1.5 enzymes Flashcards
what is an enzyme?
a biological catalyst that increase the rate of reaction by lowering the activation energy
what types of proteins are enzymes?
globular proteins that have very specific shapes due to their quaternary structures
what is specificity?
the characteristic of an enzyme that they will only catalyse a specific reaction or group of reactions
what factors affect the efficiency of enzymes?
temperature and pH
what is an anabolic reaction?
a reaction that builds up new molecules in a cell
what is a catabolic reaction?
a reaction that breaks down substances in a cell
what is a metabolism?
the sum of the anabolic and catabolic processes in a cell
what are intracellular enzymes?
enzymes that catalyse the reactions within the cell
what are extracellular enzymes?
enzymes that catalyse reactions outside of the cell which they were made
what lowers the activation energy of a reaction?
the formation of an enzyme-substrate complex
what is the induced fit hypothesis?
a modified version of the lock and key hypothesis for enzyme action where the active site is considered to have a more flexible shape
what are the factors that affect the rate of reaction of enzymes?
- enzyme concentration
- temperature
- substrate concentration
- pH
why is it important to measure initial rate of reaction?
at the beginning of the reaction, there is a very low concentration of products; later in the reaction, products may affect the rates.
what are the two types of inhibition?
reversible and irreversible inhibition
what are the two form of reversible inhibition?
competitive and non-competitive
