Multiple Choice QuestionsDuring which stage in the complete oxidation of glucose are the greatest number of ATP molecules formed from ADP?
Conversion of pyruvic acid to acetyl Co-A
Electron transport chain
Glycolysis
Krebs cycle
B.
Electron transport chain
In glycolysis, 4 ATP and 2 NADH2 molecules are formed. These 2 NADH2 molecules go to electron transport chain.
In oxidative decarboxylation no ATP molecules are formed but two molecules of NADH2 are formed from two molecules of pyruvate. And both NADH2 molecules go to ETC (Electron Transport Chain).
In Krebs cycle 2 ATP, 6NADH2 and 2FADH2 molecules are formed from two molecule of acetyl Co-A. These NADH2 and FADH2 go to ETC.
In ETC all NADH2 and FADH2 pass to electron carriers and yield 3 ATP and 2 ATP molecules per NADH2 and FADH2 respectively. Thus,
4 ATP are formed in glycolysis
2 ATP in Krebs cycle and
34 ATP from electron transport chain
40 ATP
2 ATP molecules are used during glycolysis.
So, net gain of ATP molecules during one complete oxidation of a glucose molecule is 38 ATP.
Chemiosmotic theory of ATP synthesis in the chloroplasts and mitochondria is based on
proton gradient
accumulation of K ions
accumulation of Na ions
membrane potential
The terminal electron acceptor during electron transport system is
oxygen
cyto a3
cyto c
plasto quinone
Assertion: Conversion of 1,3 biphosphoglycerate (BPGA) to 3-phospho-glyceric acid (PGA) is an energy yielding step.
Reason: This energy is trapped in the form of ATP
If both assertion and reason are true and reason is the correct explanation of assertion.
If both assertion and reason are true but reason is not the correct explanation of assertion.
If assertion is true but reason is false.
If both assertion and reason are false.
Which enzyme helps in transfer of phosphate group from ATP to a carbohydrate
Phosphatase
ATPase
Phosphorylase
Catalase
Assertion: Glucose is the favoured respiratory substrate.
Reason: When glucose is used as respiratory substrate and is completely oxidized, the RQ is 1.
If both assertion and reason are true and reason is the correct explanation of assertion.
If both assertion and reason are true but reason is not the correct explanation of assertion.
If assertion is true but reason is false.
If both assertion and reason are false.
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