Reactome | H+ [mitochondrial intermembrane space]

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Cellular responses to external stimuli (Bos taurus)

- Cellular responses to stress (Bos taurus)
  - Detoxification of Reactive Oxygen Species (Bos taurus)
    - SOD1 catalyzes 2H+ + O2.- => O2 + H2O2 (mitochondrial intermembrane space) (Bos taurus)
      - H+ [mitochondrial intermembrane space]

Gene expression (Transcription) (Bos taurus)

- RNA Polymerase II Transcription (Bos taurus)
  - Generic Transcription Pathway (Bos taurus)
    - Transcriptional Regulation by TP53 (Bos taurus)
      - TP53 Regulates Metabolic Genes (Bos taurus)
        
        Electron transfer from reduced cytochrome c to molecular oxygen (Bos taurus)
        
        H+ [mitochondrial intermembrane space]

Metabolism (Bos taurus)

- The citric acid (TCA) cycle and respiratory electron transport (Bos taurus)
  - Respiratory electron transport, ATP synthesis by chemiosmotic coupling, and heat production by uncoupling proteins. (Bos taurus)
    - Formation of ATP by chemiosmotic coupling (Bos taurus)
      - Enzyme-bound ATP is released (Bos taurus)
        
        H+ [mitochondrial intermembrane space]
    - Mitochondrial Uncoupling (Bos taurus)
      - The proton buffering model (Bos taurus)
        
        Protons are translocated from the intermembrane space to the matrix (Bos taurus)
        
        H+ [mitochondrial intermembrane space]
    - Respiratory electron transport (Bos taurus)
      - Complex I oxidises NADH to NAD+, reduces CoQ to QH2 (Bos taurus)
        
        H+ [mitochondrial intermembrane space]
      - Electron transfer from reduced cytochrome c to molecular oxygen (Bos taurus)
        
        H+ [mitochondrial intermembrane space]

Signal Transduction (Bos taurus)

- Signaling by Nuclear Receptors (Bos taurus)
  - Signaling by Retinoic Acid (Bos taurus)
    - RA biosynthesis pathway (Bos taurus)
      - RDH13 reduces atRAL to atROL (Bos taurus)
        
        H+ [mitochondrial intermembrane space]

Transport of small molecules (Bos taurus)

- Ion channel transport (Bos taurus)
  - Stimuli-sensing channels (Bos taurus)
    - SLC9B2 exchanges Na+, Li+ for H+ (Bos taurus)
      - H+ [mitochondrial intermembrane space]

Cellular responses to external stimuli (Caenorhabditis elegans)

- Cellular responses to stress (Caenorhabditis elegans)
  - Detoxification of Reactive Oxygen Species (Caenorhabditis elegans)
    - SOD1 catalyzes 2H+ + O2.- => O2 + H2O2 (mitochondrial intermembrane space) (Caenorhabditis elegans)
      - H+ [mitochondrial intermembrane space]

Metabolism (Caenorhabditis elegans)

- The citric acid (TCA) cycle and respiratory electron transport (Caenorhabditis elegans)
  - Respiratory electron transport, ATP synthesis by chemiosmotic coupling, and heat production by uncoupling proteins. (Caenorhabditis elegans)
    - Formation of ATP by chemiosmotic coupling (Caenorhabditis elegans)
      - Enzyme-bound ATP is released (Caenorhabditis elegans)
        
        H+ [mitochondrial intermembrane space]
    - Mitochondrial Uncoupling (Caenorhabditis elegans)
      - The proton buffering model (Caenorhabditis elegans)
        
        Protons are translocated from the intermembrane space to the matrix (Caenorhabditis elegans)
        
        H+ [mitochondrial intermembrane space]

Signal Transduction (Caenorhabditis elegans)

- Signaling by Nuclear Receptors (Caenorhabditis elegans)
  - Signaling by Retinoic Acid (Caenorhabditis elegans)
    - RA biosynthesis pathway (Caenorhabditis elegans)
      - RDH13 reduces atRAL to atROL (Caenorhabditis elegans)
        
        H+ [mitochondrial intermembrane space]

