Term | Definition |
Endothermic reaction | A reaction that requires energy input |
Exothermic reaction | A reaction that gives off energy |
Enzymes (4 Characteristics) | -Lower activation energy of a reaction.
-Increase the rate of the reaction.
-Do not affect the overall (delta)G or (delta)H of the reaction
-Are not changed or consumed in the course of the reaction |
Apoenzymes | Enzymes without their cofactors |
Holoenzymes | Enzymes that contain their cofactors |
Allosteric Enzymes | An enzymes that has multiple binding sites. The active site is present, as well as at least one other site that can regulate the availability of the active site |
Allosteric activators | An activator will result in a shift that makes the active site more available for binding to the substrate |
Allosteric inhibitors | An inhibitor will result in a shift that makes the active site less available for binding to the substrate. |
Feedback Inhibition | In feedback inhibition, the product may bind to an enzyme or enzymes that acted earlier in its biosynthetic pathway, thereby making the enzyme unavailable for other substrate to use. |
Competitive Inhibition
[How can it be overcome?] | An enzyme inhibitor that binds to the active site, thus competing with substrate.
[It can be overcome by adding more substrate] |
Noncompetitive Inhibition
[How is it overcome?] | An enzyme inhibitor that binds to an allosteric site instead of the active site, which induces a change in enzyme conformation.
[Cannot be overcome by adding more substrate. Can't be overcome at all] |
Irreversible Inhibition | An enzyme inhibitor that binds to the active site and makes it permanently unavailable. |
Zymogen/Proenzymes | An inactive enzyme precursor. |