LIFE SCIENCE

Detailed explanation-1: -A polypeptide is a single linear chain of many amino acids (any length), held together by amide bonds. A protein consists of one or more polypeptides (more than about 50 amino acids long). An oligopeptide consists of only a few amino acids (between two and twenty).

Detailed explanation-2: -The linear arrangement of amino acids in a protein is called the sequence, or primary structure, and is highly specific for each protein. Proteins are not usually linear, but fold naturally into organized structures called native structures.

Detailed explanation-3: -Primary structure refers to the linear sequence of the amino acids connected by the peptide bonds.

Detailed explanation-4: -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.