Transport of small molecules (Caenorhabditis elegans)

- Ion channel transport (Caenorhabditis elegans)
  - Stimuli-sensing channels (Caenorhabditis elegans)
    - SLC9B2 exchanges Na+, Li+ for H+ (Caenorhabditis elegans)
      - H+ [mitochondrial intermembrane space]

Cellular responses to external stimuli (Canis familiaris)

- Cellular responses to stress (Canis familiaris)
  - Detoxification of Reactive Oxygen Species (Canis familiaris)
    - SOD1 catalyzes 2H+ + O2.- => O2 + H2O2 (mitochondrial intermembrane space) (Canis familiaris)
      - H+ [mitochondrial intermembrane space]

Gene expression (Transcription) (Canis familiaris)

- RNA Polymerase II Transcription (Canis familiaris)
  - Generic Transcription Pathway (Canis familiaris)
    - Transcriptional Regulation by TP53 (Canis familiaris)
      - TP53 Regulates Metabolic Genes (Canis familiaris)
        
        Electron transfer from reduced cytochrome c to molecular oxygen (Canis familiaris)
        
        H+ [mitochondrial intermembrane space]

Metabolism (Canis familiaris)

- The citric acid (TCA) cycle and respiratory electron transport (Canis familiaris)
  - Respiratory electron transport, ATP synthesis by chemiosmotic coupling, and heat production by uncoupling proteins. (Canis familiaris)
    - Formation of ATP by chemiosmotic coupling (Canis familiaris)
      - Enzyme-bound ATP is released (Canis familiaris)
        
        H+ [mitochondrial intermembrane space]
    - Mitochondrial Uncoupling (Canis familiaris)
      - The proton buffering model (Canis familiaris)
        
        Protons are translocated from the intermembrane space to the matrix (Canis familiaris)
        
        H+ [mitochondrial intermembrane space]
    - Respiratory electron transport (Canis familiaris)

Signal Transduction (Canis familiaris)

- Signaling by Nuclear Receptors (Canis familiaris)
  - Signaling by Retinoic Acid (Canis familiaris)
    - RA biosynthesis pathway (Canis familiaris)
      - RDH13 reduces atRAL to atROL (Canis familiaris)
        
        H+ [mitochondrial intermembrane space]

Cellular responses to external stimuli (Danio rerio)

- Cellular responses to stress (Danio rerio)
  - Detoxification of Reactive Oxygen Species (Danio rerio)
    - SOD1 catalyzes 2H+ + O2.- => O2 + H2O2 (mitochondrial intermembrane space) (Danio rerio)
      - H+ [mitochondrial intermembrane space]

Gene expression (Transcription) (Danio rerio)

- RNA Polymerase II Transcription (Danio rerio)
  - Generic Transcription Pathway (Danio rerio)
    - Transcriptional Regulation by TP53 (Danio rerio)
      - TP53 Regulates Metabolic Genes (Danio rerio)
        
        Electron transfer from reduced cytochrome c to molecular oxygen (Danio rerio)
        
        H+ [mitochondrial intermembrane space]

Metabolism (Danio rerio)

- The citric acid (TCA) cycle and respiratory electron transport (Danio rerio)
  - Respiratory electron transport, ATP synthesis by chemiosmotic coupling, and heat production by uncoupling proteins. (Danio rerio)
    - Formation of ATP by chemiosmotic coupling (Danio rerio)
      - Enzyme-bound ATP is released (Danio rerio)
        
        H+ [mitochondrial intermembrane space]
    - Mitochondrial Uncoupling (Danio rerio)
      - The proton buffering model (Danio rerio)
        
        Protons are translocated from the intermembrane space to the matrix (Danio rerio)
        
        H+ [mitochondrial intermembrane space]
    - Respiratory electron transport (Danio rerio)

Transport of small molecules (Danio rerio)

- Ion channel transport (Danio rerio)
  - Stimuli-sensing channels (Danio rerio)
    - SLC9B2 exchanges Na+, Li+ for H+ (Danio rerio)
      - H+ [mitochondrial intermembrane space]

Cellular responses to external stimuli (Dictyostelium discoideum)

