Diseases that already exist in a community where it is maintained in a low but constant incidence are said to be epidemic. a. true b. false

the sugar-phosphate backbone forms the structural framework of nucleic acids, including dna and rna. this backbone is composed of alternating sugar and phosphate groups, and defines directionality of the molecule.

the three components of a nucleotide are the nitrogenous base, the phosphate group and the five-carbon sugar.

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.