Term
| The term "substrate level phosphorylation" refers to... |
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Definition
| A metabolic pathway by which ATP is produced directly. Occurs in glycolysis and TCA cycle. Only a small % of energy from glucose oxidation occurs this way. |
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Term
| What drives the electron-motive force? |
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Definition
| Electron pairs from NADH or FAD(2H) reduce O2 --> H2O via a cascade of redox reactions between protein complexes in the inner mitochondrial membrane. |
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Term
| How does the electron-motive force create the proton-motive force? |
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Definition
| As the electron pair from NADH or FAD(2H) cascade down the electron transport chain via redox reactions, protons are pumped from the matrix into the inter-membrane space creating a pH gradient and an electrical potential across the inner mitochondrial membrane. |
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Term
| What is the importance of the impermeable inner membrane of mitochondria? |
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Definition
| The flow of protons from the inner-membrane space into the matrix (down proton gradient) is coupled to ATP synthesis. |
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Term
| What is the importance of the impermeable inner membrane of mitochondria? |
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Definition
| The flow of protons from the inner-membrane space into the matrix (down proton gradient) is coupled to ATP synthesis. |
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Term
| B vitamins associated with electron carriers NADH & FAD(2H) |
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Definition
NADH: niacin (vitamin B3)
FAD(2H): riboflavin (vitamin B2) |
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Term
| Pellagra is a deficiency of what and manifests in what physiological conditions? |
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Definition
| Niacin deficiency. Diarrhea, dermatitis, dementia. |
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Term
| What symptoms accompany riboflavin deficiency? |
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Definition
| Cracks and sores on outside of lips (cheliosis) and dermatitis. |
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Term
| Name the players involved in the electron transport chain. |
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Definition
| Complex I - IV, coenzyme Q, cytochrome c. |
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Term
| Which protein complexes in the respiratory chain are proton pumps? |
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Definition
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Term
| The proteins of the respiratory chain are encoded from what genetic information? |
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Definition
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Term
| FAD(2H) transfers an electron pair to what complex? What are the ramifications? |
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Definition
| Complex II. For every FAD(2H) oxidized, only ~6 protons are pumped into the inner-membrane space. |
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Term
| How is the oxidation of NADH different from that of FAD(2H)? |
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Definition
| NADH transfers its electron pair to Complex I where as FAD(2H) transfers its electron pair to Complex II. NADH oxidation results in ~10 protons pumped into inner-membrane space. FAD(2H) only ~6 protons. |
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Term
| Where is O2 reduced to H2O during oxidative phosphorylation? |
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Definition
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Term
| Poisons that inhibit complex IV |
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Definition
| cyanide, carbon monoxide, azide |
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Term
| If cyanide binds to complex IV and inhibits O2 binding, all up stream protein complexes will remain in what oxidation state? |
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Definition
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Term
| What some reactive oxygen species |
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Definition
| superoxide, hydrogen peroxide and hydroxyl radicals |
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Term
| The most dangerous ROS is... |
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Definition
| hydroxyl radicals which oxide lipids, DNA and proteins. |
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Term
| ROS are produced by collision of O2 and a free electron. What conditions facilitate this to occur? |
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Definition
| When food consumption exceeds caloric needs the proton gradient in mitochondrial inner membrane increases and leads to increased production of ROS. |
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Term
| What are the two roles of cytochrome c? |
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Definition
| Mobile electron carrier in respiratory chain and if mitochodria are damaged due to ROS cytochrome c is released and mitochondria is destroyed. if many mitochondria are destroyed, cytochrome c goes to cytosol and forms apoptosome --> apoptosis. |
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