Certified in Public Health (CPH) Practice Exam

When a mutation alters the structure of DNA, the body's effect results from a change in the structure of a(n):

1. Protein

2. Steroid hormone

3. Amino acid

4. Vitamin

The correct answer is: Protein

The correct answer is that a mutation altering the structure of DNA primarily impacts the resulting protein structure. Genes, which are segments of DNA, provide the instructions for synthesizing proteins. When a mutation occurs in a gene, it can change the sequence of nucleotides, which subsequently alters the sequence of amino acids in a protein during the process of translation. This change can affect protein folding, functionality, and interaction with other molecules in the body. Proteins are essential macromolecules that perform a vast array of functions within biological organisms, including acting as enzymes, hormones, and structural components. Therefore, any change at the genetic level can significantly impact the protein produced, ultimately affecting various physiological processes and potentially leading to diseases. The other options—steroid hormones, amino acids, and vitamins—do not directly result from a mutation in DNA. While amino acids are the building blocks of proteins and are influenced by the protein structure, they are not a direct outcome of DNA alterations. Steroid hormones are synthesized from cholesterol and do not derive from genetic mutations, and vitamins are organic compounds that are not synthesized directly from DNA but are rather obtained from the diet.