Enzyme Action Flashcards
What do enzymes catalyse
Metabolic reactions both at a cellular level. E.g. respiration and for the organism as a whole
E.g. digestion
Can enzymes affect structures in an organism?
Yes
What is an example of a structure in an organism enzymes can affect
Collagen
What is an example of a function enzymes can affect
Respiration
Can enzymes be intracellular or extracellular?
Both
What doe intracellular mean
Inside of the cell
What does extracellular mean
Outside of the cell
What is the active site of an enzyme
Where the substrate molecules bind to
What do enzymes do to the activation energy of a reaction
Lowers it
What is the activation energy
The certain amount of energy that needs to be supplied to the chemicals before the reaction will start
What is activation energy often offered in the form of
Heat
How do enzymes lower the amount of activation energy needed
By making reactions happen at a lower temperature than they could without an enzyme which speeds up the rate of reaction
What is an enzyme substrate complex
When a substrate fits into the enzymes active site ,it is this that lowers the activation energy
How does the enzyme substrate complex lower the activation energy
If two substrate molecules need to be joined,being attached to the enzyme holds them close together,reducing any repulsion between the molecules so they can bond more easily
Another reason is if the enzyme is catalysing a breakdown reaction,fitting into the active site puts a strain on bonds in the substrate,so the substrate molecules breaks up more easily
What is the lock and key model
This is where the substrates fits into the enzyme in the same way that a key fits into a lock
What does the enzyme-substrate complex do to complete the fit and what does this do
Changed shape slightly and this locks the substrate even more tightly to the enzyme
What is a better theory than the lock and key model
The induced fit model
What is the induced fit model
This helps to explain why enzymes are so specific and only bond to one particular substrate.
The substrate doesn’t only have to be the right shape to fit the active site,it has to make the active site change shape
Enzymes are specific and only catalyse one reaction,what doe maltase only break down
Maltose
What does sucrase break down
Sucrose
Why is is that enzymes only catalyse one reaction each
Only one complementary substrate will fit into the active site
What is the active sites shape determined by
The tertiary structure
What is the enzymes tertiary structure determined by
The primary structure
What happens if the substrate doesn’t match the active site
The enzyme substrate complex won’t be formed and the reaction won’t be catalysed
What happens if the tertiary structure of the enzyme I’d altered in any way
The shape of the active site will change this means the won’t fit into the active site and an enzyme substrate complex won’t be formed and the enzyme will no longer be able to carry out it’s function
