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| Adidoc2k1 Total Posts: 60 | Posted: Mon Jan 14, 2008 01:13 pm q. under physilogical conditions the phosphorylase b in the muscles is unedr the inhibitory effect of: a.ATP b.AMP c.Glucose d. Ca2+ |
| gourab Total Posts: 12 | Posted: Mon Jan 14, 2008 03:32 pm The position of the equilibrium of phosphorylase b between the T[Tense state] and the R[Relaxed state---this is active state] form is responsive to conditions in the cell. Muscle phosphorylase b is active only in the presence of high concentrations of AMP, which binds to a nucleotide-binding site and stabilizes the conformation of phosphorylase b in the R state (Figure 21.11). ATP acts as a negative allosteric effector by competing with AMP and so favors the T state. Thus, the transition of phosphorylase b between the T and the R state is controlled by the energy charge of the muscle cell. Glucose 6-phosphate also favors the T state of phosphorylase b, an example of feedback inhibition. |
| kkrish Total Posts: 274 | Posted: Mon Jan 14, 2008 06:33 pm yup  |