Topic 1.4.2 - Enzymes Flashcards
1) What is an Enzyme?
Enzymes are proteins with a specific tertiary structure.
2) What is the active site of an enzyme and what is it’s function?
It is the functional part of the enzyme that binds to the substrate by becoming complementary to the
shape of the substrate. This allows the formation of an Enzyme-Substrate Complex (E-S complex).
3) How do enzymes affect the activation energy?
Enzymes lower the activation energy, due to bending bonds, allowing chemical reactions to take place at
lower temperatures than they would otherwise occur (e.g. body temperature).
4) Describe the INDUCED FIT model
●
Enzymes have an active site with a specific shape.
● Before the reaction the active site is not complementary to the substrate.
● Induced fit causes the active site to change shape and becomes complementary as substrate binds
● An enzyme- substrate complex is formed
● This stresses and bends the bonds in the substrate which allows the reaction to occur
5) How might a change in the primary structure result in a non-functional enzyme?
●
A change in amino acid sequence results in different R groups
● Results in a change in hydrogen / ionic / disulfide bonds
● Which results in a change in the tertiary structure
● Which changes the shape of the active site;
● Substrate is not complementary to the active site so no enzyme-substrate complexes form