identifier: METPO:1000641 label: chemotrophic definition: A trophic type in which an organism obtains energy from chemical oxidation of either inorganic or organic compounds. definition_source: DOI:10.1016/B978-012373944-5.00083-3 trait_category: PHYSIOLOGY term_kind: CLASS mapping_status: REVIEWED parent_traits: - METPO:1000631 synonyms: - synonym_text: TT_chemotroph synonym_type: RELATED_SYNONYM source: metpo.owl - synonym_text: chemotroph synonym_type: RELATED_SYNONYM source: metpo.owl evidence: - reference: DOI:10.1016/B978-012373944-5.00083-3 snippet: chemical energy notes: Encyclopedia chapter classifies chemotrophy by chemical energy sources. - reference: DOI:10.1016/j.bbabio.2008.09.008 snippet: free energy of a redox reaction notes: Review supports chemical redox reactions as energy sources for respiratory energy conservation. causal_graphs: - graph_id: chemotrophic_chemical_redox_energy title: Chemotrophic chemical redox energy conservation description: DOI-backed graph linking reduced chemical substrates, inorganic and organic donor examples, redox reactions, respiratory electron transfer, proton motive force, and ATP. nodes: - node_id: chemotrophic_trait label: chemotrophic node_type: TRAIT grounding: METPO:1000641 description: Trophic type deriving energy from chemical oxidation. - node_id: reduced_chemical_substrate label: reduced chemical substrate node_type: CHEMICAL description: Electron donor oxidized for metabolic energy. - node_id: inorganic_compound label: inorganic compound node_type: CHEMICAL description: Inorganic electron donor used by chemolithotrophs. - node_id: organic_compound label: organic compound node_type: CHEMICAL description: Organic electron donor used by chemoorganotrophs. grounding: CHEBI:50860 - node_id: redox_reaction label: redox reaction node_type: MOLECULAR_FUNCTION description: Oxidation-reduction reaction releasing usable free energy. grounding: GO:0016491 - node_id: respiratory_chain label: respiratory chain node_type: PATHWAY description: Membrane electron-transfer system conserving redox energy. grounding: GO:0022904 - node_id: terminal_electron_acceptor label: terminal electron acceptor node_type: CHEMICAL description: Oxidized acceptor receiving electrons during respiration. grounding: METPO:1007504 - node_id: proton_motive_force label: proton motive force node_type: STATE description: Electrochemical ion gradient generated by electron transport. grounding: METPO:1007500 - node_id: atp label: ATP node_type: CHEMICAL grounding: CHEBI:30616 description: Energy carrier produced by chemotrophic metabolism. - node_id: quinone_quinol_cycling label: quinone/quinol cycling node_type: BIOLOGICAL_PROCESS description: Membrane quinone reduction/oxidation cycle that translocates protons. - node_id: redox_loop label: redox loop node_type: BIOLOGICAL_PROCESS description: Electron-transfer arrangement coupling electron flow to net transmembrane proton transfer without active pumping. - node_id: proton_pumping label: proton pumping node_type: BIOLOGICAL_PROCESS description: Active vectorial translocation of protons across the coupling membrane by electron-transport complexes. - node_id: net_proton_transfer label: net proton transfer across membrane node_type: BIOLOGICAL_PROCESS description: Net movement of protons across the coupling membrane that establishes the electrochemical gradient. edges: - subject: chemotrophic_trait predicate: uses energy source object: reduced_chemical_substrate description: Chemotrophy uses chemical substrates as energy sources. evidence: - reference: DOI:10.1016/B978-012373944-5.00083-3 snippet: chemical energy notes: Supports chemical energy as the defining chemotrophic energy source. predicate_id: METPO:2000010 - subject: inorganic_compound predicate: example of object: reduced_chemical_substrate description: Inorganic substrates are chemical energy sources in lithotrophy. evidence: - reference: DOI:10.1016/B978-0-12-378630-2.00219-X snippet: oxidize inorganic atoms or molecules notes: Supports inorganic chemical substrates in chemolithotrophic metabolism. predicate_id: rdfs:subClassOf - subject: organic_compound predicate: example of object: reduced_chemical_substrate description: Organic substrates are chemical energy sources in organotrophy. evidence: - reference: DOI:10.1016/B978-012373944-5.00083-3 snippet: reduced organic compound notes: Supports reduced organic compounds as chemical energy substrates. predicate_id: rdfs:subClassOf - subject: reduced_chemical_substrate predicate: oxidized by object: redox_reaction description: Chemical energy is released through oxidation-reduction chemistry. evidence: - reference: DOI:10.1016/j.bbabio.2008.09.008 snippet: free energy of a redox reaction notes: Supports redox reactions as the energy source for chemiosmotic conservation. - subject: redox_reaction predicate: feeds electrons into object: respiratory_chain description: Redox reactions can feed electrons into membrane respiratory chains. evidence: - reference: DOI:10.1016/j.bbabio.2008.09.008 snippet: membrane-bound electron transport chain notes: Supports membrane electron transport in respiratory energy conservation. predicate_id: METPO:2007402 - subject: respiratory_chain predicate: transfers electrons to object: terminal_electron_acceptor description: Respiratory chains transfer electrons to terminal acceptors. evidence: - reference: DOI:10.1128/mmbr.61.4.533-616.1997 snippet: terminal electron acceptor notes: Supports terminal electron acceptors in respiratory metabolism. predicate_id: METPO:2007403 - subject: respiratory_chain predicate: generates object: proton_motive_force description: Respiratory electron transfer generates an ion gradient. evidence: - reference: DOI:10.1016/j.bbabio.2008.09.008 snippet: generation of an electrochemical ion gradient notes: Supports ion-gradient formation by electron transport. predicate_id: biolink:produces - subject: proton_motive_force predicate: drives production of object: atp description: Proton motive force drives ATP synthesis. evidence: - reference: DOI:10.1016/j.bbabio.2008.09.008 snippet: drives ATP synthesis notes: Supports ATP synthesis from chemotrophic respiratory energy conservation. predicate_id: biolink:produces - subject: proton_motive_force predicate: can be built by object: quinone_quinol_cycling description: Proton motive force can be generated by quinone/quinol cycling. evidence: - reference: DOI:10.1016/j.bbabio.2008.09.008 notes: The proton motive force (pmf) can be built up by different mechanisms like proton pumping, quinone/quinol cycling or by a redox loop. - subject: proton_pumping predicate: contributes to generation of object: proton_motive_force description: Active proton pumping contributes to building the proton motive force. evidence: - reference: DOI:10.1016/j.bbabio.2008.09.008 notes: The proton motive force (pmf) can be built up by different mechanisms like proton pumping, quinone/quinol cycling or by a redox loop. - subject: redox_loop predicate: contributes to generation of object: proton_motive_force description: A redox loop contributes to building the proton motive force. evidence: - reference: DOI:10.1016/j.bbabio.2008.09.008 notes: The proton motive force (pmf) can be built up by different mechanisms like proton pumping, quinone/quinol cycling or by a redox loop. - subject: redox_loop predicate: couples electron transport to object: net_proton_transfer description: A redox loop couples electron transport to net proton transfer across the membrane without proton pumping. evidence: - reference: DOI:10.1016/j.bbabio.2008.09.008 notes: The latter couples electron transport to a net proton transfer across the membrane without proton pumping. curation_history: - timestamp: '2026-05-05T01:35:46.872607+00:00' curator: seed_from_metpo action: SEEDED_FROM_METPO changes: imported from data/raw/metpo.owl (CLASS) llm_assisted: false - timestamp: '2026-05-09T00:00:00-07:00' curator: codex action: ADDED_CAUSAL_GRAPH changes: Added DOI-backed causal graph for chemical substrate oxidation, respiratory electron transfer, proton motive force, and ATP synthesis. llm_assisted: true - timestamp: '2026-05-20T03:35:31Z' curator: claude action: GROUND_CAUSAL_PREDICATES changes: Grounded 1 causal-edge predicate_id field(s) via mappings/predicate_grounding.tsv (METPO:2000010×1). llm_assisted: true - timestamp: '2026-05-23T08:21:50Z' curator: claude action: GROUND_CAUSAL_PREDICATES changes: Grounded 3 causal-edge predicate_id field(s) via mappings/predicate_grounding.tsv (rdfs:subClassOf×2, biolink:produces×1). llm_assisted: true - timestamp: '2026-05-23T21:30:07Z' curator: claude action: GROUND_CAUSAL_PREDICATES changes: Grounded 2 causal-edge predicate_id field(s) via mappings/predicate_grounding.tsv (METPO:2007402×1, METPO:2007403×1). llm_assisted: true - timestamp: '2026-05-24T04:38:01Z' curator: claude action: GROUND_CAUSAL_NODES changes: Grounded 2 causal-node grounding field(s) via mappings/node_grounding.tsv (GO:0016491×1, GO:0022904×1). llm_assisted: true - timestamp: '2026-05-24T04:41:04Z' curator: claude action: GROUND_CAUSAL_NODES changes: Grounded 2 causal-node grounding field(s) via mappings/node_grounding.tsv (METPO:1007504×1, METPO:1007500×1). llm_assisted: true - timestamp: '2026-05-24T08:14:33Z' curator: claude action: GROUND_CAUSAL_NODES changes: Grounded 1 causal-node grounding field(s) via mappings/node_grounding.tsv (CHEBI:50860×1). llm_assisted: true - timestamp: '2026-05-26T02:30:13Z' curator: claude action: RETYPE_CAUSAL_NODES changes: 'Re-typed 1 causal-node node_type field(s) to align with CausalNodeTypeEnum semantics: proton motive force: BIOLOGICAL_PROCESS → STATE ×1.' llm_assisted: true - timestamp: '2026-06-13T21:03:27Z' curator: claude action: GROUND_CAUSAL_PREDICATES changes: Grounded 1 causal-edge predicate_id field(s) via mappings/predicate_grounding.tsv (biolink:produces×1). llm_assisted: true - timestamp: '2026-06-23T00:00:00Z' curator: claude action: ENRICH_CAUSAL_GRAPH changes: Added 4 evidence-backed generic edges (4 new nodes) from the deep-research report. llm_assisted: true