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.
DNA tells a cell how to make proteins through the genetic code. Both DNA and proteins are long molecules made from strings of shorter building blocks. While DNA is made of nucleotides, proteins are made of amino acids, a group of 20 different chemicals with names like alanine, arginine, and serine.