Factors affecting enzyme activity Flashcards
What are the two ways which rate of reaction can be measured?
1) How fast the product is made
2) How fast the substrate is broken down
What happens to the enzyme in the reaction if the temperature is too high?
Some of the bonds which hold the active site in its shape break, changing the shape and the enzyme becomes denatured
The substrate will no longer fit into the active site
What pH does pepsin work best at?
2 (acidic)
How does an enzyme become denatured from pH?
The H+ and OH- ions disrupt the ionic and hydrogen bonds which hold the tertiary structure together
Why does a higher substrate concentration increase the rate of reaction?
Higher chance of collisions between substrate and enzyme
More active sites occupied
What is the “saturation” point in terms of substrate concentration?
All of the active sites are full
Increasing the substrate concentration makes no difference to the rate of reaction
What does an increase in enzyme concentration cause an increase of?
Active sites available
Why does the graph for enzyme concentration plateau?
There is a limited amount of substrate and once there is enough enzymes for the amount of substrate, adding more enzymes has no effect on the rate of reaction
What are the two types of enzyme inhibitors?
Competitive and non-competitive
What do competitive inhibitors do?
Block the active site so substrate molecules can’t go in
In terms of competitive inhibitors, why does increasing the amount of substrate increase the rate of reaction?
Theres more chance of the substrate getting to an active site before the competitive inhibitors
What do non-competitive inhibitors do?
They bind to the enzyme away from the active site and change the shape of the active site so that the substrate can no longer fit in it
What impact does increasing the substrate concentration have when non-competitive inhibitors are involved?
None
Where do non-competitive inhibitors bind?
Allosteric site
