| Question |
Answer |
| What are enzymes primary function | They speed up reactions without being consumed |
| True or False: Enzymes do not shift the equilibrium, they just reach it faster? | True |
| What macronutrient are enzymes? | Proteins |
| Cofactor | Inorganic component (minerals) needed to make the reaction work |
| Coenzyme | Organic component (vitamins) needed to make the reaction work |
| Holoenzyme | Complete enzyme: functional enzyme |
| Apoenzyme | Enzyme missing cofactor or coenzyme |
| Zymogen | Enzyme precursor: Must be converted to active form |
| Name the classes of enzymes | Oxidoreductase, transferase, hydrolase, lyase, isomerase, ligase |
| Oxydoreductase | Transfer e- from donnor to acceptor for redox reaction. NAD or FAD |
| Transferase | Transfer a functional group. Breaking the bond on one molecule and putting it on another. |
| Hydrolase | Water is a reactant...digestion! |
| Lyase | Adds water, CO2 or ammonia to doubble bond or removes them from double bond |
| Isomerase | Rearranges functional groups |
| Ligase | Joins bond between C and a O, S or N... has a Pi in results and uses ATP |
| Induced fit model | Most common active site model... not lock and key |
| When [s] = km, them Vo = ? | 1\2 Vmax |
| When Vo = 1|2 Vmax then [s] = ? | Km |
| If the concentration of substrate [s] is smaller than Km, what is the reaction dependant on? | Substrate |
| When the concentration of substrate is bigger than Km, what is the reaction dependant on? | Enzymes |
| Name 4 factors effecting enzyme activity | 1. Environmental 2. Enzyme and substrate concentration 3. cofactors and coenzymes 4. Effector |
| Environmental effect on enzymes: temperature | Heating up an enzyme will make the reaction go faster. However, when you heat up an enzyme, it will eventually become denatured. |
| Environmental effect on enzymes: pH | Each enzyme has an optimum pH which depends on pK |
| [e] and [s] effects | Excess of substrate = velocity of rxn depends on [e] |
| Cofactor and coenzymes | Vitamin and mineral deficiencies will decrease enzyme activity |
| Effectors | Activators = increase activity Inhibitors = decrease activity |
| Competitive Inhibitor | Vmax does not change but Km will change because you have "competition" for the binding site of the enzyme |
| Noncompetitive Inhibitor | Km will stay the same but Vmax will change because you have no competition for the binding site but the inhibitor is making the molecule harder to bind with the substrate |
| Ternary Complex | |
| Enzyme Regulation | 1. Covalent Modification 2. Modulation of Allosteric Enzymes 3. Increase [E] by induction |
| Covalent Modification | Primary was to regulate cellular enzymes. Adding or removing a phosphate group. Dependant on enzyme...can turn it on or off. |
| Phosphorylation of glycogen phosphorylase ____ activity | Increases |
| Phosphorylation of glycogen synthase ____ activity | Decreases |
| Allosteric Enzymes | Regulatory enzymes in a cascade (rate limiting). Activator or inmhibitor binds to an allosteric site on the enzyme. Feedback inhibition. Tells the enzyme to speed up or slow down. Act like a noncompetitive inhibitor. |
| Enzyme Induction | Slowest of all regulations . Cells can regulate the amount of E by induction. Inductions occur from hormones and diet. Ex. Insulin |
Ch.18 LTI-MA 509
