Letter s in structural unit of ribosome denotes

Options

A. concentration unit
B. Svedberg unit
C. Polymerisation unit
D. Stability unit

Answer

To solve the question regarding what the letter "s" in the structural unit of ribosomes denotes, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Context**: The question is asking about the meaning of the letter "s" in relation to ribosomes. Ribosomes are cellular structures responsible for protein synthesis.

2. **Identify the Options**: The options given are:
- A) Concentration unit
- B) Swedberg unit
- C) Polymerization unit
- D) Stability unit

3. **Research the Term**: The letter "s" in this context refers to a unit of measurement used in biochemistry, specifically in relation to sedimentation rates of particles.

4. **Define the Swedberg Unit**: The Swedberg unit (denoted as "S") is a non-mathematical unit that measures the sedimentation rate of particles in a centrifuge. It reflects how quickly particles settle in a liquid medium, which is influenced by their size, shape, and density.

5. **Relate to Ribosomes**: Ribosomes are composed of ribosomal RNA (rRNA) and proteins, and their sedimentation rates are measured in Svedberg units. For example, the ribosome of E. coli is 70S, which is a combination of its large (50S) and small (30S) subunits.

6. **Conclusion**: Based on the definition and context, the letter "s" in the structural unit of ribosomes denotes the Swedberg unit.

### Final Answer:
The letter "s" in the structural unit of ribosome denotes **B) Swedberg unit**.

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