Sedimentation unit of ribosome is

Options

A. `mu` (micron)
B. `mum` (milimicron)
C. `Ã…` (Angstrom)
D. S (Svedberg)

Answer

**Step-by-Step Solution:**

1. **Understanding Ribosomes:**
- Ribosomes are known as the "protein factories" of the cell because they are the main site for protein synthesis. They are composed of two subunits: a larger subunit and a smaller subunit.

2. **Function of Ribosomal Subunits:**
- The larger subunit is responsible for joining amino acids together to form long polypeptide chains, while the smaller subunit reads the messenger RNA (mRNA) during protein synthesis.

3. **Sedimentation Coefficient:**
- The differentiation of ribosomes is based on their sedimentation coefficient, which is a measure of how fast they sediment when subjected to centrifugal force. This coefficient is expressed in Svedberg units (S), which is a measure of sedimentation rate.

4. **Ribosome Sedimentation Units in Bacteria:**
- In bacteria, the ribosome is classified as 70S, which consists of a 50S larger subunit and a 30S smaller subunit. The "S" stands for Svedberg units.

5. **Identifying the Correct Answer:**
- Among the options provided (micron, millimicron, angstrom, septum), the correct answer is "septum," which refers to the Svedberg unit used to measure the sedimentation rate of ribosomes.

**Final Answer:**
The sedimentation unit of ribosome is the "Svedberg unit" (commonly referred to as "S"), and specifically for bacterial ribosomes, it is 70S.

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