What do ribosomes do?
Ribosomes are attached to Rough Endoplasmic Reticulum (an extensive membrane system found throughout the cytoplasm, and connected to nuclear membrane, acts as transport system) and free in the cytoplasm. It is where the genetic code is made and the site of protein synthesis. They are made of RNA (ribonucleic acid). RNA is smaller than DNA, is single stranded and the pyrimidine (base) thymine never occurs in RNA and is replaced by uracil.