- Cellular responses to stress (Dictyostelium discoideum)
  - Detoxification of Reactive Oxygen Species (Dictyostelium discoideum)
    - SOD1 catalyzes 2H+ + O2.- => O2 + H2O2 (mitochondrial intermembrane space) (Dictyostelium discoideum)
      - H+ [mitochondrial intermembrane space]

Metabolism (Dictyostelium discoideum)

- The citric acid (TCA) cycle and respiratory electron transport (Dictyostelium discoideum)
  - Respiratory electron transport, ATP synthesis by chemiosmotic coupling, and heat production by uncoupling proteins. (Dictyostelium discoideum)
    - Mitochondrial Uncoupling (Dictyostelium discoideum)
      - The proton buffering model (Dictyostelium discoideum)
        
        Protons are translocated from the intermembrane space to the matrix (Dictyostelium discoideum)
        
        H+ [mitochondrial intermembrane space]
    - Respiratory electron transport (Dictyostelium discoideum)
      - Electron transfer from ubiquinol to cytochrome c of complex III (Dictyostelium discoideum)
        
        H+ [mitochondrial intermembrane space]

Signal Transduction (Dictyostelium discoideum)

- Signaling by Nuclear Receptors (Dictyostelium discoideum)
  - Signaling by Retinoic Acid (Dictyostelium discoideum)
    - RA biosynthesis pathway (Dictyostelium discoideum)
      - RDH13 reduces atRAL to atROL (Dictyostelium discoideum)
        
        H+ [mitochondrial intermembrane space]

Cellular responses to external stimuli (Drosophila melanogaster)

- Cellular responses to stress (Drosophila melanogaster)
  - Detoxification of Reactive Oxygen Species (Drosophila melanogaster)
    - SOD1 catalyzes 2H+ + O2.- => O2 + H2O2 (mitochondrial intermembrane space) (Drosophila melanogaster)
      - H+ [mitochondrial intermembrane space]

Gene expression (Transcription) (Drosophila melanogaster)

- RNA Polymerase II Transcription (Drosophila melanogaster)
  - Generic Transcription Pathway (Drosophila melanogaster)
    - Transcriptional Regulation by TP53 (Drosophila melanogaster)
      - TP53 Regulates Metabolic Genes (Drosophila melanogaster)
        
        Electron transfer from reduced cytochrome c to molecular oxygen (Drosophila melanogaster)
        
        H+ [mitochondrial intermembrane space]

Metabolism (Drosophila melanogaster)

- The citric acid (TCA) cycle and respiratory electron transport (Drosophila melanogaster)
  - Respiratory electron transport, ATP synthesis by chemiosmotic coupling, and heat production by uncoupling proteins. (Drosophila melanogaster)
    - Formation of ATP by chemiosmotic coupling (Drosophila melanogaster)
      - Enzyme-bound ATP is released (Drosophila melanogaster)
        
        H+ [mitochondrial intermembrane space]
    - Mitochondrial Uncoupling (Drosophila melanogaster)
      - The proton buffering model (Drosophila melanogaster)
        
        Protons are translocated from the intermembrane space to the matrix (Drosophila melanogaster)
        
        H+ [mitochondrial intermembrane space]
    - Respiratory electron transport (Drosophila melanogaster)

Transport of small molecules (Drosophila melanogaster)

- Ion channel transport (Drosophila melanogaster)
  - Stimuli-sensing channels (Drosophila melanogaster)
    - SLC9B2 exchanges Na+, Li+ for H+ (Drosophila melanogaster)
      - H+ [mitochondrial intermembrane space]

Gene expression (Transcription) (Gallus gallus)

- RNA Polymerase II Transcription (Gallus gallus)
  - Generic Transcription Pathway (Gallus gallus)
    - Transcriptional Regulation by TP53 (Gallus gallus)
      - TP53 Regulates Metabolic Genes (Gallus gallus)
        
        Electron transfer from reduced cytochrome c to molecular oxygen (Gallus gallus)
        
        H+ [mitochondrial intermembrane space]

Metabolism (Gallus gallus)

