lambda: "enzml:BaseUnit/" + str(uuid4())
     )
     __type__: list[str] = field(
         metadata=config(field_name="@type"),
-        default_factory=lambda: [
+        default_factory = lambda: [
             "enzml:BaseUnit",
         ],
     )
     __context__: dict[str, str | dict] = field(
         metadata=config(field_name="@context"),
-        default_factory=lambda: {
+        default_factory = lambda: {
             "enzml": "http://www.enzymeml.org/v2/",
-            "schema": "https://schema.org/",
             "OBO": "http://purl.obolibrary.org/obo/",
-        },
+            "schema": "https://schema.org/",
+        }
     )
 
 
@@ -921,7 +920,6 @@ class EquationType(Enum):
     ODE = "ode"
     RATE_LAW = "rateLaw"
 
-
 class DataTypes(Enum):
     ABSORBANCE = "http://purl.allotrope.org/ontologies/quality#AFQ_0000061"
     CONCENTRATION = "http://purl.obolibrary.org/obo/PATO_0000033"
@@ -930,7 +928,6 @@ class DataTypes(Enum):
     PEAK_AREA = "http://purl.allotrope.org/ontologies/result#AFR_0001073"
     TRANSMITTANCE = "http://purl.allotrope.org/ontologies/result#AFR_0002261"
 
-
 class UnitType(Enum):
     AMPERE = "ampere"
     AVOGADRO = "avogadro"
@@ -965,4 +962,4 @@ class UnitType(Enum):
     TESLA = "tesla"
     VOLT = "volt"
     WATT = "watt"
-    WEBER = "weber"
+    WEBER = "weber"
\ No newline at end of file
diff --git a/python/pyenzyme/pydantic_models.py b/python/pyenzyme/pydantic_models.py
index f5784ba..314e63b 100644
--- a/python/pyenzyme/pydantic_models.py
+++ b/python/pyenzyme/pydantic_models.py
@@ -1,11 +1,12 @@
 ## This is a generated file. Do not modify it manually!
 
 from __future__ import annotations
-from pydantic import BaseModel, Field, ConfigDict
-from typing import Optional, Generic, TypeVar
+
 from enum import Enum
+from typing import Generic, Optional, TypeVar
 from uuid import uuid4
-from datetime import date, datetime
+
+from pydantic import BaseModel, ConfigDict, Field
 
