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.
The ribosome uses the information in messenger RNA to link together the transfer RNA-bound amino acids in the correct order to make each different type of protein in the cell: human cells make nearly 100,000 different types of proteins, each with its own unique messenger RNA sequence.