32 Questions
Which molecule forms first during the citric acid cycle?
Citrate
What is another name for the citric acid cycle due to the three carboxyl groups on its first two intermediates?
Tri-carboxylic acid cycle
Who is the discoverer of the citric acid cycle?
Hans Krebs
Where does the citric acid cycle take place in eukaryotic cells?
Mitochondrial matrix
What is the starting material for the citric acid cycle?
Acetyl CoA
What do the reduced electron carriers NADH and FADH generated in the TCA cycle pass their electrons into?
Electron transport chain
Which molecule combines with oxaloacetate in the first step of the citric acid cycle?
Acetyl CoA
How many carbon dioxide molecules are released in the first two steps of the citric acid cycle?
1
Which enzyme catalyzes the third step of the citric acid cycle?
Isocitrate dehydrogenase
What is the result of the fourth step in the citric acid cycle?
Release of a molecule of carbon dioxide
Which molecule is reduced to form FADH2 in the citric acid cycle?
Isocitrate
How many ATP or GTP molecules are produced per turn of the citric acid cycle?
1
What happens to oxaloacetate at the end of one turn of the citric acid cycle?
It is regenerated to start the cycle again
How many pyruvate molecules are made per glucose in cellular respiration?
$2$
What is the main function of the citric acid cycle in cellular respiration?
Production of ATP and NADH
What is the purpose of the quick rearrangement that occurs after citrate is formed in the first step of the citric acid cycle?
To regenerate oxaloacetate
The citric acid cycle is also known as the TCA cycle, which stands for tri-carboxylic acid cycle.
True
The citric acid cycle occurs in the cytoplasm of eukaryotic cells.
False
The primary starting material for the citric acid cycle is acetyl CoA, which is derived from the oxidation of glucose.
True
The citric acid cycle harvests most of its bond energy in the form of NADH, FADH, and ADP molecules.
False
The reduced electron carriers NADH and FADH generated in the TCA cycle directly generate most of the ATP produced in cellular respiration.
False
The citric acid cycle is a peripheral process in cellular respiration and does not play a central role.
False
The citric acid cycle is an open loop process.
False
The molecule oxaloacetate combines with acetyl CoA to form a six-carbon molecule called citrate.
True
The citric acid cycle releases three NADH molecules and one FADH2 molecule per turn for each molecule of glucose that enters cellular respiration.
False
The enzyme catalyzing the third step of the citric acid cycle is important in regulating the speed of the cycle.
True
The citric acid cycle goes around twice for each pyruvate made per glucose.
True
Oxaloacetate is regenerated at the end of one turn of the citric acid cycle.
True
The citric acid cycle takes place in the cytoplasm of eukaryotic cells.
False
The citric acid cycle produces two carbon dioxide molecules in the first step and one carbon dioxide molecule in the second step.
False
Isocitrate dehydrogenase catalyzes the conversion of citrate to its isomer, isocitrate.
False
Acetyl CoA joins with a five-carbon molecule to form a six-carbon molecule called citrate in the first step of the citric acid cycle.
False
Test your knowledge on the significance of the citric acid cycle, which is also known as the TCA cycle or Krebs cycle. Explore the various names and key molecules involved in this crucial metabolic pathway.
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