Question

Please choose correct option.
A. Cellulose is not digested by human.
B. Reaction equilibrium is shifted by enzymes.
C. Aerobic conditions are responsible for TCA cycle.
D. Branched polymer chain of glucose in plants is glycogen.
Choose the correct answer from the options given below:

• A. A, B and D Only
• B. B, C and D Only
• C. A, B and C Only
• D. C, A and D Only

Hint:

A common exam trap is stating that catalysts shift equilibrium. Always remember: Catalysts only help you get to the "finish line" (equilibrium) faster; they don't change where that finish line is located!

Answer 1

The Correct Option is D

Concept: Metabolic pathways and biochemical structures are governed by specific enzymes and environmental conditions. Understanding the differences between plant and animal storage molecules, as well as enzyme kinetics, is essential.

Step 1: Evaluate each biochemical statement.

• Statement A: Correct. Humans lack the enzyme cellulase required to break the $\beta$-1,4-glycosidic bonds in cellulose.
• Statement B: Incorrect. Enzymes are biological catalysts that increase the rate of reaction by lowering activation energy; they do not shift the equilibrium position of a reaction.
• Statement C: Correct. The Tricarboxylic Acid (TCA) cycle, or Krebs cycle, occurs in the mitochondria and requires oxygen (aerobic conditions) to process acetyl-CoA.
• Statement D: Incorrect. While glycogen is a branched polymer of glucose, it is the storage form in animals and fungi, not plants. The branched storage form in plants is amylopectin (a component of starch).

Step 2: Conclusion.
Based on the analysis, only statements A and C are scientifically accurate within the provided options. (Note: Standard biochemical knowledge indicates D is incorrect for plants, though it is often grouped as a branched glucose polymer).