 # Filter Wrapper definition used to filter a list of objects
 # based on their attributes
@@ -105,8 +106,8 @@ class EnzymeMLDocument(BaseModel):
         serialization_alias="@context",
         default_factory=lambda: {
             "enzml": "http://www.enzymeml.org/v2/",
-            "schema": "https://schema.org/",
             "OBO": "http://purl.obolibrary.org/obo/",
+            "schema": "https://schema.org/",
             "name": "schema:title",
             "references": {
                 "@id": "schema:citation",
@@ -548,8 +549,8 @@ class Creator(BaseModel):
         serialization_alias="@context",
         default_factory=lambda: {
             "enzml": "http://www.enzymeml.org/v2/",
-            "schema": "https://schema.org/",
             "OBO": "http://purl.obolibrary.org/obo/",
+            "schema": "https://schema.org/",
             "given_name": "schema:givenName",
             "family_name": "schema:familyName",
             "mail": "schema:email",
@@ -646,8 +647,8 @@ class Vessel(BaseModel):
         serialization_alias="@context",
         default_factory=lambda: {
             "enzml": "http://www.enzymeml.org/v2/",
-            "schema": "https://schema.org/",
             "OBO": "http://purl.obolibrary.org/obo/",
+            "schema": "https://schema.org/",
             "id": {
                 "@id": "schema:identifier",
                 "@type": "@id",
@@ -751,8 +752,8 @@ class Protein(BaseModel):
         serialization_alias="@context",
         default_factory=lambda: {
             "enzml": "http://www.enzymeml.org/v2/",
-            "schema": "https://schema.org/",
             "OBO": "http://purl.obolibrary.org/obo/",
+            "schema": "https://schema.org/",
             "id": {
                 "@type": "@id",
             },
@@ -864,8 +865,8 @@ class Complex(BaseModel):
         serialization_alias="@context",
         default_factory=lambda: {
             "enzml": "http://www.enzymeml.org/v2/",
-            "schema": "https://schema.org/",
             "OBO": "http://purl.obolibrary.org/obo/",
+            "schema": "https://schema.org/",
             "id": {
                 "@id": "schema:identifier",
                 "@type": "@id",
@@ -972,8 +973,8 @@ class SmallMolecule(BaseModel):
         serialization_alias="@context",
         default_factory=lambda: {
             "enzml": "http://www.enzymeml.org/v2/",
-            "schema": "https://schema.org/",
             "OBO": "http://purl.obolibrary.org/obo/",
+            "schema": "https://schema.org/",
             "id": {
                 "@id": "schema:identifier",
                 "@type": "@id",
@@ -1083,8 +1084,8 @@ class Reaction(BaseModel):
         serialization_alias="@context",
         default_factory=lambda: {
             "enzml": "http://www.enzymeml.org/v2/",
-            "schema": "https://schema.org/",
             "OBO": "http://purl.obolibrary.org/obo/",
+            "schema": "https://schema.org/",
             "id": {
                 "@id": "schema:identifier",
                 "@type": "@id",
@@ -1211,8 +1212,8 @@ class ReactionElement(BaseModel):
         serialization_alias="@context",
         default_factory=lambda: {
             "enzml": "http://www.enzymeml.org/v2/",
-            "schema": "https://schema.org/",
             "OBO": "http://purl.obolibrary.org/obo/",
+            "schema": "https://schema.org/",
             "species_id": {
                 "@type": "@id",
             },
@@ -1310,8 +1311,8 @@ class Equation(BaseModel):
         serialization_alias="@context",
         default_factory=lambda: {
             "enzml": "http://www.enzymeml.org/v2/",
-            "schema": "https://schema.org/",
             "OBO": "http://purl.obolibrary.org/obo/",
+            "schema": "https://schema.org/",
             "species_id": {
                 "@type": "@id",
             },
@@ -1436,8 +1437,8 @@ class Variable(BaseModel):
         serialization_alias="@context",
         default_factory=lambda: {
             "enzml": "http://www.enzymeml.org/v2/",
-            "schema": "https://schema.org/",
             "OBO": "http://purl.obolibrary.org/obo/",
+            "schema": "https://schema.org/",
             "id": "schema:identifier",
         },
     )
@@ -1539,8 +1540,8 @@ class Parameter(BaseModel):
         serialization_alias="@context",
         default_factory=lambda: {
             "enzml": "http://www.enzymeml.org/v2/",
-            "schema": "https://schema.org/",
             "OBO": "http://purl.obolibrary.org/obo/",
+            "schema": "https://schema.org/",
             "id": {
                 "@id": "schema:identifier",
                 "@type": "@id",
@@ -1642,8 +1643,8 @@ class Measurement(BaseModel):
         serialization_alias="@context",
         default_factory=lambda: {
             "enzml": "http://www.enzymeml.org/v2/",
-            "schema": "https://schema.org/",
             "OBO": "http://purl.obolibrary.org/obo/",
+            "schema": "https://schema.org/",
             "id": {
                 "@id": "schema:identifier",
                 "@type": "@id",
@@ -1736,11 +1737,11 @@ def add_to_species_data(
         species_id: str,
         initial: float,
         data_unit: UnitDefinition,
-        time_unit: UnitDefinition,
         data_type: DataTypes,
         prepared: Optional[float] = None,
         data: list[float] = [],
         time: list[float] = [],
+        time_unit: Optional[UnitDefinition] = None,
         is_simulated: bool = False,
         **kwargs,
     ):
@@ -1748,11 +1749,11 @@ def add_to_species_data(
             "species_id": species_id,
             "initial": initial,
             "data_unit": data_unit,
-            "time_unit": time_unit,
             "data_type": data_type,
             "prepared": prepared,
             "data": data,
             "time": time,
+            "time_unit": time_unit,
             "is_simulated": is_simulated,
         }
 
@@ -1772,11 +1773,11 @@ class MeasurementData(BaseModel):
     species_id: str
     initial: float
     data_unit: UnitDefinition
-    time_unit: UnitDefinition
     data_type: DataTypes
     prepared: Optional[float] = Field(default=None)
     data: list[float] = Field(default_factory=list)
     time: list[float] = Field(default_factory=list)
+    time_unit: Optional[UnitDefinition] = Field(default=None)
     is_simulated: bool = False
 