- The citric acid (TCA) cycle and respiratory electron transport (Gallus gallus)
  - Respiratory electron transport, ATP synthesis by chemiosmotic coupling, and heat production by uncoupling proteins. (Gallus gallus)
    - Formation of ATP by chemiosmotic coupling (Gallus gallus)
      - Enzyme-bound ATP is released (Gallus gallus)
        
        H+ [mitochondrial intermembrane space]
    - Mitochondrial Uncoupling (Gallus gallus)
      - The proton buffering model (Gallus gallus)
        
        Protons are translocated from the intermembrane space to the matrix (Gallus gallus)
        
        H+ [mitochondrial intermembrane space]
    - Respiratory electron transport (Gallus gallus)

Transport of small molecules (Gallus gallus)

- Ion channel transport (Gallus gallus)
  - Stimuli-sensing channels (Gallus gallus)
    - SLC9B2 exchanges Na+, Li+ for H+ (Gallus gallus)
      - H+ [mitochondrial intermembrane space]

Cellular responses to external stimuli (Homo sapiens)

- Cellular responses to stress (Homo sapiens)
  - Detoxification of Reactive Oxygen Species (Homo sapiens)
    - SOD1 catalyzes 2H+ + O2.- => O2 + H2O2 (mitochondrial intermembrane space) (Homo sapiens)
      - H+ [mitochondrial intermembrane space]

Gene expression (Transcription) (Homo sapiens)

- RNA Polymerase II Transcription (Homo sapiens)
  - Generic Transcription Pathway (Homo sapiens)
    - Transcriptional Regulation by TP53 (Homo sapiens)
      - TP53 Regulates Metabolic Genes (Homo sapiens)
        
        Electron transfer from reduced cytochrome c to molecular oxygen (Homo sapiens)
        
        H+ [mitochondrial intermembrane space]

Metabolism (Homo sapiens)

- The citric acid (TCA) cycle and respiratory electron transport (Homo sapiens)
  - Pyruvate metabolism and Citric Acid (TCA) cycle (Homo sapiens)
    - Pyruvate metabolism (Homo sapiens)
      - MPC1:MPC2 cotransports PYR, H+ from cytosol to mitochondrial matrix (Homo sapiens)
        
        H+ [mitochondrial intermembrane space]
  - Respiratory electron transport, ATP synthesis by chemiosmotic coupling, and heat production by uncoupling proteins. (Homo sapiens)
    - Formation of ATP by chemiosmotic coupling (Homo sapiens)
      - Enzyme-bound ATP is released (Homo sapiens)
        
        H+ [mitochondrial intermembrane space]
    - Mitochondrial Uncoupling (Homo sapiens)
      - The fatty acid cycling model (Homo sapiens)
        
        FA anion picks up a proton (Homo sapiens)
        
        H+ [mitochondrial intermembrane space]
      - The proton buffering model (Homo sapiens)
        
        Protons are translocated from the intermembrane space to the matrix (Homo sapiens)
        
        H+ [mitochondrial intermembrane space]
    - Respiratory electron transport (Homo sapiens)

Signal Transduction (Homo sapiens)

- Signaling by Nuclear Receptors (Homo sapiens)
  - Signaling by Retinoic Acid (Homo sapiens)
    - RA biosynthesis pathway (Homo sapiens)
      - RDH13 reduces atRAL to atROL (Homo sapiens)
        
        H+ [mitochondrial intermembrane space]

Transport of small molecules (Homo sapiens)

- Ion channel transport (Homo sapiens)
  - Stimuli-sensing channels (Homo sapiens)
    - SLC9B2 exchanges Na+, Li+ for H+ (Homo sapiens)
      - H+ [mitochondrial intermembrane space]
- Mitochondrial calcium ion transport (Homo sapiens)
  - LETM1 exchanges protons (mitochondrial intermembrane space) for calcium (mitochondrial matrix) (Homo sapiens)
    - H+ [mitochondrial intermembrane space]

Cellular responses to external stimuli (Mus musculus)

