Question

The correct order of events of Cori cycle after muscular activity is:
A. Conversion of glycogen to glucose in muscle
B. Reduction of lactate to pyruvate in liver
C. Gluconeogenesis of pyruvate in liver
D. Production of pyruvate in muscle
E. Reduction of pyruvate to lactate in muscle which goes to liver
Choose the correct answer from the options given below:

• A. E, B, C, D, A
• B. A, D, E, B, C
• C. A, D, E, C, B
• D. A, D, C, E, B

Hint:

Muscle: Glycogen → Lactate Liver: Lactate → Glucose

Answer 1

The Correct Option is B

Concept:
The Cori cycle describes the metabolic pathway in which lactate produced by anaerobic glycolysis in muscle is transported to the liver, converted back to glucose, and returned to muscle.

Step 1: Glycogen breakdown in muscle.
During intense muscular activity:
• Glycogen stored in muscle is broken down into glucose Thus: \[ A: Conversion of glycogen to glucose \]

Step 2: Glycolysis in muscle.
Glucose undergoes glycolysis:
• Producing pyruvate Thus: \[ D: Production of pyruvate \]

Step 3: Anaerobic conversion.
In low oxygen conditions:
• Pyruvate is reduced to lactate
• Lactate enters bloodstream and goes to liver Thus: \[ E: Reduction of pyruvate to lactate \]

Step 4: Liver conversion.
In the liver:
• Lactate is converted back to pyruvate Thus: \[ B: Reduction of lactate to pyruvate \]

Step 5: Gluconeogenesis.
Pyruvate is then:
• Converted into glucose via gluconeogenesis Thus: \[ C: Gluconeogenesis \]

Step 6: Final sequence.
\[ A \rightarrow D \rightarrow E \rightarrow B \rightarrow C \] \[ \boxed{\text{Correct answer = Option (2)}} \]