Which part of the cell is primarily involved in protein synthesis?

The ribosome is primarily involved in protein synthesis because it is the site where amino acids are assembled into proteins according to the sequence of messenger RNA (mRNA). Ribosomes can be found floating freely in the cytoplasm or attached to the endoplasmic reticulum, forming a rough appearance, which is why this organelle is essential for translating the genetic information carried by mRNA into functional proteins.

In addition, ribosomes facilitate the interaction between the mRNA and transfer RNA (tRNA), which brings the appropriate amino acids to the ribosome, where the protein chain is elongating. This process is fundamental for cell function, growth, and repair, highlighting the ribosome's crucial role in the central dogma of molecular biology, which connects DNA, RNA, and protein synthesis.

The other choices, such as the Golgi apparatus, plasma membrane, and lysosome, have various functions but are not directly responsible for synthesizing proteins. The Golgi apparatus is involved in modifying, sorting, and packaging proteins for secretion or delivery to other organelles, the plasma membrane serves as a barrier that regulates the passage of substances in and out of the cell, and lysosomes contain enzymes for digestion and waste removal. Each of these organelles plays a