enzymes (topic 5) Flashcards
what is a catalyst?
a substance that increases the rate of a chemical reaction and is not changed by the reaction
what are enzymes?
proteins that are involved in all metabolic reactions, where they function as biological catalysts
why are enzymes important in all living organisms?
Without enzymes, the rate of reactions in living organisms would be too slow to sustain life
describe enzyme action
each enzyme has a specific and unique shape, active site of enzyme complementary and specific to the substrate of reactant, this is the enzyme-substrate complex, reaction happens, product of reaction leaves active site
what is denaturation
permemnant change in enzymes active site, making it not useable anymore, due to high temperature or change ph
enzyme action and ph
changes in ph alter forces of attraction between different parts of an enzyme molecule, there is an optimum ph, in which the enzyme rate of reaction is at its highest, above or below this ph denaturation happens, eg optimum ph of pepsin= 2, amalyse- 7
explain what is needed for a chemical reaction to happen, int terms of collisions and energy
reactant particles must collide, collision must have enough energy, no reaction if particles dont collide or dont have enough kinetic energy, collision that results in a chemcical reaction is an effective collision, greater frequency of effecitive colllsion faster rate of reaction
what is activation energy
The minimum amount of energy needed for a reaction to occur.
increasing temp and enzyme rate of reaction
As the temperature increases, particles gain kinetic energy and move faster. This makes them more likely to collide with each other, and a greater proportion of these collisions will have the required activation energy. As a result of this, the frequency of effective collisions increases, and so the rate of reaction increases. If temperature passes optimum, enzymes can denature
