where are proteins synthesized inside the cell

Proteins are synthesized inside the cell on ribosomes.

These ribosomes can:

• Float freely in the cytoplasm, making proteins used inside the cell.

• Be attached to the rough endoplasmic reticulum (RER), making proteins that are usually sent to membranes or secreted out of the cell.

A simple way to picture it: ribosomes are like tiny molecular “factories,” and whether they sit alone in the cytoplasm or on the surface of the RER, they are the main site where amino acids are stitched together to form proteins.