Question

How can only 20 amino acids form the amazing variety of proteins found in living organisms?

Answer 1

With 20 amino acids and proteins made of thousands of amino acids, the possible combinations are immense.

Explanation:

If you think about it, there are only 26 letters in the alphabet, and some are very rarely used. And think of the enormous variety of stories you have read!

Proteins may be tens of thousands of amino acid units long, so the possibilities are virtually endless.

If all proteins were exactly 10,000 units long, the number of possible combinations would be `10,000^20`, or `1xx10^60`. But they aren't all that long, there are some shorter and some longer, which increases the possibilities further.