8100321
Description
Flashcards by Megan Ching, updated more than 1 year ago
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Created by Megan Ching
about 7 years ago
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| Question | Answer |
| Where does glycolysis, Link reaction, Krebs cycle and Oxidative Phosphorylation occur? | Glycolysis: Cytosol Link reaction: Mitochondrial matrix Krebs cycle: Mitochondrial matrix Oxidative Phosphorylation: Inner Mitochondrial membrane |
| What is the difference between Lactate and Alcoholic fementation? | |
| What is the difference between aerobic and anaerobic respiration? | |
| What is the product of glycolysis from a glucose molecule? | 2 pyruvate molecules |
| What is the net gain of ATP from gylcolysis and from which step? | 2 ATP molecules; Substrate level phosphorylation |
| How many NADH molecules produced from glycolysis? What is the process called? | 2 NAD+ forms 2 NADH. Dehydrogenation |
| Link reaction and krebs cycle occurs in aerobic/anaerobic respiration? | Aerobic only |
| How does pyruvate enter the mitochondrial matrix? | By active transport via transport orotein |
| What is the name of the reaction that pyruvate undergo to form acetyl CoA? | Oxidative Decarboxylation |
| What does decarboxylation of pyruvate form? | CO2 |
| Why do oxidation occur in link reaction (oxidative carboxylation)? | H atoms are removed and transferred to NAD+ to form NADH |
| What does the remaining 2 carbon fragment of pyruvate do? | Reacts with enzyme CoA to form acetyl CoA |
| Enzyme used in link reaction? | Pyruvate dehydrogenase |
| products formed from link reaction? (per glucose molecule) | •2 NADH(for o.p.) •2 acetyl CoA (for krebs cycle) •2 CO2 (exhaled frm lungs) |
| product formed from glycolysis? | •2 pyruvate molecules (for link rxn) •2 NADH (for o.p.) •2 ATP (net gain) |
| What reaction does acetyl CoA undergo during krebs cycle? | Oxidative carboxylation |
| What is the name of the molecule that is regenerated in krebs cycle? | Oxaloacetate |
| Product formed during Krebs cycle | •Oxaloacetate (regenerated for krebs cycle) •6 NADH (for o.p.) •2 FADH2 (for o.p.) •2 ATP (formes from substrate level phosphorylation) •4 CO2 (exhaled frm lungs) |
| Draw the 'diagram-to-go' for Glycolyis till Krebs cycle | |
| If 2 acetyl CoA are fed into Krebs cycle, how many ATP will be synthesised in the cycle? | 2 |
| if 2 acetyl CoA molecules are fed into krebs cycle, how many NADH molecules produced? | 6 |
| What happens to FADH2 and NADH in oxidative phosphorylation? | NADH and FADH2 will transfer its electrons to a series of electron carriers in the Electron Transport Chain (ETC) located in the inner mitochondrial membrane. |
| What are the 2 special features of the electron carriers in the ETC? | 1. Each electron carrier has the ability to be oxidised and reduced. 2. Some electron carriers act as a proton pump to pump H+ ions from the mitochondrial matrix into the intermembrane space. |
| What will NADH and FADH2 form after losing its electrons to the ETC? | They will regenerate NAD+ and FAD respectively |
| What happens to the H atoms during Oxidative Phosphorylation? | H atoms will split into its constituent H+ ions and electrons |
| What happens to the electrons and H+ ions during oxidative phosphorylation? | Electron is transferred to the series of electron carriers while H+ ions remain in solution in the mitochondrial matrix |
| How are the electrons passed down during oxidative phosphorylation? | They are passed down the series of electron carriers with increasing electronegativity and decreasing energy levels. |
| When will the electron stop passing down the ETC? | Until it reaches the final electron acceptor, O2, (which has the highest electrinegativity and the greatest affinity for electrons) and recombines with electrons and H+ ions to form water |
| Enzyme that catalyses oxidative phosphorylation | cytochrome oxidase (found in inner mitochondrial membrane) |
| What is the energy released during the movement of electron in oxidative phosphorylation used for? | Used to pump H+ ions from the mitochondrial matrix to the intermembrane space via active transport and a proton gradient is generated |
| What happens during chemiosmosis? | H+ ions move from the intermembrane space to the mitochondrial matrix down a concentration gradient via ATP synthase |
