17) Factors Affecting Enzyme Activity Flashcards
- To investigate factors affecting enzyme activity the i_____________ r___________ of r___________ is used to compare conditions.
initial rate of reaction
- An enzyme-substrate complex is formed when a s_________/s collide and bond with an e_________.
substrate/substrates
enzyme
- Factors affecting the rate of enzyme catalysed reactions
1) T
2) _ . _ (acidity)
3) E_________ c_________
4) S_________ c_________
5) I____________
a) c_________ b) n_____________
1) Temperature
2) P.H
3) Enzyme concentration
4) Substrate concentration
5) Inhibitors a) competitive b) non-competitive
- Temperature (Most common in exam)
When the temperature of a solution i____________, the molecules v__________ more
which means:
a. more c_________
b. a higher percentage have the required a___________ e__________
So, more e________ - s__________ complexes are formed.
increases vibrate collisions activation energy enzyme-substrate complexes
- Temperature - Optimum Temperature
Why doesn’t the rate of reaction continue to get faster as the temperature increases?
Because the molecules v__________ more and b__________ i___________ b____________ in the tertiary structure so the bonds being broken are i_____________ and d____________ b____________.
This changes the s_________ of the a___________ s____________ = enzyme d__________
vibrate break internal bonds ionic disulphide bridges shape active site denatured
- P.H (acidity)
The optimum P.H of an enzyme can v_____ depending on its f____________
Different enzymes work in different environments within organisms. Some can work in more acidic environments like the s_________, whilst others work in more alkaline environments like the m_________.
Acids are made up of - H+ (Hydrogen ions)
Alkalis are made up of - OH- (hydroxide ions)
vary
function
stomach
mouth
- P.H (Acidity)
Enzymes have an o__________ P.H. If you i________ or d____________ the P.H away from the optimum, the enzyme activity r_____ will d_________.
This is because the _ _- (alkali) or _+ (acid) will interact with the h___________ b___________ and/or the i_________ b________ which changes the shape of the t______________ structure, which changes the shape of the a_________ s__________ (denatured) resulting in fewer or no e__________ - s___________ complexes being formed.
optimum increase decrease rate decrease OH- H+ hydrogen bonds ionic bonds tertiary structure active site enzyme-substrate complexes
- Enzyme and Substrate Concentration - Enzyme Concentration
As you increase the enzyme concentration the rate of reaction i____________. This is known as a p_________ c___________.
The rate of reaction increases because there are more c____________ between e_________ and s____________ and so more e________-s_________ complexes formed.
increases positive correlation collisions enzymes and substrates enzyme-substrate complexes
- Enzyme Concentration
If the substrate is used up then adding more e___________ will not affect the r________ of r____________.
enzymes
rate of reaction
- Substrate Concentration
As you increase the substrate concentration the rate of reaction i_____________ (p__________ c_________) because there are more c___________ between e_________ and s__________.
Therefore, more e___________-s____________ complexes are formed until all the active sites become o____________.
Now, the l__________ f____________ is the enzyme concentration and adding more substrate will make no difference to the r_______ of r______________.
increases positive correlation collisions Occupied limiting factor rate of reaction
- Inhibitors
An inhibitor is any molecule that reduces or stops a r__________.
reaction
- Inhibitors
Adding a small concentration of an inhibitor will reduce the r__________ of r____________.
rate of reaction
- Inhibitors
If an excess of i____________ is added to a s__________ then the reaction may be prevented c__________!
inhibitors
solution
completely
- Competitive Inhibitors
A competitive inhibitor competes with the s___________.
It fits into the a__________ s__________ of the enzyme instead of the s_______________.
If a competitive inhibitor does fir into the active site, it forms a physical b____________, that prevents the formation of e_________-s__________ complexes.
substrate active site substrate barrier enzyme-substrate complexes
- Competitive Inhibitors
Competitive inhibitors have a l__________ p________ i____________ effect than non-competitive inhibitors.
Catalyzations will take place, but at a s___________ rate as the s_________ is having to compete with the i___________.
N.B. The proportion of substrate to competitive inhibitor will affect how much the r__________ of r_________ changes.
less powerful inhibition slower substrate inhibitors rate of reaction
- Non-Competitive Inhibitors
Non-competitive inhibitors don’t compete with the s_______________.
substrate
- Non-competitive Inhibitors
Non-Competitive inhibitors don’t bind to the active site but to a separate part of the enzyme called its a__________ s_________.
Most non-competitive inhibitors bind p__________________.
allosteric site
permanently
- Non-Competitive Inhibitors
Non-Competitive Inhibitors change the shape of the ______________, so no more enzyme-substrate c__________ are formed.
Therefore, adding more s___________ will make no difference.
active site
complexes
substrates
- Non-Competitive Inhibitors
Have a p____________ effect!
powerful
Roundup
Name the 5 factors that can affect of enzyme catalysed reactions.
1) Temperature
2) P.H
3) Enzyme Concentration
4) Substrate Concentration
5) Inhibitors
Roundup
What measurement is used to compare factors affecting enzyme rate of activity?
The Initial rate of reaction
Roundup
What is formed when a substrate/s collide and bind to an enzyme?
enzyme-substrate complex
Roundup
What happens to the molecules when the temperature of a solution increases?
What affect does this have?
They vibrate more
more collisions, more molecules have the required activation energy so more enzyme-substrate complexes formed
Roundup
If the temperature of a solution increases beyond the optimum temperature, which structure is affected?
Which bonds are broken?
What is the result?
the tertiary structure
ionic and disulphide bridges
the enzyme is denatured
