"80-S" ribosome is formed by the combination of:

Explanation

Ribosomes are non-membrane-bounded organelles that are present in large numbers in all living cells and serve as the site of protein synthesis. Ribosomes occur both as free particles in prokaryotic and eukaryotic cells and as particles attached to the membranes of the endoplasmic reticulum in eukaryotic cells. Each ribosome is composed of two subunits, a larger one and a smaller one, each of which has a characteristic shape. Ribosomes are the sites at which information carried in the genetic code is converted into protein molecules. 80S ribosomes are found in eukaryotic cells. 80S ribosomes contain a small 40S subunit and a large 60S subunit. The large subunit (the 60S) catalyzes the formation of the peptide bond, and the small 40S ribosomal unit holds the mRNA molecule so that tRNA can compare and attach amino acids to it.