Read the following statements that describe what happens as an impulse travels. what is the correct order in which the steps occur? 1) the impulse continues to travel down the axon away from the cell body. 2) na+ gates close and k+ ions flow back out of the cell restoring the resting potential. 3) gated k+ and na+ channels are closed. the inside of the cell is slightly negative compared to the outside. 4) the neuron receives a stimulus great enough to start an impulse. 5) gated na+ channels open. the net movement of na+ ions into the cell produces the action potential..

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.