How Many Different Polypeptides Can Be Made from 5 Amino Acids?

[nemzy]

how many diff polypeptides, each composed of 5 amino acids, could be synthesized using the 20 common amino acids?


the answer is simply 20^5 right?

if not, then can u please tell me what I am doing wrong thx

 

[gerben]

theoretically yes 20^5, but some of them may be difficult to synthesize

 

[ravenprp]

Yes, your calculation of 20^5 is correct. This is because for each position in the polypeptide, there are 20 possible amino acids that could be chosen. So for 5 positions, the total number of combinations would be 20 x 20 x 20 x 20 x 20, which is equal to 20^5. Therefore, there could be 3,200,000 different polypeptides composed of 5 amino acids using the 20 common amino acids.