Join thousands of students who trust us to help them ace their exams!
Multiple Choice
During which stage of cellular respiration is the majority of carbon dioxide (\(\mathrm{CO_2}\)) produced?
A
Electron transport chain
B
Glycolysis
C
Krebs cycle (citric acid cycle)
D
Fermentation
0 Comments
Verified step by step guidance
1
Understand the process of cellular respiration, which consists of three main stages: glycolysis, the Krebs cycle (citric acid cycle), and the electron transport chain. Fermentation is an alternative pathway under anaerobic conditions.
Recall that carbon dioxide (\(\mathrm{CO_2}\)) is produced during the breakdown of glucose and other molecules. This occurs when carbon atoms are removed from molecules as part of metabolic reactions.
Review glycolysis: This stage occurs in the cytoplasm and breaks glucose into two pyruvate molecules. No \(\mathrm{CO_2}\) is produced during glycolysis.
Examine the Krebs cycle (citric acid cycle): This stage occurs in the mitochondrial matrix. Pyruvate is converted into acetyl-CoA, which enters the cycle. During the cycle, multiple decarboxylation reactions occur, releasing \(\mathrm{CO_2}\) as a byproduct. This is the stage where the majority of \(\mathrm{CO_2}\) is produced.
Consider the electron transport chain: This stage occurs in the inner mitochondrial membrane and involves the transfer of electrons to produce ATP. No \(\mathrm{CO_2}\) is produced during this stage.