Question 30:
The catabolic lysosomal degradation of cellular proteins is called:
Autophagy is the lysosomal process degrading cellular proteins catabolically. The correct answer for Question 30 is (B) Autophagy.
Correct Answer
Option (B) Autophagy is correct. Autophagy delivers cytoplasmic proteins and organelles to lysosomes via autophagosomes, where lysosomal hydrolases degrade contents into amino acids for recycling—essential for homeostasis and stress response.
Option Explanations
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(A) Phagocytosis: External particle engulfment by plasma membrane forming phagosomes that fuse with lysosomes; targets bacteria/pathogens, not intracellular proteins.
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(B) Autophagy: Correct; macroautophagy engulfs cytosolic proteins in double-membrane autophagosomes fusing with lysosomes for catabolic degradation.
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(C) Chaperon: Misfire; chaperones (e.g., Hsp70) assist folding/prevent aggregation, not degrade via lysosomes (note: likely “chaperone” misspelling).
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(D) Autotroph: Organism synthesizing organics from inorganics (e.g., photosynthesis); unrelated to cellular protein catabolism.
Options Comparison
| Option | Process Type | Lysosomal Protein Catabolism? | Key Role |
|---|---|---|---|
| (A) Phagocytosis | External uptake | No | Immunity |
| (B) Autophagy | Intracellular recycling | Yes | Proteostasis |
| (C) Chaperon | Protein folding | No | Maturation |
| (D) Autotroph | Nutrition mode | No | autotrophy |
