Enzymes

Question 1

What do enzymes do?

Answer 1

increase rate of reaction by lowering the activation energy of the reaction they catalyse

Question 2

What is the structure of enzymes?

Answer 2

3D tertiary structure globular proteins whose shape is determined by the primary sequence of amino acids

Question 3

What is the active site?

Answer 3

area made up of only a few amino acids and forms a small depression in the overall enzyme

Question 4

What is the induced fit model?

Answer 4

-enzymes are specific to substrates meaning that only one type of substrate fits to the active site on the enzyme
-enzyme substrate complexes form and the structure of the enzyme is altered so that the active site of the enzyme fits around the substrate

Question 5

How does temperature affect the rate of enzymes?

Answer 5

-increases up to optimum temperature as KE of the enzyme increases
+
-above optimum rate of reaction decreases and then stops as the enzyme becomes denatured

Question 6

How does pH affect the rate of enzyme?

Answer 6

if the solution is too alkaline or acidic, then sume shape is altered as the bonds are disrupted in the tertiary structure of the enzyme

Question 7

how does enzyme concentration affect rate of enzyme?

Answer 7

-rate of reaction increases as enzyme concentration increases as there are more active sites for substrate to bind to
-increasing beyond a certain point has no effect on ROR as there are more active sites than substrates so concentration becomes the limiting factor

Question 8

how does substrate concentration affect rate of enzyme?

Answer 8

-as substrate of concentration increases, rate of reaction increases as more enzyme-substrate complexes are formed
-beyond a certain point the ROR no longer increases as enzyme concentration becomes the limiting factor

Question 9

how does the concentration of competitive inhibitors affect the enzyme rate?

Answer 9

• as competitive inhibitors increases, the rate of reaction decreases as the active sites are temporarily blocked by inhibitors so substrates cannot bind to them

Question 10

how does the concentration on non-competitive inhibitors affect enzyme rate?

Answer 10

as concentration of non-competitive inhibitors increases, rate of reaction decreases as the shape of the enzyme is altered