The reason you breathe heavily while exercising is that your body is trying to take in oxygen to fuel aerobicrespiration and generate enough ATP to replenish the ATP you use during exercise. If you are exercising vigorously, the need for ATP might be greater than the amount of oxygen you can inhale. In this situation, your body cells generate ATP through lactate fermentation. As you continue vigorous exercise, your muscles might begin to "burn," causing you to stop and rest. This burning sensation is the result of a chemical buildup in your muscle cellsBased on this information , which of the following chemicals likely causes pain in over-exercised muscles?

b brown mice / white sand dunes

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.