(LE 2) Enzymes and Energy Flashcards
What is enzyme activity? What is it influenced by?
Rate at which substrate is converted into product
- temperature
- pH
- substrate and enzyme concentration
- cofactor and coenzyme concentration
- stimulatory or inhibitory effects of products on enzyme function
How is enzyme activity used clinically?
amount of enzyme in a sample can be based on the rate of product synthesis. Abnormally high plasma concentrations of certain enzymes are indicative of disease
What is the function of a cofactor and coenzyme?
Cofactors: typically metal ions. used to help change shape of enzyme
coenzymes: derived from vitamins; transport small molecules needed by enzymes
Are enzymes always active? If not, how are enzymes activated and deactivated?
No
activated by phosphorylation and inactivated by dephosphorylation
What determines the direction in which the reaction is catalyzed by the enzyme?
Law of mass action: reactiion happens high side to low side
What are the first and second laws of thermodynamics?
- energy cannot be created or destroyed, only changed
- energy is lost with each transformation through heat