Question

Given below are two statements:
Statement I: Fatty acid synthase is an example of a tetramer of a multienzyme polypeptide.
Statement II: Each polypeptide harbors seven independent enzymatic functions.

• A. Both Statement I and Statement II are true
• B. Both Statement I and Statement II are false
• C. Statement I is true but Statement II is false
• D. Statement I is false but Statement II is true

Hint:

Fatty Acid Synthase = Dimer (2), not Tetramer (4).

Answer 1

The Correct Option is D

Step 1: Concept
Fatty acid synthesis in vertebrates is carried out by a massive multienzyme complex called Fatty Acid Synthase (FAS).

Step 2: Meaning
A "multienzyme polypeptide" means a single long protein chain contains multiple distinct catalytic domains.

Step 3: Analysis
Statement I is false because mammalian FAS is a homodimer (two identical subunits), not a tetramer. Statement II is true: each monomeric subunit in the dimer contains the seven different active sites (plus an acyl carrier protein) required to synthesize palmitate.

Step 4: Conclusion
FAS is a dimer, and each chain is multifunctional. Final Answer: (D)