Anyone can get melasma, but it is more common among young women. Melasma often appears during pregnancy, in the second or third trimesters. Doctors don't know exactly what causes melasma, but the condition is associated with the female hormones estrogen and progesterone.
A ribosome is made of numerous proteins and RNA. Function The Golgi complex takes proteins made by the endoplasmic reticulum and exports them out of the cell as needed. It is able to keep dangerous proteins from damaging the cell which made them. It is like a packaging department ready to deliver the protein products made in the cell.
How are proteins made? To make a protein, a cell must put a chain of amino acids together in the right order. RNA is similar to DNA: it consists of strands of four different chemical building blocks, or bases, attached to a chemical backbone. All proteins are made up of combinations of 20 different amino acids.