Term
| Desrcibe mitochondria structure |
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Definition
| Mitochondria have two membranes because they used to be prokaryotes of their own until endosymbiosis. They multiply through binary fission, further proving their prokaryote origins (like bacteria). Membrane bound proteins to let molecules in and out. Inner membrane with tons fo enzymes and proteins to shuttle electrons. Cristae folding for surface area (structure relates to function, bigger surface area allows for more proteins and as a result, higher efficieny). |
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Term
| Explain pyruvate oxidation. |
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Definition
| Pyruvate oxidation occurs from the cytoplasm to the matrix. Both of the pyruvates go through a transport protein, they lose CO2 (oxidation) and as a result, NAD+ reduces into NADH. Final result is Acetyl-CoA which feeds into Krebs Cycle. Net Yield so far: 2 CO2 exhaled, 2 NADH |
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Term
| What is the CO2 and what is Acetyl-CoA? |
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Definition
| The CO2 exhaled is 1/3 of all the CO2 exhaled by humans in pyruvate oxidation. Acetyl-CoA is a 2 carbon molecule that is attached to sulfur, not carbon directly. (Pyruvate was too big, needed transport protein) |
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Term
| What is Krebs Cycle on an evolutionary basis? |
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Definition
| AKA Citric Acid Cycle, it is an 8 step process. It evolved later than glycolysis because it happens in the matrix of the mitochondria (which are in eukaryotes, while glycolysis was prokaryotes). Makes sense because prokaryotes -> Free O2 -> eukaryotes (aerobic respiration = organelles -> mitochondria) |
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Term
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Definition
| It is a ferris wheel. Acetyl-CoA enters the wheel, binds to oxaloacetate to make citrate. H2O and CO2 leave. NADH, ATP and FADH2 form along the way. STEP 5: special step where GDP turns into GTP (endergonic) using energy from substrates, and then it turns back into GDP (exergonic) to give ADP energy to become ATP (endergonic). Each pyruvate (there are two) go through this process. |
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Term
| What is the value of Krebs Cycle if same amount of ATP is made in glycolysis? |
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Definition
| Net Yield: 2 ATP, 8 NADH and 2 FADH2. Its value is not production of ATP, it is that it makes lots of valuable elctron carriers to helps produce an extremely large amount of ATP in electron transport chain. |
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Term
| How is Krebs Cycle Thermodynamically favoured? |
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Definition
| 1. 1st law with energy conserved, never created or destroyed, only converted. Krebs has creation of NADH and FADH2 which reduced (took energy) and will give it back in other reactions later) 2. 2nd law is chaos in universe because it makes smaller molecules from bigger ones (from 6C citrate, to C4) |
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Term
| Explain the method of creating ATP known as substrate-level phosphorylation. |
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Definition
| SUbstrate-level phosphorylation is anaerobic and it occurs in glycolysis and in Krebs Cycle. ATp generated directly in a enzyme- catalyzed reaction. Phosphate containting substrate enters an enzyme along with ADP, P gets transfered over to ADP to form ATP. Endergonic reaction that happens quicker sometimes when closer together. |
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Term
| Explain the method of generating ATP: Chemiosmosis |
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Definition
| Movement of H+ ions through ATP synthase. It is the diffusion of protons across a concentration gradient to increase in entropy. It is chemical osmosis and there is a release of energy by the diffusion process to generate ATP. |
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Term
| How does Chemiosmosis support the two laws? |
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Definition
| 1st law: energy is captured by ADP to make ATP from the released electron/H+ energy. 2nd law: energy is being released and bigger molecules become smaller ones (chaos in the universe). |
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Term
| What is the purpose of oxidative phophorylation and what is it? |
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Definition
| 3 main functions: 1. Generate a lot of ATP 2. Recycle NAD+ and FAD into glycolysis and 3. Remove dangerous free radicals like Oxygen as to not harm other cells or organelles. This is a type of chemiosmosis and it occurs in the inner membrane (lots of proteins due to high surface area) of the mitochondria. Generates a lot more ATP in aerobic respiration and now oxidizes electron carriers to make ATP instead of making them. |
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Term
| Step-by-step explanation of Electron Transport Chain. |
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Definition
| 1. Oxygen's electronegativity cuases NADH and FADH2 to break down. 2. NADH oxidizes and sends off 2 electrons to the first proton pump and hydrogen through the proton pump. 3. H+ is pumped out into the intermembrane space and the elctrons are carried over by the shuttle molecule: ubiquinone. 4. Ubiquinone carries the electrons over to the next proton pump where more H+ are pumped out to intermembrane space thanks to FADH2 breakdown. 5. Cytochrome-C shuttle molecule now carries over to final proton pump. 6. Reminaing protons pumped out and H2O is formed with Oxygen (no longer a free radical). 7. Proton gradient sends H+ ions through ATP synthase to combine ADP and Pi with the help of H2O |
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Term
| What is the worth of each molecule? |
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Definition
| Proton pumps are proteins! NADH offers 3 ATP per molecule. FADH2 offers 2 ATP per molecule (because it only passes through 2 proton pumps). |
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Term
| Thermodynamics for Cell resp. |
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Definition
| 1st Law: energy conserved and converted between ATP, NADH and FADH2 2nd Law: release of thermal energy to cause chaos and larger to smaller molecules |
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