Answers to Chapter Six

ANSWERS TO CHAPTER SIX

1. Answer: a. The primary structure of a protein is determined by the order of amino acids, which specifically depends on the genetic code that encodes for the protein. 2. Answer: d. While the term “protein” defines any of these, it is the amino acid that is considered the smallest subunit of these structures. 3. Answer: a. DNA will only code for peptides or proteins. It can code for proteins that make the other two substances but does not encode directly for other substances. 4. Answer: b. It is estimated that there are about 20,000 genes in the human genome, although this number is continually being downsized as more information comes out about coding versus noncoding genetic material. 5. Answer: b. The exon is the part of the messenger RNA molecule that remains after splicing in order to make the protein molecule through the translation process. The intron is the part that gets spliced out of the precursor molecule. 6. Answer: c. Each of these is something that happens in the cell to DNA, RNA, and proteins; however, the actual process that starts with messenger RNA and makes protein or polypeptides is called translation. 7. Answer: d. Only the activation energy of the reaction is changed. The total change in energy between substrate and end-product will remain the same and the reaction must be favorable to begin with. 8. Answer: b. The transition state is the unstable state that marks the transition between the substrate and end-product. This energy level is reduced in enzymatic reaction so the reaction happens more quickly and efficiently. 9. Answer: b. This is an immunoassay that is similar to the ELISA test but is harder to do and requires separation of the antibodies with gel electrophoresis in order to do the test. 10. Answer: d. Proteins in gel electrophoresis are separated in the system based on their size and electrical charge.