enzymes Flashcards
what is an enzyme
biological catalyst which speeds up a reaction
how do enzymes differ from chemical catalysts
higher reaction rates
act under milder conditions
greater specificity
can be regualtes
how are enzymes specicif
have aa in active site
properties of aa
different charges
different shapes
different pH
how does an enzyme bind to its substatea
substrate has to have the correct shape and charges in the right place to fit the active site
conformational change around the substrate
what is the transition state
highest energy point where bonds are strained
what do enzymes do to lower activation energy
stables the transition state complex
helps the bonds break in the transition states
(forms extra bonds)
why is there several peaks/troughs of activation energy
most reactions have several different transition states
Two main co factors
coenzymes
metal ions
what do coenzymes do
transfer chemical groups from one reactant to another
aid oxidation reduction reactions
what do metal ions do
coordinate negatively charged groups
i.e. prevents repulsion that would usually occur
accepte/donate e- in oxidation reduction reactions
provide charge and change shape
what is rate of enzyme reactions affected by
temperature
pH
substrate con
how does temperature affect rate
increase in vibrational energy of substrates
how does pH affect rate
causes different ionisation of functional groups leads to different charges in as
what does a low Km mean
high affinity
