Enzymes Flashcards
What are enzymes?
proteins
What do enzymes cataylse?
metabolic reactions
What do enzymes act as?
biological catalysts
What are the two types of enzyme action?
Intracellular
Extracellular
What structure do enzymes have?
tertiary structure
What is activation energy?
The amount of energy that the chemicals need for the reaction to start
What do enzymes do to the activation energy?
In consequence, what does this do to the rate of reaction?
Lower activation energy
increases rate of reaction
What are the two ways which an enzyme-substrate complex forming lowers the activation energy?
1) Being attached to the enzyme holds the two molecules close together which reduces any repulsion between the molecules which means they can bond more easily
2) Fitting into the active site puts a strain on bonds in the substrate, so the substrate molecule breaks up more easily
What is a catalyst?
A substance which speeds up a chemical reaction without being used up or changed
What is the lock and key model?
The active site of the enzyme and the substrate have a complimentary shape
What is the ‘induced fit’ model?
The shape of the active site changes to fit the substrate
Why can enzymes only bond to one substrate?
The substrate has to be both the right shape to fit the active site and make the active site change in the right way
What determines an enzymes active site?
Their tertiary structure
When will the shape of the active site be changed?
If the tertiary structure of a protein is altered
What may cause the tertiary structure to be altered?
changes in pH or temperature
mutation in the gene which makes determines the primary structure of a protein