- Cellular responses to stress (Mus musculus)
  - Detoxification of Reactive Oxygen Species (Mus musculus)
    - SOD1 catalyzes 2H+ + O2.- => O2 + H2O2 (mitochondrial intermembrane space) (Mus musculus)
      - H+ [mitochondrial intermembrane space]

Gene expression (Transcription) (Mus musculus)

- RNA Polymerase II Transcription (Mus musculus)
  - Generic Transcription Pathway (Mus musculus)
    - Transcriptional Regulation by TP53 (Mus musculus)
      - TP53 Regulates Metabolic Genes (Mus musculus)
        
        Electron transfer from reduced cytochrome c to molecular oxygen (Mus musculus)
        
        H+ [mitochondrial intermembrane space]

Metabolism (Mus musculus)

- The citric acid (TCA) cycle and respiratory electron transport (Mus musculus)
  - Respiratory electron transport, ATP synthesis by chemiosmotic coupling, and heat production by uncoupling proteins. (Mus musculus)
    - Formation of ATP by chemiosmotic coupling (Mus musculus)
      - Enzyme-bound ATP is released (Mus musculus)
        
        H+ [mitochondrial intermembrane space]
    - Mitochondrial Uncoupling (Mus musculus)
      - The proton buffering model (Mus musculus)
        
        Protons are translocated from the intermembrane space to the matrix (Mus musculus)
        
        H+ [mitochondrial intermembrane space]
    - Respiratory electron transport (Mus musculus)

Signal Transduction (Mus musculus)

- Signaling by Nuclear Receptors (Mus musculus)
  - Signaling by Retinoic Acid (Mus musculus)
    - RA biosynthesis pathway (Mus musculus)
      - RDH13 reduces atRAL to atROL (Mus musculus)
        
        H+ [mitochondrial intermembrane space]

Transport of small molecules (Mus musculus)

- Ion channel transport (Mus musculus)
  - Stimuli-sensing channels (Mus musculus)
    - SLC9B2 exchanges Na+, Li+ for H+ (Mus musculus)
      - H+ [mitochondrial intermembrane space]

Signal Transduction (Plasmodium falciparum)

- Signaling by Nuclear Receptors (Plasmodium falciparum)
  - Signaling by Retinoic Acid (Plasmodium falciparum)
    - RA biosynthesis pathway (Plasmodium falciparum)
      - RDH13 reduces atRAL to atROL (Plasmodium falciparum)
        
        H+ [mitochondrial intermembrane space]

Cellular responses to external stimuli (Rattus norvegicus)

- Cellular responses to stress (Rattus norvegicus)
  - Detoxification of Reactive Oxygen Species (Rattus norvegicus)
    - SOD1 catalyzes 2H+ + O2.- => O2 + H2O2 (mitochondrial intermembrane space) (Rattus norvegicus)
      - H+ [mitochondrial intermembrane space]

Gene expression (Transcription) (Rattus norvegicus)

- RNA Polymerase II Transcription (Rattus norvegicus)
  - Generic Transcription Pathway (Rattus norvegicus)
    - Transcriptional Regulation by TP53 (Rattus norvegicus)
      - TP53 Regulates Metabolic Genes (Rattus norvegicus)
        
        Electron transfer from reduced cytochrome c to molecular oxygen (Rattus norvegicus)
        
        H+ [mitochondrial intermembrane space]

Metabolism (Rattus norvegicus)

- The citric acid (TCA) cycle and respiratory electron transport (Rattus norvegicus)
  - Respiratory electron transport, ATP synthesis by chemiosmotic coupling, and heat production by uncoupling proteins. (Rattus norvegicus)
    - Formation of ATP by chemiosmotic coupling (Rattus norvegicus)
      - Enzyme-bound ATP is released (Rattus norvegicus)
        
        H+ [mitochondrial intermembrane space]
    - Mitochondrial Uncoupling (Rattus norvegicus)
      - The proton buffering model (Rattus norvegicus)
        
        Protons are translocated from the intermembrane space to the matrix (Rattus norvegicus)
        
        H+ [mitochondrial intermembrane space]
    - Respiratory electron transport (Rattus norvegicus)

Signal Transduction (Rattus norvegicus)

