Question

which molecule enters the citric acid cycle?
a.) lactic acid
b.) glucose
c.) pyruvate
d.) acetyl - coa

Explanation:

• Lactic acid is a product of anaerobic glycolysis and does not directly enter the citric acid cycle.
• Glucose is broken down in glycolysis first and does not directly enter the citric acid cycle.
• Pyruvate is converted to Acetyl - CoA before entering the citric acid cycle.
• Acetyl - CoA (acetyl coenzyme A) is the molecule that directly enters the citric acid cycle. It combines with oxaloacetate to start the cycle.

Answer:

d. Acetyl - CoA