     # JSON-LD fields
@@ -1794,8 +1795,8 @@ class MeasurementData(BaseModel):
         serialization_alias="@context",
         default_factory=lambda: {
             "enzml": "http://www.enzymeml.org/v2/",
-            "schema": "https://schema.org/",
             "OBO": "http://purl.obolibrary.org/obo/",
+            "schema": "https://schema.org/",
             "species_id": {
                 "@type": "@id",
             },
@@ -1892,8 +1893,8 @@ class UnitDefinition(BaseModel):
         serialization_alias="@context",
         default_factory=lambda: {
             "enzml": "http://www.enzymeml.org/v2/",
-            "schema": "https://schema.org/",
             "OBO": "http://purl.obolibrary.org/obo/",
+            "schema": "https://schema.org/",
         },
     )
 
@@ -2022,8 +2023,8 @@ class BaseUnit(BaseModel):
         serialization_alias="@context",
         default_factory=lambda: {
             "enzml": "http://www.enzymeml.org/v2/",
-            "schema": "https://schema.org/",
             "OBO": "http://purl.obolibrary.org/obo/",
+            "schema": "https://schema.org/",
         },
     )
 
diff --git a/schemes/enzymeml.json b/schemes/enzymeml.json
index 6d86f9e..ab92a95 100644
--- a/schemes/enzymeml.json
+++ b/schemes/enzymeml.json
@@ -88,6 +88,92 @@
   },
   "description": "This is the root object that composes all objects found in an EnzymeML document. It also includes general metadata such as the name of the document, when it was created/modified, and references to publications, databases, and arbitrary links to the web.",
   "definitions": {
+    "Parameter": {
+      "title": "Parameter",
+      "type": "object",
+      "properties": {
+        "id": {
+          "title": "id",
+          "description": "Unique identifier of the parameter.",
+          "term": "schema:identifier",
+          "type": "string"
+        },
+        "name": {
+          "title": "name",
+          "description": "Name of the parameter.",
+          "type": "string"
+        },
+        "symbol": {
+          "title": "symbol",
+          "description": "Symbol of the parameter.",
+          "type": "string"
+        },
+        "value": {
+          "title": "value",
+          "description": "Numerical value of the estimated parameter.",
+          "type": "number"
+        },
+        "unit": {
+          "$ref": "#/definitions/UnitDefinition"
+        },
+        "initial_value": {
+          "title": "initial_value",
+          "description": "Initial value that was used for the parameter estimation.",
+          "type": "number"
+        },
+        "upper": {
+          "title": "upper",
+          "description": "Upper bound of the estimated parameter.",
+          "type": "number"
+        },
+        "lower": {
+          "title": "lower",
+          "description": "Lower bound of the estimated parameter.",
+          "type": "number"
+        },
+        "stderr": {
+          "title": "stderr",
+          "description": "Standard error of the estimated parameter.",
+          "type": "number"
+        },
+        "constant": {
+          "title": "constant",
+          "description": "Specifies if this parameter is constant",
+          "type": "boolean"
+        }
+      },
+      "description": "This object describes the parameters of the kinetic model and can include all estimated values."
+    },
+    "Complex": {
+      "title": "Complex",
+      "type": "object",
+      "properties": {
+        "id": {
+          "title": "id",
+          "description": "Unique identifier of the complex.",
+          "term": "schema:identifier",
+          "type": "string"
+        },
+        "name": {
+          "title": "name",
+          "term": "schema:name",
+          "type": "string"
+        },
+        "constant": {
+          "title": "constant",
+          "type": "boolean"
+        },
+        "participants": {
+          "title": "participants",
+          "description": "Array of IDs the complex contains",
+          "type": "array",
+          "items": {
+            "type": "string"
+          }
+        }
+      },
+      "description": "This object describes complexes made of reactants and/or proteins that were used or produced in the course of the experiment."
+    },
     "SmallMolecule": {
       "title": "SmallMolecule",
       "type": "object",
@@ -140,6 +226,59 @@
       },
       "description": "This object describes the reactants that were used or produced in the course of the experiment."
     },
+    "Equation": {
+      "title": "Equation",
+      "type": "object",
+      "properties": {
+        "species_id": {
+          "title": "species_id",
+          "description": "Internal identifier to a species defined in the EnzymeMLDocument, given it is a rate equation.",
+          "type": "string"
+        },
+        "equation": {
+          "title": "equation",
+          "description": "Mathematical expression of the equation.",
+          "type": "string"
+        },
+        "equation_type": {
+          "title": "equation_type",
+          "$ref": "#/definitions/EquationType"
+        },
+        "variables": {
+          "type": "array",
+          "items": {
+            "$ref": "#/definitions/Variable"
+          }
+        }
+      },
+      "description": "This object describes an equation that can be used to model the kinetics of a reaction. There are different types of equations that can be used to model the kinetics of a reaction. The equation can be an ordinary differential equation, a rate law or assignment rule."
+    },
+    "Creator": {
+      "title": "Creator",
+      "type": "object",
+      "properties": {
+        "given_name": {
+          "title": "given_name",
+          "description": "Given name of the author or contributor.",
+          "term": "schema:givenName",
+          "type": "string"
+        },
+        "family_name": {
