Bioenergetics and Cellular Respiration
|As we have discussed, a centrally important context for allosteric interactions is in the negative feedback control mechanisms for enzyme activity, but there are other types of situations where allosteric interactions are important. For example, induced fit describes allosteric changes whereby the binding of substrate produces a conformation change in the enzyme. Induced fit can act to exclude water from the active site, as well as undesirable reagents, preventing undesirable side reactions. Examples of substrate binding which enables large conformational changes of protein enzymes include the closure of the cleft of hexokinase upon binding glucose in glycolysis and the conformational changes of citrate synthase on binding oxaloacetate in the citric acid cycle. A similar process occurs with the transport protein hemoglobin, upon binding oxygen, where conformational changes are produced that increase the oxygen affinity of hemoglobin. As hemoglobin binds oxygen, its affinity to bind more increases. This is why we say that oxygen binding is cooperative with hemoglobin.|
Let me say again. I am trying to build your comfort with nomenclature and comprehension skills in reading biochemically oriented discussions. It is acclimitization not memorization.