Match Analysis

A. Caspases → IV. Apoptosis. Correct—caspases (3,7,9) are cysteine proteases that systematically dismantle cells during programmed death.

B. Proteases → I. Degradation. Correct—endopeptidases/exopeptidases hydrolyze peptide bonds, essential for protein turnover (ubiquitin-proteasome, lysosomes).​

C. Polymerases → II. Replication. Correct—DNA/RNA polymerases synthesize nucleic acids using templates during genome duplication/transcription.

D. Kinases → III. Signalling. Correct—transfer phosphate from ATP to proteins/lipids, creating signaling cascades (e.g., MAPK, PKA pathways).

Option Breakdown

• (1) A-IV, B-II, C-I, D-III: Wrong—proteases ≠ replication; polymerases ≠ degradation.

• (2) A-IV, B-III, C-II, D-I: Wrong—proteases ≠ signalling; kinases ≠ degradation.

• (3) A-IV, B-I, C-III, D-II: Wrong—polymerases ≠ signalling; kinases ≠ replication.

• (4) A-IV, B-I, C-II, D-III: Perfect—each enzyme matched to hallmark function.

Caspases drive apoptosis by cleaving structural proteins, while proteases mediate degradation, polymerases enable replication, and kinases control signalling pathways.​

Function Summary Table

Biological Context

• Apoptosis: Caspase cascade (initiator 8/9 → effector 3/7).

• Degradation: Protein quality control, nutrient recycling.

• Replication: S-phase DNA synthesis.

• Signalling: Receptor → nucleus gene activation.​

Exam Mnemonic

“CaPRiK”: Caspases=Apoptosis, Proteases=Recycling(Degradation), Polymerases=Replication, Kinases=Signalling. Option (4) sequence.​