- Signaling by Nuclear Receptors (Rattus norvegicus)
  - Signaling by Retinoic Acid (Rattus norvegicus)
    - RA biosynthesis pathway (Rattus norvegicus)
      - RDH13 reduces atRAL to atROL (Rattus norvegicus)
        
        H+ [mitochondrial intermembrane space]

Transport of small molecules (Rattus norvegicus)

- Ion channel transport (Rattus norvegicus)
  - Stimuli-sensing channels (Rattus norvegicus)
    - SLC9B2 exchanges Na+, Li+ for H+ (Rattus norvegicus)
      - H+ [mitochondrial intermembrane space]

Cellular responses to external stimuli (Saccharomyces cerevisiae)

- Cellular responses to stress (Saccharomyces cerevisiae)
  - Detoxification of Reactive Oxygen Species (Saccharomyces cerevisiae)
    - SOD1 catalyzes 2H+ + O2.- => O2 + H2O2 (mitochondrial intermembrane space) (Saccharomyces cerevisiae)
      - H+ [mitochondrial intermembrane space]

Metabolism (Saccharomyces cerevisiae)

- The citric acid (TCA) cycle and respiratory electron transport (Saccharomyces cerevisiae)
  - Respiratory electron transport, ATP synthesis by chemiosmotic coupling, and heat production by uncoupling proteins. (Saccharomyces cerevisiae)
    - Formation of ATP by chemiosmotic coupling (Saccharomyces cerevisiae)
      - Enzyme-bound ATP is released (Saccharomyces cerevisiae)
        
        H+ [mitochondrial intermembrane space]
    - Mitochondrial Uncoupling (Saccharomyces cerevisiae)
      - The proton buffering model (Saccharomyces cerevisiae)
        
        Protons are translocated from the intermembrane space to the matrix (Saccharomyces cerevisiae)
        
        H+ [mitochondrial intermembrane space]
    - Respiratory electron transport (Saccharomyces cerevisiae)
      - Electron transfer from ubiquinol to cytochrome c of complex III (Saccharomyces cerevisiae)
        
        H+ [mitochondrial intermembrane space]

Cellular responses to external stimuli (Schizosaccharomyces pombe)

- Cellular responses to stress (Schizosaccharomyces pombe)
  - Detoxification of Reactive Oxygen Species (Schizosaccharomyces pombe)
    - SOD1 catalyzes 2H+ + O2.- => O2 + H2O2 (mitochondrial intermembrane space) (Schizosaccharomyces pombe)
      - H+ [mitochondrial intermembrane space]

Metabolism (Schizosaccharomyces pombe)

- The citric acid (TCA) cycle and respiratory electron transport (Schizosaccharomyces pombe)
  - Respiratory electron transport, ATP synthesis by chemiosmotic coupling, and heat production by uncoupling proteins. (Schizosaccharomyces pombe)
    - Formation of ATP by chemiosmotic coupling (Schizosaccharomyces pombe)
      - Enzyme-bound ATP is released (Schizosaccharomyces pombe)
        
        H+ [mitochondrial intermembrane space]
    - Respiratory electron transport (Schizosaccharomyces pombe)
      - Electron transfer from ubiquinol to cytochrome c of complex III (Schizosaccharomyces pombe)
        
        H+ [mitochondrial intermembrane space]

Cellular responses to external stimuli (Sus scrofa)

- Cellular responses to stress (Sus scrofa)
  - Detoxification of Reactive Oxygen Species (Sus scrofa)
    - SOD1 catalyzes 2H+ + O2.- => O2 + H2O2 (mitochondrial intermembrane space) (Sus scrofa)
      - H+ [mitochondrial intermembrane space]

Gene expression (Transcription) (Sus scrofa)

- RNA Polymerase II Transcription (Sus scrofa)
  - Generic Transcription Pathway (Sus scrofa)
    - Transcriptional Regulation by TP53 (Sus scrofa)
      - TP53 Regulates Metabolic Genes (Sus scrofa)
        
        Electron transfer from reduced cytochrome c to molecular oxygen (Sus scrofa)
        
        H+ [mitochondrial intermembrane space]

Metabolism (Sus scrofa)

