Who proposed the 'Signal hyothesis' meant for the biosynthesis of secretory type of proteins

Options

A. Camillo Golgi
B. Blobel and Sabatini
C. Baltimore
D. Sheeler and Bianchi

Explanation

**Step-by-Step Solution:**

1. **Identify the Hypothesis**: The question asks about the "Signal hypothesis" related to the biosynthesis of secretory proteins.

2. **Determine the Proposers**: The Signal hypothesis was proposed by researchers. In this case, it was given by **Blobel and Sabatini**.

3. **Understand the Concept**: The Signal hypothesis explains how proteins synthesized in the cytoplasm are directed to the endoplasmic reticulum (ER) and Golgi apparatus. This targeting is crucial for the proper functioning and secretion of these proteins.

4. **Explain the Process**:
- Proteins are synthesized in the cytoplasm.
- After synthesis, they are targeted to the ER, specifically the rough endoplasmic reticulum where ribosomes are present.
- The proteins are then transported to the Golgi apparatus.
- The Golgi apparatus packages these proteins into vesicles to protect them from degradation by biological membranes before they reach their final destination.

5. **Summarize the Importance**: The Signal hypothesis is significant as it describes the pathway and mechanisms that ensure proteins reach their correct location in the cell, which is essential for their function.

**Final Answer**: The Signal hypothesis, which explains the biosynthesis of secretory proteins, was proposed by **Blobel and Sabatini**.

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