Single cell proteins are

Options

A. Proteins synthesised by skin cell
B. A protein synthesised by liver cell
C. Protein synthesised by microorganisms
D. A protein synthesised by muscle cell

Answer

**Step-by-Step Solution:**

1. **Understanding Single Cell Proteins (SCP):**
- Single cell proteins are proteins that are derived from microorganisms. They are often produced in large quantities and can serve as a significant source of protein in human and animal diets.

2. **Identifying the Source of SCP:**
- SCP is synthesized by various types of microorganisms, including bacteria, yeast, and algae. These organisms can convert various substrates into protein-rich biomass.

3. **Analyzing the Options:**
- Option 1: Proteins synthesized by skin cells - This is incorrect as skin cells are not microorganisms.
- Option 2: Proteins synthesized by liver cells - This is also incorrect since liver cells are not microorganisms.
- Option 3: Proteins synthesized by microorganisms - This is correct as SCP is derived from microbial sources.
- Option 4: Proteins synthesized by muscle cells - This is incorrect as muscle cells are not microorganisms.

4. **Conclusion:**
- Based on the definitions and analysis of the options, the correct answer is that single cell proteins are proteins synthesized by microorganisms.

**Final Answer:**
- The correct option is **Option 3: proteins synthesized by microorganisms.**

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