Lesson eLearning

Which enzyme in the human liver is directly inhibited by metformin, thereby reducing hepatic gluconeogenesis?

easy MCQ 1 mark Class 12 · Biology · Human Health and Disease
  1. A) Hexokinase
  2. B) Glucokinase
  3. C) Pyruvate carboxylase
  4. D) Glycogen synthase
Answer
C) Pyruvate carboxylase

The correct answer is C) Pyruvate carboxylase — Step 3: Inhibition reduces substrate availability for gluconeogenesis, lowering hepatic glucose output.

Step-by-step solution

  1. Step 1: Metformin activates AMPK, which in turn downregulates gluconeogenic enzymes.
  2. Step 2: One of the key gluconeogenic enzymes inhibited is pyruvate carboxylase, which converts pyruvate to oxaloacetate.
  3. Step 3: Inhibition reduces substrate availability for gluconeogenesis, lowering hepatic glucose output.
Common mistake: Confusing glucose transport inhibition with gluconeogenesis inhibition

Concept tested: Metformin target enzyme

Published · How this solution was prepared and checked

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