LIFE SCIENCE

Detailed explanation-1: -A protein molecule is made from a long chain of these amino acids, each linked to its neighbor through a covalent peptide bond (Figure 3-1). Proteins are therefore also known as polypeptides. Each type of protein has a unique sequence of amino acids, exactly the same from one molecule to the next.

Detailed explanation-2: -All amino acids contain an amino or NH2 group and a carboxyl (acid) or COOH group. To form polypeptides and proteins, amino acids are joined together by peptide bonds, in which the amino or NH2 of one amino acid bonds to the carboxyl (acid) or COOH group of another amino acid.

Detailed explanation-3: -While there are many types of monomers found in living organisms like simple sugars or nucleotides, the only monomer that forms polypeptide chains are amino acids. When amino acids are joined together, they form peptide bonds.

Detailed explanation-4: -Only −amino acids form polypeptide chains in proteins.

Detailed explanation-5: -For example, proteins are composed of monomers called amino acids. They are linked together to form a polypeptide chain, which folds into a three dimensional (3D) structure to constitute a functional protein (Figure 1).