4.3.1 Aerobic Respiration: The Acetyl CoA Step Flashcards
1
Q
pyruvate
A
- produced from glycolysis, it enters the mitochondria to begin aerobic respiration
2
Q
aerobic respiration
A
- begins with the conversion of pyruvate to acetyl CoA. This conversion takes place in three steps: decarboxylation, the reduction of NAD+, and the attachment of coenzyme A.
3
Q
note
A
- Some organisms that have no mitochondria or no access to oxygen will undergo fermentation and produce ethanol or lactic acid in the cytosol of the cell.
- Those that do have mitochondria and access to oxygen will undergo aerobic respiration. Aerobic respiration takes place in the mitochondria and requires the presence of oxygen.
4
Q
decarboxylation
A
- (removal of CO2) of pyruvate. A transfer of electrons then takes place, which results in the reduction of NAD+ to NADH + H+. Finally, coenzyme A (a B vitamin derivative) is added to the molecule to produce acetyl CoA. The addition of coenzyme A energizes the molecule and makes it more unstable. When a molecule is unstable, it is more prone to react and release energy; thus, this step has prepared the glucose derivative for more energy release.
5
Q
The acetyl CoA step produces
A
- NADH + H+, and CO2
6
Q
Which of the following statements regarding the acetyl CoA step is false?
A
- During the acetyl CoA step, carbon dioxide is added to pyruvate.
7
Q
The acetyl CoA step in cellular respiration takes place
A
- under aerobic conditions
8
Q
True or false?
The acetyl CoA step is the first step in the Krebs cycle.
A
- false
9
Q
Pyruvate is converted to acetyl CoA in the
A
- mitochondria
10
Q
Comparing glycolysis under anaerobic conditions to glycolysis under aerobic conditions, which statement is true?
A
- Glucose is converted to pyruvate and then lactate under anaerobic conditions, while it is converted to acetyl CoA under aerobic conditions.
