True about ribosomes
**Core Concept**
Ribosomes are the cellular organelles responsible for protein synthesis. They read messenger RNA (mRNA) sequences and assemble amino acids into polypeptide chains. This process involves the translation of genetic information from the DNA to the production of proteins.
**Why the Correct Answer is Right**
Ribosomes are composed of two subunits: the large subunit and the small subunit. They are found in both prokaryotic and eukaryotic cells, although eukaryotic cells have a larger number of ribosomes. The ribosomal subunits are made up of ribosomal RNA (rRNA) and proteins. The ribosomes bind to mRNA and use the sequence information to assemble the amino acids into a polypeptide chain. This process is essential for the synthesis of all proteins in the cell.
**Why Each Wrong Option is Incorrect**
**Option A:** Incorrect because ribosomes are not directly involved in the process of transcription, which is the synthesis of RNA from DNA. Transcription occurs in the nucleus, whereas ribosomes are found in the cytoplasm.
**Option B:** Incorrect because ribosomes do not have the ability to synthesize ATP from ADP and Pi. This process is carried out by the mitochondria through cellular respiration.
**Option C:** Incorrect because ribosomes are not directly involved in the process of DNA replication. DNA replication occurs in the nucleus and involves the unwinding of DNA and the synthesis of new DNA strands.
**Clinical Pearl / High-Yield Fact**
It's essential to remember that ribosomes are the site of protein synthesis, and any mutations or defects in ribosomal function can lead to various diseases, such as ribosomal disorders.
**Correct Answer: None, as the options were not provided. However, if a correct option was provided, it would be filled in accordingly.**