Question

In a fed state when blood glucose concentration is high then:
Statement I: Glucokinase phosphorylate glucose molecule in the hepatic cell but not in the condition when blood glucose concentration is normal as it has a high Km value
Statement II: Activity of hexokinase enzyme is decreased as most of the enzyme is in the form of enzyme-substrate complex
In light of the above statements, choose the most appropriate answer from the options given below:

• A. Both Statement I and Statement II are correct
• B. Both Statement I and Statement II are incorrect
• C. Statement I is correct but Statement II is incorrect
• D. Statement I is incorrect but Statement II is correct

Hint:

Glucokinase: high Km, liver, active in fed state.
Hexokinase: low Km, all cells, inhibited by glucose-6-phosphate.

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Glucokinase and hexokinase are involved in glucose phosphorylation.
They have different kinetic properties.

Step 2: Key Formula or Approach:
No specific formula.
Need to understand the properties of glucokinase and hexokinase.

Step 3: Detailed Explanation:
Statement I: Glucokinase has a high Km value.
It is active only when glucose concentration is high (fed state).
Thus, it phosphorylates glucose in hepatic cells during high blood glucose - correct.
Statement II: Hexokinase activity is decreased due to product inhibition.
When glucose is high, hexokinase is saturated with substrate - correct.
Thus, both statements are correct.

Step 4: Final Answer:
Both Statement I and Statement II are correct.
Hence, the correct option is (A).