Question

Why do different proteins contain a different number and a different sequence of amino acids?

Answer 1

One or more polypeptides together forms a protein.

Explanation:

When a particular protein is formed it is a long polypeptide . The polypeptide is with definet number of amino acids. The amino acids have reacting groups exposed. It makes folding of a polypeptide. The protein folding is responsible for its function. Any mistake in protein folding or its sequence of amino acids makes protein unique. The number of proteins present in a cell therefore is more than 100,000.

Answer 2

Proteins different in length and compositions because the sequence that makes them (their gene) is composed of different nucleotides. Different genes have different nucleotide sequences, and hence different proteins are produced.