AP BIOLOGY

Detailed explanation-1: -Nearly all the proteins required by cells are synthesised by ribosomes. Ribosomes are found ‘free’ in the cell cytoplasm and also attached to rough endoplasmic reticulum. Ribosomes receive information from the cell nucleus and construction materials from the cytoplasm.

Detailed explanation-2: -The free-ribosomes synthesize soluble cytoplasmic proteins, peripheral membrane proteins, mitochondrial proteins, chloroplast proteins, peroxisomal and nuclear proteins, etc. In short, free-ribosomes are responsible for the production of all the proteins that are found within the cell and are present in the cytosol.

Detailed explanation-3: -The endoplasmic reticulum can either be smooth or rough, and in general its function is to produce proteins for the rest of the cell to function. The rough endoplasmic reticulum has on it ribosomes, which are small, round organelles whose function it is to make those proteins.

Detailed explanation-4: -If the endoplasmic reticulum (ER) has ribosomes attached to it, it is called rough ER; if it does not, then it is called smooth ER. The proteins made by the rough endoplasmic reticulum are for use outside of the cell.

Detailed explanation-5: -Ribophorin, also known as a ribosome receptor protein, is a transmembrane glycoprotein that aids in the binding of ribosomes to the endoplasmic reticulum’s outer surface, generating rough endoplasmic reticulum.