Factors Affecting Enzyme Action Flashcards
What must an enzyme have to work
Come into physical contact with its substrate
Have an active site which fits the substrate
What are usually measured in enzyme catalysed reactions
Formation of the products in the reaction
The disappearance of a substrate
How do you measure the rate of change
Draw a tangent on point and then difference in y by difference in x
What’s the effect of temp on enzyme action
A rise in temp increases kinetic energy of molecules. Therefore the molecules move around more rapidly and collide with each other more often. Meaning the enzyme and substrate molecules come together more often in a given time. So there are more effective collisions resulting in more enzyme substrate complexes being formed and so the rate of reaction increases
What’s the graph like when temperature rises
As temp increase substrate fits in more easily
At high temp, enzyme is disrupted so it stops working ( denatured).. once denaturation has occurred its a permanent change and the enzyme does not function again, so the curve drops dramatically
How does pH effect enzyme action
A change inbpah away from the optimum effects rate of reaction
An increase or decrease reduces the rate of enzyme action. If it’s extreme the enzyme becomes denatured
How does pH affect how an enzyme works
Alters change in amino acids that make up active site of enzyme - the substrate can no longer become attached to the active site and so the enzyme substrate complex cannot be formed
It may cause binds maintaining enzyme tertiary structure to break - therefore active site changes shape
What alters the bonding with pH
Change in H+ ions, causing the active site to change shape
How does concentration effect rate of reaction
As long as there’s an excess of substrate, an increase in the amount of enzyme leads to a proportionate increase in the rate of reaction.
What’s the graph like of enzyme concentration on rate of reaction
Initially show increase - there is more substrate then the enzymes active sites can cope with. So if you increase the enzyme concentration, some of the excess substrate can also be acted upon and rate of reaction will increase
The addition of further enzyme molecules has no effect as there are already enough active sites to accommodate all the available substrate molecules. There is no increase in the rate of reaction
Graph will level off as available substrate is already being used as rapidly as it can be by existing enzyme molecules
What are the effects of substrate concentration on enzyme action
As it increases rate of reaction will increase as low substrate concentrations means that enzyme molecules only have limited substrate molecules to collide with - therefore active sites of enzymes aren’t working to full capacity
As more substrate is added, more active sites are filled up until it reaches the point where all of them are working as fast as they can
Graph levels off and an addition of further substrate molecules has no effect as all active sites are already occupied at one time
