chapter 3 enzymes

define activation energy

the minimum amount of energy required to start a chemical reaction,

before a reaction takes place, activation energy(an energy barrier) must be overcome

define a catalyst

a substance that increases rate of a chemical reaction but remains unchanged at the end of the reaction

describe the uphill, peak and downhill portion of the energy profile

uphill: initial investment of energy required to start a reaction, the activation energy ea

peak: reactants are in unstable transition state where bonds are being broken or formed

downhill: after bonds formed/broken, new molecules settle into their new bonding arrangement to form the product

define an enzyme

a biological catalyst that speeds up biochemical reactions by lowering the activation energy of a reaction

effect of enzyme on a reaction

lowered ea

more reactant molecules can overcome ea to rch transition state to be converted to product molecules

properties of enzymes [6]

enzymes are very efficient(enzyme catalysed reaction is 10^8 faster)

enzymes are needed in minute amts (remain chem unchanged and can be reused)

enzymes hv high degree of specificality (enzymes specific to substrate)

enzymes can be denatured by temperature and pH

enzymes hv optimum pH and temp which they work best in

enzymes can be regulated w activators or inhibitors

what kind of protein are enzymes

globular

how is enzyme denatured

when bonds holding the enzymes in their specific 3d conformation are disrupted

what are the 4 category of amino acids enzymes are made of

catalytic aa: r grp is directly involved in the ctaalytic activity(break/form bond)

binding aa: r grp helps bind w susbtrate to hold in position(non covalent/weak bonds)

structural aa: maintains specific 3d conformation of active site and whole enzyme

non essential aa: no specific function. doesnt matter if they gone

what are cofactors

additional non protein components, enzyme interact w via covalent/weak bonds

what are the three types of cofactors

inorganic metal ions, prosthetic group and coenzymes

describe all three