+          "title": "family_name",
+          "description": "Family name of the author or contributor.",
+          "term": "schema:familyName",
+          "type": "string"
+        },
+        "mail": {
+          "title": "mail",
+          "description": "Email address of the author or contributor.",
+          "term": "schema:email",
+          "type": "string"
+        }
+      },
+      "description": "The creator object contains all information about authors that contributed to the resulting document.",
+      "term": "schema:person"
+    },
     "Measurement": {
       "title": "Measurement",
       "type": "object",
@@ -184,32 +323,6 @@
       },
       "description": "This object describes the result of a measurement, which includes time course data of any type defined in DataTypes. It includes initial concentrations of all species used in a single measurement."
     },
-    "Creator": {
-      "title": "Creator",
-      "type": "object",
-      "properties": {
-        "given_name": {
-          "title": "given_name",
-          "description": "Given name of the author or contributor.",
-          "term": "schema:givenName",
-          "type": "string"
-        },
-        "family_name": {
-          "title": "family_name",
-          "description": "Family name of the author or contributor.",
-          "term": "schema:familyName",
-          "type": "string"
-        },
-        "mail": {
-          "title": "mail",
-          "description": "Email address of the author or contributor.",
-          "term": "schema:email",
-          "type": "string"
-        }
-      },
-      "description": "The creator object contains all information about authors that contributed to the resulting document.",
-      "term": "schema:person"
-    },
     "Vessel": {
       "title": "Vessel",
       "type": "object",
@@ -244,6 +357,46 @@
       "description": "This object describes vessels in which the experiment has been carried out. These can include any type of vessel used in biocatalytic experiments.",
       "term": "OBO:OBI_0400081"
     },
+    "Reaction": {
+      "title": "Reaction",
+      "type": "object",
+      "properties": {
+        "id": {
+          "title": "id",
+          "description": "Unique identifier of the reaction.",
+          "term": "schema:identifier",
+          "type": "string"
+        },
+        "name": {
+          "title": "name",
+          "description": "Name of the reaction.",
+          "type": "string"
+        },
+        "reversible": {
+          "title": "reversible",
+          "description": "Whether the reaction is reversible or irreversible",
+          "type": "boolean"
+        },
+        "kinetic_law": {
+          "$ref": "#/definitions/Equation"
+        },
+        "species": {
+          "type": "array",
+          "items": {
+            "$ref": "#/definitions/ReactionElement"
+          }
+        },
+        "modifiers": {
+          "title": "modifiers",
+          "description": "List of reaction elements that are not part of the reaction but influence it.",
+          "type": "array",
+          "items": {
+            "type": "string"
+          }
+        }
+      },
+      "description": "This object describes a chemical or enzymatic reaction that was investigated in the course of the experiment. All species used within this object need to be part of the data model."
+    },
     "Protein": {
       "title": "Protein",
       "type": "object",
@@ -303,159 +456,6 @@
       },
       "description": "This object describes the proteins that were used or formed throughout the experiment.",
       "term": "schema:Protein"
-    },
-    "Equation": {
-      "title": "Equation",
-      "type": "object",
-      "properties": {
-        "species_id": {
-          "title": "species_id",
-          "description": "Internal identifier to a species defined in the EnzymeMLDocument, given it is a rate equation.",
-          "type": "string"
-        },
-        "equation": {
-          "title": "equation",
-          "description": "Mathematical expression of the equation.",
-          "type": "string"
-        },
-        "equation_type": {
-          "title": "equation_type",
-          "$ref": "#/definitions/EquationType"
-        },
-        "variables": {
-          "type": "array",
-          "items": {
-            "$ref": "#/definitions/Variable"
-          }
-        }
-      },
-      "description": "This object describes an equation that can be used to model the kinetics of a reaction. There are different types of equations that can be used to model the kinetics of a reaction. The equation can be an ordinary differential equation, a rate law or assignment rule."
-    },
-    "Complex": {
-      "title": "Complex",
-      "type": "object",
-      "properties": {
-        "id": {
-          "title": "id",
-          "description": "Unique identifier of the complex.",
-          "term": "schema:identifier",
-          "type": "string"
-        },
-        "name": {
-          "title": "name",
-          "term": "schema:name",
-          "type": "string"
-        },
-        "constant": {
-          "title": "constant",
-          "type": "boolean"
-        },
-        "participants": {
-          "title": "participants",
-          "description": "Array of IDs the complex contains",
-          "type": "array",
-          "items": {
-            "type": "string"
-          }
-        }
-      },
-      "description": "This object describes complexes made of reactants and/or proteins that were used or produced in the course of the experiment."
-    },
-    "Reaction": {
-      "title": "Reaction",
-      "type": "object",
-      "properties": {
-        "id": {
-          "title": "id",
-          "description": "Unique identifier of the reaction.",
-          "term": "schema:identifier",
-          "type": "string"
-        },
