Question 14 of 16
The answer you chose is highlighted in reverse video. The correct answer is in bold.
Major controls of de novo AMP synthesis include:
- 1. allosteric inhibition by GMP.
- 2. allosteric inhibition by AMP.
- 3. availability of PRPP.
- 4. stimulation by GTP..
- A. 1, 2 and 3
- B. 1 and 3
- C. 2 and 4
- D. 4 only
- E. All four
The correct answer is (E).
Comments:
- 1 and 2. Both of these are inhibitors of gln-PRPP amidotransferase and their effect is synergistic.
- 3. Since the kinetics of gln-PRPP amidotransferase are sygmoidal with respect to PRPP, and the concentrations are in the steep part of the curve, [PRPP] can significantly influence the rate.
- 4. GTP provides the energy for the branch from IMP to AMP.
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Last modified 1/5/95