ribosoomist

Ribosomes are essential molecular machines found in all living cells. They are responsible for protein synthesis, a fundamental process for life. Ribosomes are composed of ribosomal RNA (rRNA) and proteins. In eukaryotes, ribosomes are found free in the cytoplasm or attached to the endoplasmic reticulum. Prokaryotic ribosomes are located in the cytoplasm.

The structure of a ribosome consists of two subunits: a large subunit and a small subunit. These subunits come together to form a functional ribosome during protein synthesis. The small subunit is primarily responsible for binding messenger RNA (mRNA), the molecule that carries the genetic code from DNA. The large subunit catalyzes the formation of peptide bonds between amino acids, linking them together to form a polypeptide chain.

The process of protein synthesis, also known as translation, begins when the small ribosomal subunit binds to the mRNA molecule. Transfer RNA (tRNA) molecules, each carrying a specific amino acid, then bind to the mRNA within the ribosome. The ribosome moves along the mRNA, reading the codons (three-nucleotide sequences) and facilitating the sequential addition of amino acids to the growing polypeptide chain. Once the protein is complete, the ribosome disassembles, and the newly synthesized protein is released. Ribosomes are therefore crucial for all cellular functions that rely on proteins.