Biochemistry Multiple Choice Questions on “Phosphoryl Group Transfers and ATP”.
1. Anabolism and catabolism are chemically linked in the form of __________
A. ADP
B. ATP
C. Phosphodiester linkage
D. ASP
Answer: B
Clarification: Anabolism is an energy intake process where small molecules build upto large molecules whereas catabolism involves the release of energy where large molecules tear down to smaller molecules.
2. Which of the following statements is false about ATP hydrolysis?
A. It is highly exergonic
B. Activation energy is relatively high
C. ∆G‘°=-30.5kJ/mol
D. ∆G‘°=30.5kJ/mol
Answer: D
Clarification: ∆G‘° should be negative for an exergonic process.
3. An endergonic reaction ____________
A. Proceeds spontaneously
B. Does not require activation energy
C. Releases energy
D. Requires energy
Answer: D
Clarification: Endergonic reaction involves intake of energy.
4. An exergonic reaction ____________
A. Proceeds spontaneously
B. Does not require activation energy
C. Releases energy
D. Requires energy
Answer: C
Clarification: Exergonic reaction involves release of energy.
5. Phosphoryl groups are derivatives of ____________
A. Phosphorous acid
B. Phosphoric acid
C. Acetic acid
D. Citric acid
Answer: B
Clarification: Phosphoryl groups are derivatives of phosphoric acid.
6. Water does a nucleophilic attack on phosphate monoester by producing ____________
A. Phosphorous chloride
B. Phosphorous sulfide
C. Inorganic phosphate
D. Organic phosphate
Answer: C
Clarification: Inorganic phosphate is produced when a nucleophilic attack is done by water on phosphate monoester.
7. The phosphate groups used during glycolysis are ____________
A. Organic
B. Inorganic
C. Neutral
D. None
Answer: B
Clarification: Phosphorous can only be produced from inorganic phosphate.
8. Which of the following is false about acetyl-coA?
A. It is a thioester
B. It has a large, negative standard free energy of hydrolysis
C. It contains phosphorous atom in the position occupied by an oxygen atom in oxygen esters
D. It contains a sulfur atom in the position occupied by an oxygen tom in oxygen esters
Answer: C
Clarification: Acetyl-coA is a thioester containing phosphorous atom in the position occupied by an oxygen atom in oxygen esters.
9. Which is an example of chemical to osmotic energy conversion that occurs in living organisms?
A. ATP-driven muscle contraction
B. ATP-dependent photon emission in fireflies
C. light-induced electron flow in chloroplasts
D. ATP-driven active transport across a membrane
Answer: D
Clarification: ATP-driven muscle contraction is an example for chemical to mechanical energy conversion.
ATP-dependent photon emission in fireflies is an example for chemical to electromagnetic energy conversion.
Light-induced electron flow in chloroplasts is an example for electromagnetic to electrical energy conversion.
10. Which is an example of chemical to electromagnetic energy conversion that occurs in living organisms?
A. ATP-driven muscle contraction
B. ATP-dependent photon emission in fireflies
C. light-induced electron flow in chloroplasts
D. ATP-driven active transport across a membrane
Answer: B
Clarification: ATP-driven muscle contraction is an example for chemical to mechanical energy conversion.
Light-induced electron flow in chloroplasts is an example for electromagnetic to electrical energy conversion.
ATP-driven active transport across a membrane is an example for chemical to osmotic energy conversion.
11. Which is an example of chemical to mechanical energy conversion that occurs in living organisms?
A. ATP-driven muscle contraction
B. ATP-dependent photon emission in fireflies
C. light-induced electron flow in chloroplasts
D. ATP-driven active transport across a membrane
Answer: A
Clarification: ATP-dependent photon emission in fireflies is an example for chemical to electromagnetic energy conversion.
Light-induced electron flow in chloroplasts is an example for electromagnetic to electrical energy conversion.
ATP-driven active transport across a membrane is an example for chemical to osmotic energy conversion.
12. Which is an example of electromagnetic to electrical energy conversion that occurs in living organisms?
A. ATP-driven muscle contraction
B. ATP-dependent photon emission in fireflies
C. light-induced electron flow in chloroplasts
D. ATP-driven active transport across a membrane
Answer: C
Clarification: ATP-driven muscle contraction is an example for chemical to mechanical energy conversion.
ATP-dependent photon emission in fireflies is an example for chemical to electromagnetic energy conversion.
ATP-driven active transport across a membrane is an example for chemical to osmotic energy conversion.
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