Question

Processing, packaging the target proteins for export to cell organelles by shuttling is the job of

• A. Plasma membrane
• B. Nucleus
• C. Endoplasmic reticulum
• D. Transport vesicles

Hint:

Vesicular Transport: Transport Vesicles (COPI, COPII, Clathrin) package and shuttle proteins between ER, Golgi, lysosomes, and the plasma membrane.

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
Vesicular trafficking (COPI, COPII, and clathrin-coated vesicles) mediates anterograde and retrograde cargo protein shuttling between endomembrane organelles.

Step 2: Detailed Explanation:
In the eukaryotic secretory and endomembrane trafficking pathway:
- After initial folding in the endoplasmic reticulum and post-translational modification in the Golgi apparatus, target proteins are sorted, concentrated, and packaged into specialized membrane-bound Transport Vesicles (e.g., COPII-coated, COPI-coated, and Clathrin-coated shuttling vesicles).
- These transport vesicles physically bud, travel along microtubule motor tracks (kinesin/dynein), and dock/fuse via v-SNARE/t-SNARE complexes to deliver cargo to lysosomes, secretory granules, and other destination organelles.

Step 3: Final Answer:
Thus, shuttling cargo is the job of Transport vesicles, matching option (D).