LABORATORY REVIEW
CELL RESPIRATION
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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It attaches and detaches phosphate groups
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It uses stored ATP and then forms a net increase in ATP
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It both splits molecules and assembles molecules
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Detailed explanation-1: -Question 48 Why is glycolysis described as having an investment phase and a ‘payoff phase? It uses stored ATP and then forms net increase in ATP: It shifts molecules from cytosol to mitochondrion It uses glucose and generates pyruvate: It attaches and detaches phosphate groups.
Detailed explanation-2: -Glycolysis is described as having an investment phase and a payoff phase because it must ‘invest’ 2 ATP molecules in order to get a 4 ATP payoff at the end of the pathway.
Detailed explanation-3: -Why is glycolysis described as having an investment phase and a payoff phase? It uses stored ATP and then forms a net increase in ATP. In the presence of oxygen, the three-carbon compound pyruvate can be catabolized in the citric acid cycle.
Detailed explanation-4: -The second half of glycolysis is called the energy payoff phase. In this phase, the cell gains two ATP and two NADH compounds. At the end of this phase, glucose has become partially oxidized to form pyruvate.
Detailed explanation-5: -Step 1: Glucose is phosphorylated by the enzyme hexokinase to form glucose 6-phosphate. Glucose gains energy by being phosphorylated at the expense of one ATP.