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| Cellular Respiration (equation) |
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Definition
| C6H12O2 + 6 O2 6 CO2 + 6 H2O + Heat |
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Term
| How is the equation of cellular respiration related to the one for photosynthesis? |
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Definition
| The products of cellular respiration are the reactants for photosynthesis |
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Term
| Why is ATP an excellent energy storage molecule for the cell? |
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Definition
-it has such high potential energy
-ATP is unstable and is not stored
-The production and use of ATP is fast
-ATP has high potential energy and allows cells to overcome life's energy barriers |
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Term
| How can the breakdown of ATP be used to drive an endergonic reaction? Explain the role of phosphorylation in this process. |
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Definition
| When a phosphate group from ATP is added (phosphorylation) is added to one or both of the reactant molecules, the potential energy of the reactant is increased. This phosphorylated intermediate is referred to as an activated substrate. This is the critical point: Activated substrates have high enough potential energy that the reaction between compound A and, for example, the activated form of compound B is now exergonic. The two compounds then go to react and form the product molecule AB (endergonic reaction). |
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Term
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Definition
| chemical reactions that involve the loss or gain of one or more electrons |
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Term
| Glucose is slowly oxidized (over 10 steps) to produce.... |
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Definition
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Term
| What happens to the electrons that removed during the oxidation of glucose during glycolysis? |
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Definition
Electron carriers take them
ex NAD+ to become NADH |
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| When glucose is broken during glycolysis results in the production of ___ net ATP |
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Definition
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Term
| T/F: Oxygen is required for glycolysis |
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Definition
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Term
| Glycolysis occurs in the.... |
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Definition
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Term
| If O2 IS PRESENT, pyruvate enters the matrix of the mitochondrion and undergoes... |
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Definition
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Term
| If O2, IS ABSENT, pyruvate stays in the cytosol and is used in a process called.... |
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Definition
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Term
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Definition
| a metabolic pathway that regenerates NAD+ by oxidizing stockpiles of NADH; the electrons from NADH are transferred to pyruvate, or a molecule derived from pyruvate, instead of an electron transport chain |
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Term
| Fermentation occurs in the... |
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Definition
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Term
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Definition
| pyruvate is reduced to lactate (lactic acid) |
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Term
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Definition
| pyruvate is reduced in two steps to form ethanol and carbon dioxide |
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Term
| What are the phases of cellular respiration? How many molecules of ATP are produced in each phase? |
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Definition
Glycolysis: 2 net ATP
Pyruvate processing: 0 ATP
Citric Acid Cycle: 2 ATP
Electron Transport Chain: 25 ATP (far more than the others) |
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Term
| What are the major products of the citric acid cycle? |
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Definition
-Oxaloacetate (needed for the citric acid cycle to keep going)
-2 ATP
-NADH and FADH2(needed for the ETC)
-CO2 |
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Term
| The citric acid cycle occurs in.... |
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Definition
| the matrix of the mitochondrion |
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Term
| What property of the electron carriers in the electron chain causes the electrons to be passed from one electron carrier to another electron carrier? Is this process endergonic or exergonic? Explain |
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Definition
| They are of increasing electronegativity, and it is exergonic because energy is released and it is a downhill reaction |
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Term
| ___________ is the last acceptor in the electron transport chain because it has the highest electronegativity of all the carriers |
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Definition
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Term
| During the electron transport chain, protons are transported against the concentration gradient from the _________ to the ___________ _______ |
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Definition
| Matrix; intermembrane space |
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Term
| T/F: The source of energy that drives active transport of protons is from the energy produced from the beginning of the ETC |
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Definition
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Term
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Definition
| the gradient of protons produced during the electron transport chain |
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Term
| ATP synthase is found in... |
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Definition
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Term
| Describe how ATP synthase works |
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Definition
| ATP synthase has two major components, designated Fo and F1, connected by a shaft. The Fo unit spins as protons pass through. The shaft transmits the rotation to the F1 unit, causing it to make ATP from ADP and Pi. It works like a motor |
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Term
| The electron transport chain occurs in... |
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Definition
| the inner membrane of the mitochondrion |
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Term
| Besides glucose, are other types of food molecules used for cellular respiration? Explain. |
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Definition
| Yes, we can break those other foods down to where they are intermediates or specifically glucose, pyruvate, acetyl CoA to continue in the cellular respiration process |
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Term
| Where does the citric acid cycle occur in eukaryotes? |
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Definition
| In the matrix of mitochondria |
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Term
| After glucose is fully oxidized by glycolysis, pyruvate processing, and the citric acid cycle, where is most of the energy stored? |
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Definition
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Term
| What is the function of the reactions in a fermentation pathway? |
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Definition
| To generate NAD+ from NADH, so glycolysis can continue |
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Term
| Which of the following would cause cells to switch from cellular respiration to fermentation? |
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Definition
| The final electron acceptor in the ETC is not available |
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Term
| Describe the relationship between carbohydrate metabolism, the catabolism of proteins and fats, and anabolic pathways. |
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Definition
| Stored carbohydrates can be broken down into glucose that enters the glycolytic pathway. If carbohydrates are absent, products from fat and protein catabolism can be used to fuel cellular respiration or fermentation. If ATP is plentiful, anabolic reactions use intermediates of the glycolytic pathway and the citric acid cycle to synthesize carbohydrates, fats, and proteins |
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Term
| If you were to expose cells that are undergoing cellular respiration to a radioactive oxygen isotope in the form of O2, which of the following molecules would you expect to be radiolabeled? |
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Definition
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| Explain the relationship between electron transport and oxidative phosphorylation. What does ATP synthase look like, and how does it work? |
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Definition
| Oxidative phosphorylation is possible via a proton gradient that is established by redox reactions in the ETC. ATP synthase consists of a membrane associated Fo unit, it spins the rotor shaft within the fixed F1 unit. This spinning shaft causes structural changes in the F1 that drives the synthesis of ATP from ADP and Pi. |
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Term
| Cyanide (C-triple bonded-N(minus 1 charge)) blocks complex IV of the electron transport chain. Suggest a hypothesis for what happens to the ETC when complex IV stops working. Your hypothesis should explain why cyanide poisoning in humans is fatal. |
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Definition
| When complex IV is blocked, electrons can no longer be transferred to oxygen, the final acceptor, and cellular respiration stops. Fermentation could keep glycolysis going, but it is inefficient and unlikely to fuel a cell’s energy needs over the long term. Cells that lack the enzymes required for fermentation would die first |
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Term
| The presence of many sac-like cristae results in a large amount of membrane inside mitochondria. Suppose that some mitochondria had few cristae. How would their output of ATP compare with that of mitochondria with many cristae? |
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Definition
| Because mitochondria with few cristae would have fewer electron transport chains and ATP synthase molecules, they would produce much less ATP than mitochondria with numerous cristae |
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Term
| Suppose a drug were added to mitochondria that allowed protons to freely pass through the inner membrane. Which of the following mitochondrial activities would most likely to be inhibited? |
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Definition
| Oxidative phosphorylation |
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