enzymes

An enzyme is a protein biological catalyst that speeds up chemical reactions by lowering the activation energy.

Biochemical pathways involve multiple steps where an enzyme catalyses each step, and the product of the reaction becomes the reactant to the next step.

Enzyme Substrates (1) Specific and complimentary active site in SHAPE & CHARGE Enzyme-substrate complex Product (2) 3 arrows

Inactive (temp ↓ optimum) ↓kinetic energy = ↓ successful collisions = ↓ enzyme-substrate complexes= ↓products + ↓ rate of reaction

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

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

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

The enzymes become saturated (active sites become full)

A factor that prevents the rate of reaction from increasing any further

Enzyme concentration

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 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

Hydrogen peroxide

water and oxygen

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

Enzyme Substrates (2) Specific and complimentary active site Enzyme-substrate complex Product (1) 3 arrows