enzymes

Question 1

all enzymes;

Answer 1

globular - generally soluble 
act as catalyst 
specific 
contain active site 
activity affected by pH and temp

Question 2

intra and extracellular

Answer 2

extra - released form cells ( work outside)

intra - found in cytoplasm of cells

Question 3

heterotrophs;

Answer 3

engulf + break down i.e humans

Question 4

enzymes affect activiation energey how?

Answer 4

lower it

Question 5

lock and key

Answer 5

substreta –> enzyme
substare- enzyme complex
product - enzyme complex

Question 6

induced fit hypothesis

Answer 6

substrate -> enzyme
enzyme- substrate complex
enzyne- product complex
( changes sape etc)

Question 7

temp affect on enzymes

Answer 7

too high - denature (tertiary structure - damaged)

optimum temperature KE

Question 8

pH what is it and whats it affect on enzymes

Answer 8

measure of hydrogen ions concentration (H+)
pH values vary, can be refored if damaged
denatrued - too far away from optimum
buffer maintains pH by conc. of H+

Question 9

increasing substrate conc

Answer 9

graph

plateus due to limiting factor

Question 10

imcreasing enzyme conc

Answer 10

graoh a and b

platues due to limiting factor

Question 11

inhibitiors

Answer 11

substance or molecule that slows down enzyme controlled reactions rate by affecting the enzyme molecule

Question 12

competitivce inhibitors

Answer 12

have similar shape to substrate
block active site by forming enzyme-inhibitor complexes
levels depened on conc. of substrate and enzyme
graph

Question 13

non competitive inhibitors

Answer 13

dont compete for active site, instead bind to alisteric site. Affectibg tertiary structure - chaingin active site
GRAPH

Question 14

inhibitors permanent?

Answer 14

competivite = not. described as reversible 
non-competitive= many. effictively denatured

Question 15

cofactors

Answer 15

ensure enzyme-controlled reactions occur at appropriate rate

Question 16

prosthetic groups

Answer 16

coenzyme which is a permanent part of an enzyme contributes to final 3D structure eg; carbonic anhydrase –> zinc-based prosthetic group -vital in RBC

Question 17

coenzymes

Answer 17

small, organnic, non-protein that bind either just before or at the same time as substrate does.coenzymes are recycled and reused.
vitamin B3, helps body break down carbs. + fat to release energy. Vitamin B3 is used in the body to make coezymes. Pellagra results if B3 is absent form the diet.

Question 18

Inorganic ion cofactors

Answer 18

ions can increase reaction rate

ions combine with either enzyme or substrate

Question 19

poisons

Answer 19

can inhibit or overactivate enzymes

Question 20

potassium cyanide eg of poisin inhibitor

Answer 20

inhibits cell respiration. is a non competitive inhibitor for a vital respiratory enzyme called cytochrome oxidase, found in mitochondria. inhibition fo this enzyme decreases the use of O2, so ATP cant be made. Organisism can only anaerobicaly respire, leading to a build up of lactic acid in the blood

Question 21

cystic fibrosis medicines,

Answer 21

enzymes are given

Question 22

ethylene glycol (antifreeze)

Answer 22

when broken down in the liver = by enzymes dehydrogenase, oxalic acid forms (poisinous)
medicine –> fomepizole = inhibitor of enzyme dehydrogenase. reduces rate of acid produced

Question 23

investigating enzyme action variables

Answer 23

temp - water bath
enzyme conc - accuarate measures
sub conc. - accurate measures
pH- buffer solution to control H+ at set level

Question 24

final 3D shape=

Answer 24

hydrophobic amino acid R-group in the centre of the ‘ball’
hydrophillic on outside
amino acids chain, spirals, pleats & turns to give structure