Apoint mutation in the mrna for an enzyme results in the replacement of leucine with alanine in the resulting enzyme molecule. why does this change in amino acids have little effect on the biological activity of the enzyme?

The is because both are hydrophobic (due to their neutral side chains) and have approximately the same net charge. The isoelectric point of leucine at 25 degrees centigrade is 6.04 while that of alanine is 6.11.  Therefore, this mutation does not change the structure of the protein hence does not affect its function (if not considerably).

1. amino acid refers to the fundamental building block of proteins, comprising of an amino group and a carboxyl group.

2. catalyst refers to any substance, which increases the rate of chemical reaction without being used up in the reaction.

3. a complex molecule containing he genetic code is dna or deoxyribonucleic acid.

4. an enzyme refers to a molecule of protein, which is unique in accelerating up a particular chemical reaction in the biological systems.

5. nucleic acid refers to an sequence of sugars, phosphates, and nitrogenous bases, for example, dna and rna.

6. a protein refers to a large, composite organic molecule comprising of a huge number of amino acids associated together with the of peptide bonds.

7. rna refers to a nucleic acid that takes part in the production of proteins.

8. substrate refers to a compound, which takes part in a chemical reaction, and is chemically modified by the reaction.