Enzymes Flashcards
Enzyme
An enzyme is a protein biological catalyst that speeds up chemical reactions by lowering the activation energy.
Biochemical pathway
Biochemical pathways involve multiple steps where an enzyme catalyses each step, and the product of the reaction becomes the reactant to the next step.
3 part enzyme diagram (synthesis)
Enzyme
Substrates (2)
Specific and complimentary active site
Enzyme-substrate complex
Product (1)
3 arrows
Temperature below optimum plan
Inactive (temp ↓ optimum)
↓kinetic energy =
↓ successful collisions =
↓ enzyme-substrate complexes=
↓products + ↓ rate of reaction
Temperature above optimum plan
Denatured (temp ↑ optimum)
Active site changes shape so it is no longer specific and complimentary to substrate
↓ successful collisions =
↓ enzyme-substrate complexes=
↓products + ↓ rate of reaction
pH below optimum plan
Denatured (pH below optimum)
Active site changes shape so it is no longer specific and complimentary to substrate
↓ successful collisions =
↓ enzyme-substrate complexes=
↓products + ↓ rate of reaction
pH above optimum plan
Denatured (pH below optimum)
Active site changes shape so it is no longer specific and complimentary to substrate
↓ successful collisions =
↓ enzyme-substrate complexes=
↓products + ↓ rate of reaction
Enzyme temperature graph
Enzyme pH graph
Enzyme concentration graph
Enzyme substrate concentration graph
Why does an enzyme substrate concentration graph plateau?
The enzymes become saturated (active sites become full)
What is a limiting factor?
A factor that prevents the rate of reaction from increasing any further
What could be the limiting factor in an enzyme substrate concentration graph?
Enzyme concentration
Competitive inhibitor plan
Competitive inhibitor is specific and complimentary to active site of enzyme
It attaches to active site
Substrate can’t attach
Less enzyme-substrate complexes
Less products + lower rate of reaction
Non-competitive inhibitor plan
Non-competitive inhibitors bind to the allosteric site
Active site changes shape so it is no longer specific and complimentary to substrate
↓ successful collisions =
↓ enzyme-substrate complexes=
↓products + ↓ rate of reaction
Enzyme diagram- competitive inhibitor
Enzyme diagram- non-competitive inhibitor
Catalase substrate
Hydrogen peroxide
Catalase products
water and oxygen
How to test if an inhibitor is competitive or non-competitive
Increase substrate concentration.
If rate of reaction increases, the inhibitor is competitive
If rate of reaction stays the same / does not increase, the inhibitor is non-competitive
