2 Learning Outcomesapply knowledge of proteins to explain the effects on enzyme activity of:pHtemperaturesubstrate concentrationenzyme concentrationcompetitive inhibitors, and non-competitive inhibitors including heavy metalsdifferentiate between the roles of enzymes and coenzymes in biochemical reactionsidentify the role of vitamins as coenzymes
4 What happens to the rate of most chemical reactions as the temperature is increased? Why?
5 Temperature All enzymes have an optimal temperature Up to this temperature, the reaction rate increases as temperature increasesAbove this temperature, denaturation of the enzyme occurs (irreversible)
6 What would you expect to be the optimal temperature of enzymes that function in the human body?
7 Effect of temperature on enzyme activity Optimal temperatureEnzyme activityTemperature
8 How might a strong acid or base affect a protein?
9 pH All enzymes have an optimal pH High or low pH causes reduced enzyme activity and denaturation of the enzyme
10 Effect of pH on enzyme activity Optimal pHEnzyme activitypH
12 What happens if we increase or decrease the concentration of substrate?
13 Substrate concentration Increasing the substrate concentration increases the reaction rateonly to the point where all enzymes are being used
14 Effect of substrate concentration Enzyme activitySubstrate concentration
15 What if we add more enzyme? How would this happen in the body?
16 Enzyme concentrationIn cells, enzyme concentration is genetically controlled (control of protein synthesis)Increasing the amount of enzyme will increase the reaction rate (as long as substrate is present)
17 Effect of enzyme concentration Enzyme activityEnzyme concentration
18 ActivationEnzymes may be “turned on” by the presence of another molecule (ex. The addition of a phosphate group, known as phosphorylation)
28 Enzyme cofactorsCofactors or coenzymes are non-protein molecules that assist the enzymeMay be inorganic ions ex. Copper, zinc, or ironOften are organic molecules derived from vitaminsFunction is often to transfer electrons or functional groups (ex. Phosphate) to the substrate
29 Vitamin deficiency results in interference with enzyme activity in various metabolic pathways (so eat your veggies!)