Synthesis of protein occurs on:
**Core Concept**
Protein synthesis is a complex process involving the translation of messenger RNA (mRNA) into a polypeptide chain. This process occurs on ribosomes, which are found in the cytoplasm of eukaryotic cells.
**Why the Correct Answer is Right**
Protein synthesis begins when a ribosome attaches to a messenger RNA (mRNA) molecule, which carries the genetic information from DNA. The ribosome reads the sequence of codons on the mRNA and matches each codon to a specific tRNA molecule carrying the corresponding amino acid. This process is known as translation. Polyribosomes, also known as polysomes, are formed when multiple ribosomes attach to the same mRNA molecule, allowing for the simultaneous synthesis of multiple polypeptide chains. This process is crucial for the rapid synthesis of proteins required for cellular growth and function.
**Why Each Wrong Option is Incorrect**
**Option A:** Mitochondria are responsible for generating energy for the cell through the process of cellular respiration, but they are not directly involved in protein synthesis.
**Option C:** The nucleus is the site of transcription, where DNA is transcribed into mRNA, but it is not the site of protein synthesis.
**Option D:** Golgi bodies are involved in protein modification and secretion, but they are not the primary site of protein synthesis.
**Clinical Pearl / High-Yield Fact**
It's essential to remember that protein synthesis is a highly regulated process, and any disruptions can lead to various diseases, including cancer, neurodegenerative disorders, and genetic disorders. Understanding the basics of protein synthesis is crucial for diagnosing and treating these conditions.
**✓ Correct Answer: B. Poly ribosomes**