Enzymes Flashcards
what is catalase
tetramer (quaternary structure) of 4 polypeptide chains
4 haem groups
optimum pH- 7
what is trypsin (protease)
hydrolyses proteins
breaking down food proteins
optimum pH 8
what is amylase
catalyses starch into sugars
made in pancreas and salivary gland
optimum pH 7
what are extremophiles
organisms that survive in extreme heat conditions
enzymes more stable due to increased bonds or antifreeze proteins
factors affecting enzyme activity
temperature- denatures
pH- dentaures
enzyme conc.- more active sites
substrate conc- enzyme limiting factor
What group do hydrolases and ATP
Intracellular
Reactions that are required for growth
Anabolic
Enzymes that are released and work from outside the cell that made them
Extracellular
How does temperature affect enzymes
Increases KE- more collisions
Denaturation- bonds between protein vibrate more
Vibrations increase until the bonds strain and then break
This causes a change in tertiary structure
How does pH affect enzymes
Alters the structure of enzyme and active site
Competitive inhibition
Interferes with active site so substrate can’t bind
Reversible
Reduces rate of reaction
Non-competitive inhibition
Inhibitor binds to enzyme (not substrate) changing site of active site as tertiary structure is changed
Irreversible/reversible
What 3 things do enzymes need
Coenzymes
Cofactors
Prosthetic groups
What do coenzymes do
Aid in recognising, attracting and repulsing a substrate (vitamins)
What do cofactors do
Increase rate of reaction or required for enzyme to function
Activated proteins
(Cl- for amylase)
