Fig. 3.24  Phosphorylation mechanism of cAMP-dependent protein kinase (cAPK)

Fig. 3.25  Conformational changes in the catalytic subunit of cAPK.

Fig. 3.26b  Substrate concentration and affinity dependent reaction rates.

Fig. 3.27a  Activation of cAPK by cyclic AMP.

Fig. 3.28  Allosteric regulation of aspartate transcarbamoylase (ATCase).  Orange catalytic subunits are held together by green regulatory subunits.  Binding of the blue CTP molecules cause a conformational change in the regulatory subunits to an inactive state.

Fig. 3.29  Cooperative binding of substrates (red line) in multisubunit proteins shows a greater response within a narrow range of substrate concentrations as compared to single subunit proteins (blue line).  Example, Hemoglobin (red) and myoglobin (blue).

Fig. 3.30  Phosphorylation and dephosphorylation are common mechanisms for regulating protein activity.

Fig. 3.31  Activation of chymotrypsinogen to chymotrypsin by excision of to peptide bonds.