Chapter 5 Test your understanding

7. Which of the following pairs of base sequences could form a short stretch of a normal double helix of DNA?

(A) 5'-AGCT-3' with 5'-TCHA-3' (B) 5'-GCGC-3' with 5'-TATA-3' (C) 5'-ATGC-3' with 5'-GCAT-3' (D) all of these pairs are correct. Answer:C

6. The molecular formula for glucose is C6H12O6. What would be the molecular formula for a polymer made by linking ten glucose molecules together by dehydration reactions?

(A) C60H120O60 (B) C60H102O51 (C) C60H100O50 (D) C60H111O51 Answer:B

1. Which of the following categories includes all others in the list?

(A) disaccharide (B) polysaccharide (C) starch (D) carbohydrate Answer:D

2. The enzyme amylase can break glycosidic linkages between glucose monomers only if the monomers are in the a form. Which of the following could amylase break down?

(A) glycogen,starch, and amylopectin (B) glycogen and cellulose (C) cellulose and chitin (D) starch,chitin, and cellulose Answer:A

4. The structural level of a protein least affected by a disruption in hydrogen bonding is the?

(A) primary level (B) secondary level (C) tertiary level (D) quaternary level Answer:A

5. Enzymes that break down DNA catalyze the hydrolysis of the covalent bonds that join nucleotides together. What would happen to DNA molecules treated with these enzymes?

(A) the two strands of the double helix eould seperate. (B) the phosphodiester linkages of the polyneucleotide backbone would be broken. (C) the pyrimidines would be seperate from the deoxyribose sugars. (D) all bases would be seperated from the deoxyribose sugars. Answer:B

3. Which of the following is true of unsaturated fats?

(A) they are more common in animals than in plants. (B) they have double bonds in their fatty acid chains. (C) they generally solidify at room temperature. (D) they contain more hydrogen than do saturated fats having the same number of carbon atoms. Answer:B