Identify the organelles involved in the protein synthesis.
(i) ER
(ii) Ribosomes
(iii) Golgi apparatus
(iv) Nucleus

Options

A. (i), (ii)
B. (i), (ii), (iv)
C. (i), (ii), (iii)
D. (i), (ii), (iii), (iv)

Answer

To identify the organelles involved in protein synthesis, we can break down the roles of each organelle mentioned in the question:

1. **Nucleus**:
- The nucleus is the control center of the cell and contains the genetic material (DNA).
- The process of protein synthesis begins here, as DNA is transcribed into messenger RNA (mRNA).
- Although the nucleus does not directly synthesize proteins, it provides the necessary instructions for protein synthesis.

2. **Ribosomes**:
- Ribosomes are the primary site of protein synthesis in the cell.
- They read the mRNA sequence and translate it into a polypeptide chain, which eventually folds into a functional protein.
- Because of this direct involvement, ribosomes are often referred to as the "protein factories" of the cell.

3. **Endoplasmic Reticulum (ER)**:
- The ER comes in two forms: rough ER (RER) and smooth ER (SER).
- The rough ER is studded with ribosomes, which is why it is associated with protein synthesis.
- It helps in the folding and modification of newly synthesized proteins before they are sent to the Golgi apparatus.

4. **Golgi Apparatus**:
- The Golgi apparatus is involved in the modification, sorting, and packaging of proteins that have been synthesized in the rough ER.
- It plays a crucial role in ensuring that proteins are properly processed and directed to their final destinations within or outside the cell.

**Conclusion**: All four organelles mentioned (Nucleus, Ribosomes, Endoplasmic Reticulum, and Golgi Apparatus) are involved in the process of protein synthesis, either directly or indirectly.