Question

a. How many different octapeptides can be made from the 20 naturally occurring amino acids?

b. How many different proteins containing 100 amino acids can be made from the 20 naturally occurring amino acids?

Short answer

a. The number of octapeptides from 20 naturally occurring amino acids is .

b. The number of different proteins containing 100 amino acids can be made from the 20 naturally occurring amino acids is 1.3*10¹³⁰

Step-by-step solution

Peptides and proteins

Peptides and proteins are polymers of amino acids. The amino acids are connected via amide bonds.Amino acids are carboxylic acids comprising a protonated amino group on carbon.

The number of octapeptides made from 20 naturally occurring amino acids, and the different proteins containing 100 amino acids can be made from the 20 naturally occurring amino acids  

a. Octapeptides are protein fragments comprising eight amino acids connected in a polypeptide chain.

The number of polypeptides in 20 naturally occurring amino acids can be given by the formula x^y where x indicates the number of amino acids and y indicates the number of spots in the peptide for each amino acid.

So the number of octapeptides formed is given as follows:

20⁸=25,600,000,000

The number of octapeptides from 20 naturally occurring amino acids is 25,600,000,000 .

b. The different proteins containing 100 amino acids that can be made from 20 naturally occurring amino acids are as follows:

20¹⁰⁰=(1.3)10¹³⁰

The number of different proteins containing 100 amino acids can be made from the 20 naturally occurring amino acids is (1.3)10¹³⁰ .