Question

In animal cells, protein synthesis occurs in.

• A. Cytoplasm.
• B. Nucleolus as well as cytoplasm.
• C. Cytoplasm as well as mitochondria.
• D. Ribosomes attached to the nuclear envelope.

Answer 1

The correct option is C

Cytoplasm as well as mitochondria.

The correct option is C.

Explanations of the correct option:

Option C:

1. Protein synthesis is the process where an mRNA is read by ribosomes to synthesize a polymer of amino acids known as a protein.
2. The process is known as translation.
3. The process of protein synthesis occurs in different organelles, such as mitochondria, chloroplasts, cytoplasm, and also rough endoplasmic reticulum in animal cells.
4. Protein synthesis is performed by structures known as ribosomes.
5. Ribosomes are present in mitochondria, cytoplasm, endoplasmic reticulum (ER), etc.

Explanations of the incorrect options:

Option A:

1. The process of translation occurs in the cytoplasm in plant cells.
2. This is because the plant cells have cytosolic ribosomes.
3. Cytoplasm is the jelly-like fluid that submerges all the components of a cell inside the cell membrane.

Option B:

1. Nucleolus is the structure composed inside the cell nucleus.
2. Nucleus is responsible for the synthesis of proteins that make up ribosomes.
3. Then these ribosomal proteins are assembled in the cytoplasm.
4. Hence, ribosomal protein synthesis occurs in the nucleolus.

Option D:

1. Transcription (mRNA synthesis) and translation (protein synthesis) go hand in hand (simultaneously) in animal cells.
2. The outer membrane of ER and nuclear envelope is continuous.
3. The ribosomes attached to the nuclear envelope help in the concurrent protein synthesis of proteins of the endoplasmic reticulum.

Final answer: In animal cells, protein synthesis occurs in the cytoplasm as well as mitochondria.