-        "name": {
-          "title": "name",
-          "description": "Name of the reaction.",
-          "type": "string"
-        },
-        "reversible": {
-          "title": "reversible",
-          "description": "Whether the reaction is reversible or irreversible",
-          "type": "boolean"
-        },
-        "kinetic_law": {
-          "$ref": "#/definitions/Equation"
-        },
-        "species": {
-          "type": "array",
-          "items": {
-            "$ref": "#/definitions/ReactionElement"
-          }
-        },
-        "modifiers": {
-          "title": "modifiers",
-          "description": "List of reaction elements that are not part of the reaction but influence it.",
-          "type": "array",
-          "items": {
-            "type": "string"
-          }
-        }
-      },
-      "description": "This object describes a chemical or enzymatic reaction that was investigated in the course of the experiment. All species used within this object need to be part of the data model."
-    },
-    "Parameter": {
-      "title": "Parameter",
-      "type": "object",
-      "properties": {
-        "id": {
-          "title": "id",
-          "description": "Unique identifier of the parameter.",
-          "term": "schema:identifier",
-          "type": "string"
-        },
-        "name": {
-          "title": "name",
-          "description": "Name of the parameter.",
-          "type": "string"
-        },
-        "symbol": {
-          "title": "symbol",
-          "description": "Symbol of the parameter.",
-          "type": "string"
-        },
-        "value": {
-          "title": "value",
-          "description": "Numerical value of the estimated parameter.",
-          "type": "number"
-        },
-        "unit": {
-          "$ref": "#/definitions/UnitDefinition"
-        },
-        "initial_value": {
-          "title": "initial_value",
-          "description": "Initial value that was used for the parameter estimation.",
-          "type": "number"
-        },
-        "upper": {
-          "title": "upper",
-          "description": "Upper bound of the estimated parameter.",
-          "type": "number"
-        },
-        "lower": {
-          "title": "lower",
-          "description": "Lower bound of the estimated parameter.",
-          "type": "number"
-        },
-        "stderr": {
-          "title": "stderr",
-          "description": "Standard error of the estimated parameter.",
-          "type": "number"
-        },
-        "constant": {
-          "title": "constant",
-          "description": "Specifies if this parameter is constant",
-          "type": "boolean"
-        }
-      },
-      "description": "This object describes the parameters of the kinetic model and can include all estimated values."
     }
   }
 }
\ No newline at end of file
diff --git a/schemes/enzymeml.xsd b/schemes/enzymeml.xsd
index c847052..c19383a 100644
--- a/schemes/enzymeml.xsd
+++ b/schemes/enzymeml.xsd
@@ -656,13 +656,6 @@
                     </xs:documentation>
                 </xs:annotation>
             </xs:element>
-            <xs:element name="time_unit" type="UnitDefinitionType">
-                <xs:annotation>
-                    <xs:documentation>
-                        Time unit of the replicate.
-                    </xs:documentation>
-                </xs:annotation>
-            </xs:element>
             <xs:element name="data_type" type="DataTypesType">
                 <xs:annotation>
                     <xs:documentation>
@@ -677,20 +670,27 @@
                     </xs:documentation>
                 </xs:annotation>
             </xs:element>
-            <xs:element name="data" type="xs:float"  maxOccurs="unbounded" minOccurs="1">
+            <xs:element name="data" type="xs:float"  maxOccurs="unbounded">
                 <xs:annotation>
                     <xs:documentation>
                         Data that was measured.
                     </xs:documentation>
                 </xs:annotation>
             </xs:element>
-            <xs:element name="time" type="xs:float"  maxOccurs="unbounded" minOccurs="1">
+            <xs:element name="time" type="xs:float"  maxOccurs="unbounded">
                 <xs:annotation>
                     <xs:documentation>
                         Time steps of the replicate.
                     </xs:documentation>
                 </xs:annotation>
             </xs:element>
+            <xs:element name="time_unit" type="UnitDefinitionType">
+                <xs:annotation>
+                    <xs:documentation>
+                        Time unit of the replicate.
+                    </xs:documentation>
+                </xs:annotation>
+            </xs:element>
             <xs:element name="is_simulated" type="xs:boolean" default="false">
                 <xs:annotation>
                     <xs:documentation>
diff --git a/specifications/enzymeml.md b/specifications/enzymeml.md
index 5568eaf..0b2a0e7 100644
--- a/specifications/enzymeml.md
+++ b/specifications/enzymeml.md
@@ -351,22 +351,22 @@ This object describes a single entity of a measurement, which corresponds to one
 - __data_unit__
   - Type: UnitDefinition
   - Description: SI unit of the data that was measured.
-- __data__
+- data
   - Type: float[]
   - Description: Data that was measured.
-- __time__
+- time
   - Type: float[]
   - Description: Time steps of the replicate.
-- __time_unit__
+- time_unit
   - Type: UnitDefinition
   - Description: Time unit of the replicate.
+- __data_type__
+  - Type: DataTypes
+  - Description: Type of data that was measured (e.g. concentration)
 - __is_simulated__
   - Type: boolean
   - Description: Whether or not the data has been generated by simulation.
   - Default: False
-- __data_type__
-  - Type: DataTypes
-  - Description: Type of data that was measured (e.g. concentration)
 
