Enzymes Flashcards
What are enzymes
Proteins that act as biological catalysts
For intra and extracellular reactions
Formation of enzyme- substrate reactions lowers activation energy
Give two examples of enzymes rhat catalyse extracellular reactions
Trypsin = catalyses hydrolysis of peptide bonds within the small intensine
Amylase= catalyses digestion of starch to maltose
Induced fit model
The shape of the active site is not directly complimentary towards the substrate and is flexible
Changes enable enzyme-substrates to form
However this puts a strain on the substrate bonds, which lowers the activation energy
5 factors that affect the rate of enzyme controlled reactions
Ph Temperature Concentration of substrates Concentration of enzymes Concentration of inhibitors
How does substrate concentration affect the rate of an enzyme reaction
The rate increases unrill it levels off as the max amount of enzyme substrate complexes have been formed
How does enzyme concentration affect the rate of enzyme reaction
The rate of reaction increases untill it levels off as the max number of es complexes form
How does temperature affect the rate of enzyme reaction
Rate increases as the kinetic energy increases, peaks at the optimum temperature
Then levels off as enzymes have now been natured and the active site is no longer complementary
As h bonds have been broken
How does ph affect the rate of reaction
Enzymes have a narrow optimum ph range , after a specifc point it denatures, ionic bonds in enzyme start to break
How do competitive inhibitors work
Binds to the active site of the enzyme as it has a complementary shape, temporarily prevents enzyme substrate complexes fo form untill released
Increasing substrate concentration, decreases this chance
How does non competitive inhibitors work
Binds to the alloesteric site of the enzyme causing the active site to then change
What is product inhibition
When an end product of a reaction then acts as an inhibitor preventing further production of products
Irreversible inhibitors
Completely stops es complexes to form, binds ro the enzyme using strong convalent bonds
Reversible inhibitors
Temporarily inhibits enzyme, may be competitive or non competitive, binds to enzyme using weak h bonds
What are cofactors
Coenzymes
inorganic factors
Prosthetic groups
Non proteins that are required for enzyme activity
What are coenzymes
Organic cofactors,dont bind permanently they transport molecules or electrons between enzymes
