mitochondrial inner membrane

GO:0005743 · Membrane organelle · Membrane · Proposed

The inner, i.e. lumen-facing, lipid bilayer of the mitochondrial envelope. It is highly folded to form cristae. [GO:0005743]

Synonyms: inner mitochondrial membrane; inner mitochondrion membrane; mitochondrion inner membrane

Part of: mitochondrial envelope (GO:0005740)

Has part: mitochondrial crista (GO:0030061)

UniProt location names: UniProt Consortium, CC BY 4.0. Reference label and route sources.

Components

Component	Type	Part of / acts on	Grounding	Genes	Stoichiometry	Essential	Role
mitochondrial inner lipid bilayer	Lipid	part of	Reviewed label only (reviewed name; no accession asserted)			ESSENTIAL	Lumen-facing lipid bilayer that forms crista folds and separates the mitochondrial matrix from the intermembrane space. `GO:0005743` GO:0005743 defines the mitochondrial inner membrane as the lumen-facing lipid bilayer of the mitochondrial envelope.

Taxonomic distribution

NCBITaxon:2759 Eukaryota — VARIABLE: Canonical mitochondrial inner membranes occur with canonical mitochondria across eukaryotes, while some anaerobic lineages carry reduced mitochondrion-related organelles instead. [GO:0005743]
NCBITaxon:4932 Saccharomyces cerevisiae — COMMON: Budding-yeast mitochondria have an inner-membrane proteome enriched for oxidative-phosphorylation machinery. [DOI:10.1073/pnas.2135385100]

Canonical examples

NCBITaxon:4932 Saccharomyces cerevisiae — Budding-yeast model used for purified mitochondrial proteomics and for genetic and electron-tomographic studies of mitochondrial inner-membrane architecture. [DOI:10.7554/elife.07739]

Functions

oxidative phosphorylation GO:0006119 — Inner-membrane respiratory-chain activity contributes to ATP synthesis by coupling metabolite oxidation to a proton gradient across the mitochondrial inner membrane.
- GO:0006119 GO:0006119 defines oxidative phosphorylation as ATP formation coupled to respiratory-chain oxidation and proton-gradient formation.
- DOI:10.1073/pnas.2135385100 Sickmann et al. 2003 recovered oxidative-phosphorylation complexes in the purified budding-yeast mitochondrial proteome.

Mechanism graphs

Mitochondrial inner membrane topology (FUNCTION)

The mitochondrial inner membrane is the lumen-facing mitochondrial envelope bilayer that folds into cristae, bounds the matrix, and delimits the intermembrane space.

Subject	Predicate	Object	Evidence
mitochondrial inner membrane	is part of	mitochondrial envelope	`GO:0005743` GO:0005743 defines the inner membrane as the inner lipid bilayer of the mitochondrial envelope.
mitochondrial crista	is part of	mitochondrial inner membrane	`GO:0030061` GO:0030061 defines a crista as an inward fold of the mitochondrial inner membrane.
mitochondrial inner membrane	bounds	mitochondrial matrix	`GO:0005743` GO:0005743 defines the inner membrane as lumen-facing. `GO:0005759` GO:0005759 identifies the mitochondrial matrix as the mitochondrial matrix space or lumen.
mitochondrial inner membrane	delimits	mitochondrial intermembrane space	`GO:0005758` GO:0005758 defines the intermembrane space as the region between the inner and outer lipid bilayers of the mitochondrial envelope.
mitochondrial inner membrane	supports	oxidative phosphorylation	`DOI:10.1073/pnas.2135385100` Sickmann et al. 2003 recovered oxidative-phosphorylation complexes in the purified budding-yeast mitochondrial proteome.

Discussions

CURATION_TODO (OPEN): Resolve an exact source-neutral grounding for the lipid constituent of the mitochondrial inner membrane. GO:0005743 identifies the whole mitochondrial inner membrane, but the lipid-bilayer constituent is intentionally left as reviewed-label-only until an exact source-neutral lipid or membrane-constituent CURIE is curated.

Evidence

GO:0005743 Gene Ontology cellular-component term for mitochondrial inner membrane.
GO:0019866 Gene Ontology cellular-component parent term for organelle inner membrane.
GO:0031966 Gene Ontology cellular-component parent term for mitochondrial membrane.
GO:0005740 Gene Ontology cellular-component term for the mitochondrial envelope.
GO:0030061 Gene Ontology cellular-component term for mitochondrial crista.
GO:0005758 Gene Ontology cellular-component term for mitochondrial intermembrane space.
GO:0005759 Gene Ontology cellular-component term for mitochondrial matrix.
GO:0006119 Gene Ontology biological-process term for oxidative phosphorylation.
DOI:10.1073/pnas.2135385100 Sickmann et al. 2003, 'The proteome of Saccharomyces cerevisiae mitochondria', Proceedings of the National Academy of Sciences.
DOI:10.7554/elife.07739 Friedman et al. 2015, 'MICOS coordinates with respiratory complexes and lipids to establish mitochondrial inner membrane architecture', eLife.
DOI:10.1038/nature12985 Friedman and Nunnari 2014, 'Mitochondrial form and function', Nature.

Curation history

2026-09-13T23:33:59Z codex · CREATED_RECORD — Scaffolded by scripts/new_record.py
2026-09-13T23:34:41Z codex · EXPANDED_RECORD — Added GO parentage, mitochondrial-envelope parthood, crista containment, a reviewed-label-only lipid-bilayer component, Eukaryota and Saccharomyces scope, oxidative-phosphorylation function evidence, a nonmechanistic inner-membrane topology graph, and a lipid-bilayer grounding TODO.

Source: data/structures/membrane_organelle/mitochondrial_inner_membrane.yaml