Which cellular structure is responsible for the synthesis of proteins from amino acids?

The ribosomes are the cellular structures that play a crucial role in the synthesis of proteins from amino acids. They act as the site where mRNA (messenger RNA) is translated into a polypeptide chain, which then folds into a functional protein. Ribosomes can be found floating freely in the cytoplasm or attached to the endoplasmic reticulum, where they are involved in translating proteins destined for specific locations, including secretion outside the cell or integration into cellular membranes.

The process of protein synthesis involves the assembly of amino acids in a specific sequence determined by the mRNA, which is transcribed from DNA in the nucleus. Once the ribosome receives the mRNA, it reads the codons (three-nucleotide sequences) and facilitates the binding of complementary tRNA (transfer RNA) molecules, which bring the appropriate amino acids into position to form the growing peptide chain.

Other choices refer to different functions within the cell. The Golgi apparatus is primarily involved in modifying, sorting, and packaging proteins for secretion or delivery to other organelles. The endoplasmic reticulum, while involved in the synthesis of certain proteins and lipids and having a role in their folding and initial modification, is not where the actual assembly of amino acids into proteins occurs