enzymes Flashcards
contact residues
bind to substrate and determine enzyme specificity
catalytic residues
acts on bonds in substrate broken by enzyme action
catabolic
breaking down
anabolic
synthesis
why do enzymes need to be broken down?
to prevent simultaneous backward and forwards reactions from happening
why only a small number of enzymes needed?
- can be re-used
- catalyse reactions at a rapid rate
how do enzymes lower activation energy?
- substrate strained by enzyme to help reach transition state
- enzyme enclose substrate to create favourable environment e.g. acidic environment
- enzymes orientate substrate molecules so reacting bonds are close to each other
what is temperature quotient Q10?
Q10 is the factor by which rate increases for a ten degree rise in temperature
what is the equation for Q10
rate at T + 10C / rate at T
how does cyanide act as a non competitive inhibitor
changes shape of cytochrome oxidase irreversibly and therefore prevents ATP production
state an example of a precursor enzyme
protease synthesised as inactive precursor to prevent damage to proteins in a cell = pepsinogen (inactive) but when HCl added, it is turned back into pepsin.
how can precursor enzymes be activated?
addition of co factor e.g. co-enzymes FAD and NAD
function of filter paper in chromatography
stops plate from drying out
if the sample moved higher up the chromatography paper…
it it less polar = more soluble in a solvent, and so less attracted to plate which is why it moves up.
higher polarity molecules will…
stick/absorb to surface more and therefore move slowly.
