PMDC Verified
Question 47 of 99
In a structural diagram of an immunoglobulin monomer, which chain represents the longer, higher molecular weight polypeptide?
A
Heavy chain
B
Light chain
C
Variable light chain
D
J-chain
Tap any option to test your recall and reveal the step-by-step Propolis autopsy.
Propolis Cognitive Error Autopsy
Official Correct Choice:
Option A: Heavy chain
Concept: Heavy vs. light chain molecular weight.
Solution: An antibody monomer consists of two identical heavy chains (~50 kDa each) forming the core Y-structure and two shorter light chains (~25 kDa each).
Why other options are incorrect:
Solution: An antibody monomer consists of two identical heavy chains (~50 kDa each) forming the core Y-structure and two shorter light chains (~25 kDa each).
Why other options are incorrect:
- Option B & Option C: Light chains are roughly half the length and mass of heavy chains.
- Option D: The J-chain is a small joining peptide found only in dimeric \(\text{IgA}\) or pentameric \(\text{IgM}\) complexes.
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