Biological molecules 1: Enzymes Flashcards
What are enzymes
Biological catalysts made from proteins that speeds up a reaction
Where can enzyme action occur
Intracellularly or extracellularly
How do enzymes speed up reactions
They reduce the activation energy of the reaction it catalyses
What does the lock and key model explain
That the enzyme’s active site and the substrate and they fit together like a lock and key because they are complementary
What does the induced fit model explain
That enzymes are specific and bonds to one particular substrate and the active site of an enzyme undergoes change to improve the fit once the correct substrate binds to it
What is the difference between the lock and key model AND the induced fit model
The lock and key model states that the active sit of an enzyme exactly fits the substrate whereas the induced fit model states they the
enzyme undergoes change to improve the fit once the correct substrate binds to it
What do substrates and enzymes form then they successfully collide
Enzyme-substrate complexes
What is released after an enzyme catalyses a substrate
The products
Why does the activation energy of substrates decrease when enzyme-substrate complexes form (two reasons)
If two substrate molecules - it being attached to the enzyme reduces any repulsion making the bonding between the substrates easier
If the enzyme is catalysing a breakdown reaction the substrate being attached to the active site is getting its bonds strained, which weakens the bonds
If two molecules need to be joined how can enzyme-substrate complexes assist with this reaction
It reduces any repulsion making the bonding between the substrates easier by being attached to the enzyme
When enzyme-substrate complexes form how does the substrate get weakened
The bonds get strained, which weakens them
How is the active site of an enzyme determined
The tertiary structure
How can the primary structure influence the active site of an enzyme
The primary structure of a protein determines where the hydrogen bonds, the ionic bonds and the disulphide bridges would be in the tertiary structure
What would happen if the tertiary structure of an enzyme is altered
It would change the shape of the active site meaning it will no longer be complementary to the substrate