- The citric acid (TCA) cycle and respiratory electron transport (Sus scrofa)
  - Respiratory electron transport, ATP synthesis by chemiosmotic coupling, and heat production by uncoupling proteins. (Sus scrofa)
    - Formation of ATP by chemiosmotic coupling (Sus scrofa)
      - Enzyme-bound ATP is released (Sus scrofa)
        
        H+ [mitochondrial intermembrane space]
    - Mitochondrial Uncoupling (Sus scrofa)
      - The proton buffering model (Sus scrofa)
        
        Protons are translocated from the intermembrane space to the matrix (Sus scrofa)
        
        H+ [mitochondrial intermembrane space]
    - Respiratory electron transport (Sus scrofa)

Signal Transduction (Sus scrofa)

- Signaling by Nuclear Receptors (Sus scrofa)
  - Signaling by Retinoic Acid (Sus scrofa)
    - RA biosynthesis pathway (Sus scrofa)
      - RDH13 reduces atRAL to atROL (Sus scrofa)
        
        H+ [mitochondrial intermembrane space]

Transport of small molecules (Sus scrofa)

- Ion channel transport (Sus scrofa)
  - Stimuli-sensing channels (Sus scrofa)
    - SLC9B2 exchanges Na+, Li+ for H+ (Sus scrofa)
      - H+ [mitochondrial intermembrane space]

Cellular responses to external stimuli (Xenopus tropicalis)

- Cellular responses to stress (Xenopus tropicalis)
  - Detoxification of Reactive Oxygen Species (Xenopus tropicalis)
    - SOD1 catalyzes 2H+ + O2.- => O2 + H2O2 (mitochondrial intermembrane space) (Xenopus tropicalis)
      - H+ [mitochondrial intermembrane space]

Gene expression (Transcription) (Xenopus tropicalis)

- RNA Polymerase II Transcription (Xenopus tropicalis)
  - Generic Transcription Pathway (Xenopus tropicalis)
    - Transcriptional Regulation by TP53 (Xenopus tropicalis)
      - TP53 Regulates Metabolic Genes (Xenopus tropicalis)
        
        Electron transfer from reduced cytochrome c to molecular oxygen (Xenopus tropicalis)
        
        H+ [mitochondrial intermembrane space]

Metabolism (Xenopus tropicalis)

- The citric acid (TCA) cycle and respiratory electron transport (Xenopus tropicalis)
  - Respiratory electron transport, ATP synthesis by chemiosmotic coupling, and heat production by uncoupling proteins. (Xenopus tropicalis)
    - Formation of ATP by chemiosmotic coupling (Xenopus tropicalis)
      - Enzyme-bound ATP is released (Xenopus tropicalis)
        
        H+ [mitochondrial intermembrane space]
    - Mitochondrial Uncoupling (Xenopus tropicalis)
      - The proton buffering model (Xenopus tropicalis)
        
        Protons are translocated from the intermembrane space to the matrix (Xenopus tropicalis)
        
        H+ [mitochondrial intermembrane space]
    - Respiratory electron transport (Xenopus tropicalis)
      - Complex I oxidises NADH to NAD+, reduces CoQ to QH2 (Xenopus tropicalis)
        
        H+ [mitochondrial intermembrane space]
      - Electron transfer from reduced cytochrome c to molecular oxygen (Xenopus tropicalis)
        
        H+ [mitochondrial intermembrane space]

Signal Transduction (Xenopus tropicalis)

- Signaling by Nuclear Receptors (Xenopus tropicalis)
  - Signaling by Retinoic Acid (Xenopus tropicalis)
    - RA biosynthesis pathway (Xenopus tropicalis)
      - RDH13 reduces atRAL to atROL (Xenopus tropicalis)
        
        H+ [mitochondrial intermembrane space]

Transport of small molecules (Xenopus tropicalis)

- Ion channel transport (Xenopus tropicalis)
  - Stimuli-sensing channels (Xenopus tropicalis)
    - SLC9B2 exchanges Na+, Li+ for H+ (Xenopus tropicalis)
      - H+ [mitochondrial intermembrane space]