TCA Cycle MCQs : This section focuses on the "TCA Cycle". These Multiple Choice Questions (MCQs) should be practiced to improve the TCA Cycle skills required for various interviews (campus interview, walk-in interview, company interview), placement, entrance exam and other competitive examinations.
Question 1
How many reactions that occur in the TCA cycle transfer electrons from a substrate to an electron accepting enzyme?
A. 1
B. 2
C. 3
D. 4
Question 2
In eukaryotes, electron transport occurs in
A. membranes and mitochondria
B. endoplasmic reticulum
C. cytoplasm
D. all of the above
Question 3
Oxidation of a molecule involves
A. gain of electron
B. loss of electron
C. gain of proton
D. loss of proton
Question 4
Important function of cholesterol is to
A. modulate fluidity
B. enhance blood circulation
C. prevent bile salts formation
D. None of these
Question 5
Malate-asparatate shuttle operates in
A. lungs and liver
B. heart and liver
C. pancreas and liver
D. none of these
Question 6
Most of the enzymes of the citric acid cycle in a eukaryotic cell are located in the
A. inner mitochondrial membrane
B. cytosol
C. mitochondrial matrix
D. intermembrane space
Question 7
Which one of the following is not the intermediate of Kreb's cycle?
A. Isocitrate
B. Succinate
C. Fumarate
D. Stearate
Question 8
The end product of glycolysis is pyruvate, which enters the citric acid cycle after being converted to
A. acetic acid
B. acetyl-CoA
C. acetaldehyde
D. none of these
Question 9
How many ATPs are produced during citric acid cycle?
A. 10
B. 13
C. 12
D. 8
Question 10
How many molecules of ATPs are synthesized per NADH oxidation?
A. 2
B. 1
C. 3
D. 4
Question 11
To stop ATP synthesis which chemical is generally used?
A. DNSA
B. 2,4 dinitrophenol
C. DDT
D. None of the chemical can stop ATP synthesis
Question 12
Which of the following is also known as Krebs cycle?
A. Electron transport chain
B. Glycolysis
C. TCA cycle
D. DNA Replication
Question 13
The enzymes of the TCA cycle in a eukaryotic cell are located in the
A. nucleus
B. mitochondria
C. plasma membrane
D. lysosomal bodies
Question 14
Standard redox potential for a substance is measured under standard condition and is expressed as
A. mili-Ampere
B. Volt
C. without unit
D. Ohm
Question 15
Which of the following is an important end product of disassembly of fatty acids?
A. Acetyl CoA
B. Succinate dehydrogenase
C. Pyruvate
D. DNA gyrase
Question 16
The FADH2 and NADH produced by the oxidation of one acetyl-CoA results in the synthesis of about-
A. 3 ATPs
B. 6 ATPs
C. 11 ATPs
D. 15 ATPs
Question 17
The first intermediate in TCA cycle is
A. succinate
B. fumerate
C. citrate
D. malate
Question 18
For each molecule of glucose, how many times does the TCA cycle proceed?
A. 1
B. 2
C. 3
D. 4
Question 19
Cholesterol can be synthesized de novo in
A. pancreas
B. intestine
C. liver
D. cell membrane
Question 20
In the TCA cycle, which of the following combines with Acetyl CoA to form a 6 carbon compound?
A. oxaloacetate
B. glucose
C. pyruvate
D. thiamine
Question 21
Acetyl CoA is a _____________ carbon compound.
A. 1
B. 2
C. 3
D. 4
Question 22
In what form does the product of glycolysis enter the TCA cycle?
A. AcetylCoA
B. Pyruvate
C. NADH
D. Glucose
Question 23
Why is the TCA cycle the central pathway of metabolism of the cell?
A. It occurs in the center of the cell
B. Its intermediates are commonly used by other metabolic reactions
C. All other metabolic pathways depend upon it
D. None of the above
Question 24
Polysaccharides, fats and proteins break down into metabolites of __________________
A. Glycolysis
B. TCA cycle
C. RNA repair
D. Membrane synthesis
Question 25
Most multi-cellular organisms obtain energy for the synthesis of ATP during oxidative phosphorylation from
A. high energy phosphate compounds
B. a proton gradient across the inner mitochondrial membrane
C. a proton gradient across the cell membrane
D. a proton gradient across the outer mitochondrial membrane
Question 26
Citric acid cycle occurs in
A. cytoplasm
B. mitochondria
C. endoplasmic reticulum
D. golgi bodies
Question 27
Energy that is released from glucose during respiration but not transferred to ATP bonds can be detected as
A. CO2
B. AMP
C. ADP
D. heat
Question 28
Which of the following is involved in energy production?
A. Generation of proton gradients across membranes
B. Transport of electrons on organic molecules
C. Conversion of compounds with high energy to those of low energy
D. All of the above
Question 29
All enzymes of the TCA cycle reside in the mitochondrial membrane.
A. True
B. False
Question 30
The enzyme aconitase is responsible for ________________
A. polymerization
B. degradation
C. assembly
D. isomerization
Question 31
The catabolism of sugars and fatty acids is similar because
A. both of these compounds are funnelled through the TC A/citric acid cycle
B. both of these compounds generate redox energy during catabolism
C. both of these compounds generate chemical energy during catabolism
D. all of the above
Question 32
Which of the following enzyme does not take part in the TCA cycle?
A. Citrate synthase
B. Iso-citrate dehydrogenase
C. Pyruvate dehydrogenase
D. Malate dehydrogenase
Question 33
During cellular respiration, most of the ATP made, is generated by
A. oxidative phosphorylation
B. photophosphorylation
C. glycolysis
D. substrate-level phosphorylation
Question 34
A positive redox potential means substance has
A. lower affinity for electron
B. higher affinity for electron
C. lower affinity for proton
D. higher affinity for proton
Question 35
Which one is not the main protein in electron transport chain?
A. NADH dehydrogenase
B. Cytochrome bc1 complex
C. Cytochrome oxidase
D. Citrate synthease