| What does the ATP synthase consists of location and functions of the different parts? | 1. Hydrophilic protein channels, F0 proteins; embedded in the inner mitochondrial membrane; allows the diffusion of H+ ions 2. Enzymatic domain (ATP synthase), called F1 protein; located at the tip; catalysis the synthesis of ATP from ADP and Pi |
| What is the electrochemical 'force' that drives ATP called? | Proton-motive force |
| What is the function of oxidative phosphorylation? | 1. Produces ATP 2. Regenerates FAD and NAD+ for use in glyolysis,link reaction and krebs cycle |
| What is the total number of ATP molecules priduced as a result of complete oxidation of a glucose molecule? | 32 ATP 10 NADH 2 FADH2 |
| Draw the Diagram-to-go for oxidative phosphorylation | |
| How many molecules of ATP produced from Oxidatuve Phosphorylation? | 28 |
| What happens during anaerobic respiration? (4 points) | 1. O2 no longer available as the final electron acceptor 2. Co-enzymes remain reduced (FADH2 and NADH) 3. No regeneration of FAD and NAD+ 4. Link reaction, Krebs cycle and oxidative phosphorylation stopped |
| Will there still be ATP synthesised? If yes, how many and when will it be synthesised? | 2 ATP produced when glucose oxidised during glycolysis via substrate level phosphorylation |
| Why would oxidative phosphorylation be blocked during anaerobic respiration? | Due to O2 not available to be the final electron acceptor, NADH and FADH2 will not transfer their H atoms to the electron transport chain (ETC) and no electrons donated, therefore: • No electrons transferred along the series of electron carriers • No energy released to pump H+ ions from the mitochondrial matrix accross the inner mitochondrial membrane into the intermembrane space. •No diffusion of H+ from the inter membrane space back into the mitochondrial matrix via F0 protein • Hence no synthesis of ATP from ADP and Pi via ATP synthase |
| Why would Krebs cycle and Link reaction be blocked during anaerobic respiration? | • Under anaerobic conditions, no 02 to be the final electron acceptor, no FADH2 and NADH will transfer its H atoms to the Electron Transport Chain (ETC) hence no electrons donated. • Therefore no regeneration of FAD and NAD+ for link reaction and Krebs cycle. |
| If there is no regeneration of FAD and NAD+, why is glycolysis not blocked too since it requires NAD+? | •Cells undergo fermentation to regenerate NAD+ (i) Lactate fermentation in animals (ii) Alcoholic fermentation in plants • Both fermentation iccur in the cytosol and do not oroduce any ATP, but only regenerate NAD+by transferring electrons to pyruvate • This prevents the cell from depleting the pool of NAD+, which is the oxidising agent necessary for glycolysis to continue. • Hence ATP can still be produced in smaller amounts in absence of O2. |
| Does fermentation produce any ATP? | No |
| What type of fermentation occur in animals and plants? | Lactate and Alcoholic respectively |
| What does fermentation regenerate? | NAD+ |
| What is the significance of lactate fermentation? | Pyruvate is reduced by NADH to form lactate and NAD+ is regenerated. When aerobic conditions resume, lactate will be transported to the liver and reconverted into pyruvate. Pyruvate then converted into acetyl CoA for link reaction to form CO2 and water or converted into glucose for storage in liver and muscle cells as glycogen. |
| What is the significance of ethanol being produced during aloholic fermentation? | Pyruvate is decarvoxylated to form ethanal with the release of CO2 (Enzyme is pyruvaye decarboxylase) NADH then reduced ethanal to form ethanol and NAD+ is regenerated for use in glycolysis to generate ATP (Enzyme is alcohol dehydrogenase) |
| Who is the hydrogen acceptor in aerobic and anaerobic repiration? | Aerobic: O2 to form H20 Anaerobic: Pyruvate to generate NAD+ |
| What is the yield of Anaerobic respiration? | Animals: 2 ATP and 2 Lactate Plants: 2 ATP, 2 Ethanol and 2 CO2 |
| What are the factors affecting respiration? | 1. Substrate Concentration (Enzyme activity) 2. Type of substrate (simple sugars eg glucose proceed at a higher rate as compared to complex sugar eg Maltose 3. Temperature (Enzyme activity) 4. Amount of Oxygen (Final electron acceptor in o.p.) 5. Amount of water (rate of respiration decreases with decreasing amt of water bc water is needed as a medium fir various reactions) 6. State of cell (young and developing cells undergo higher rate of respiration as compared to dormant cells) |
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