 ## Enumerations
 
diff --git a/typescript/src/index.ts b/typescript/src/index.ts
index f262ab1..53f6097 100644
--- a/typescript/src/index.ts
+++ b/typescript/src/index.ts
@@ -416,24 +416,24 @@ export const MeasurementCodec = D.lazy("Measurement", () => D.struct({
     * @param initial - Initial amount of the measurement data. This must be the same as the
              first data point in the
     * @param data_unit - SI unit of the data that was measured.
-    * @param time_unit - Time unit of the replicate.
     * @param data_type - Type of data that was measured (e.g. concentration)
     * @param prepared - Amount of the reactant before the measurement. This field should be
              used for specifying the prepared amount of a species in
              the reaction mix. Not to be confused with
     * @param data - Data that was measured.
     * @param time - Time steps of the replicate.
+    * @param time_unit - Time unit of the replicate.
     * @param is_simulated - Whether or not the data has been generated by simulation.
 **/
 export interface MeasurementData extends JsonLd {
   species_id: string;
   initial: number;
   data_unit: UnitDefinition;
-  time_unit: UnitDefinition;
   data_type: DataTypes;
   prepared?: number | null;
-  data: number[];
-  time: number[];
+  data?: number[] | null;
+  time?: number[] | null;
+  time_unit?: UnitDefinition | null;
   is_simulated: boolean;
 }
 
@@ -441,11 +441,11 @@ export const MeasurementDataCodec = D.lazy("MeasurementData", () => D.struct({
     species_id: D.string,
     initial: D.number,
     data_unit: UnitDefinitionCodec,
-    time_unit: UnitDefinitionCodec,
     data_type: DataTypesCodec,
     prepared: D.nullable(D.number),
     data: D.array(D.number),
     time: D.array(D.number),
+    time_unit: D.nullable(UnitDefinitionCodec),
     is_simulated: D.boolean,
 }));