Enzymes/enzyme action Flashcards
what are enzymes?
biological catalysts that speed up the reaction by lowering the activation energy of a reaction without being used up
why are enzyme shighly specific?
because of their tertiary structure
what does the locke and key model state?
the substrate fits into the enzyme like a key and a lock - the active site is an exact fit
why does the induced fit model go against the landk model?
it states that enzymes arent an exact fit - the active site changes shape as the substrate binds to fit = forming es complexes
what are the three factors that affect enzyme activity?
- Temperature 2.Ph 3. Enzyme conc 4. Sub conc
Temp. increase in temp
increase in temp = increases the rate of reaction - more kinetic energy/more molecules have the activation energy = more successful collisions between the AS and Substrate = ES complexes
Temp above opt temp
vibrations break the hydrogen bonds - alters the tertiary structure, so it changes the shape of the active site = the enzyme is denatured
How does Ph affect enzyme activity
opt ph - the h+ and OH-ions interact with the ionic and hydrogen bonds/affecting the tertiary structure
= enzyme becomes denature
how does enzyme conc/sub conc
increase in enzyme conc increase the rate reaction, successful collisions with substrate molecules (vice versa), forming more es complexes
- reaches the saturation point - when all the substrate molecules are used up, so further increase has no effect.
what are the two types of inhibitors?
- competitive
2. non competitive
What are competitive inhibitors? 2 points
- similar shape to the substrate molecules
- compete with the sub to bind to the AS, block the sub molecule and prevent the normal reaction from taking place
what are non competitive inhibitors?2 pointd
- different shape to sub molecule
- bind to the enzyme away from the AS, changing the shape of the AS, the sub can’t bind to the AS
