QUIZ 2, BICH 410 (MWF 1:50 PM), Friday, Oct. 7, 1994
Clearly circle the letter corresponding to your answer for each problem. There are six problems. Five count 3 points each, and one is worth 5 points. No partial credit given for multiple-choice questions.
1. Which of the following amino acids is not a point of attachment for oligosaccharides in glycoproteins?
- A. serine
- B. asparagine
- C. threonine
- D. lysine
2. Which of the following characteristics is not true about nucleic acid bases?
- A. They absorb ultraviolet light strongly around a wavelength of 260 nm.
- B. Adenine can exist in either a keto or enol tautomeric form.
- C. They are roughly planar molecules.
- D. They are nitrogen-containing cyclic molecules.
- E. Cytosine can exist in either a keto or enol tautomeric form.
3. Which of the following is an anomeric pair?
- A. D-glucose and L-fructose
- B. D-fructose and D-glucose
- C. alpha-D-glucose and sucrose
- D. alpha-D-glucose and ß-D-glucose
- E. ß-D-glucose and ß-D-galactose
4. When the linear form of fructose cyclizes, the product is a(n):
- A. oligosaccharide
- B. acetal
- C. hemiketal
- D. ester
- E. glycoside
5. (5 point question) Determine the sequence of an octapeptide given the following properties.
1. The amino acid composition is alanine (ala), arginine (arg), glycine (gly), histidine (his), lysine (lys), methionine (met), phenylalanine (phe), proline (pro).
2. When the octapeptide is treated with fluorodinitrobenzene (FDNB) and hydrolyzed, 2,4-dinitrophenylhistidine is detected by HPLC.
3. When the octapeptide is treated with chymotrypsin, a heptapeptide and free alanine are detected.
4. Digestion of the octapeptide with trypsin gives a pentapeptide, a dipeptide and free lysine. Treatment of the pentapeptide with FDNB, followed by hydrolysis gives dinitrophenylhistidine.
5. Treatment of the octapeptide with cyanogen bromide gives a tripeptide and a pentapeptide. The amino acid composition of the tripeptide is his, met, pro.
The sequence of the octapeptide is:
- A. his-pro-met-gly-lys-arg-phe-ala
- B. ala-phe-met-lys-arg-gly-pro-his
- C. lys-arg-his-pro-met-gly-phe-ala
- D. his-pro-met-gly-arg-lys-phe-ala
- E. ala-phe-his-pro-met-gly-lys-arg
6. Which of the following is not a reducing sugar?
- A. glyceraldehyde
- B. sucrose (glucose(alpha1-2)fructose)
- C. glucose
- D. ribose
- E. deoxyribose