Enzymes Revision Carousel Flashcards
(29 cards)
The active site has a ___ shape to the substrate.
Complementary/Specific
Define the term ‘denaturation’.
Loss of Active Site Shape
Explain how an increase of temperature increases enzyme activity.
-Increases particles’ kinetic energy
-Particles move faster and collide more often
-More successful collisions between AS and substrate
Explain how high temperatures can denature enzymes.
-Leads to more vibrations
-Too much vibration breaks the bonds that hold the protein together
What is the temperature coefficient (Q10)?
A measure of how much the reaction rate increases with a 10oC increase
How does a change in pH affect enzymes structure?
-A change in pH refers to change in H+ concentration
-H+ ions interact with polar and charged R groups in tertiary structure
-This breaks the bonds/interactions between R groups, leading to loss of tertiary structure
Explain why can increase in substrate concentration increases rate of reaction.
-Higher successful collision rate
-Between active site and substrate
-Forming more enzyme-substrate complexes
Explain the difference between competitive and non-competitive mechanisms.
C-inhibitory binds to active site so substrate can no longer bind to AS
NC-inhibitor binds to alternative location than the active site (allosteric site) meaning changes 3D structure hence the change in AS
State the difference cofactors and coenzymes.
CF-Non protein component to help enzymes carry out their functions
CE-organic cofactors
Why is it important that some enzymes are produced in its inactive form?
May damage cell it was produced in
What are enzymes?
Biological Catalyst that speed up chemical reactions
What is the difference between the lock-and-key model and the induced fit model?
L&K-rigid, no movement
IF-slight movement of AS to allow better binding to substrate
Name and extracellular enzyme.
Amylase/Trypsin
Most competitive inhibitors are reversible or irreversible?
Reversible
What is end-product inhibition?
The product of an enzyme-catalysed reaction acts as the inhibitor
Name the prosthetic group in carbonic anhydrase.
ZN2+
What are the 3 ways that an enzyme can be activated by changing the tertiary structure?
-Adding a cofactor
-Action of another enzyme
-Change on condition
What are the enzymes’ effect on the activation energy of a reaction?
Enzymes lower Ea
What does it mean by a ‘reversible’ inhibitor?
Inhibitor can be released from the enzyme to resume the enzymes function
Explain how Vmax of the enzyme can be unchanged in competitive inhibition.
-Adding more substrates to out compete inhibitors
-More substrates leads to more successful collisions between enzymes and substrates so more ESC formed
-Therefore less enzymes available for enzymes to bind
What type of inhibitor does aspirin belong to?
Irreversible, Competitive
Explain how an increase in substrate concentration affects the rate of reaction in non-competitive inhibition.
No change as active site is altered by the inhibitor binding in the allosteric site
What is a holoenzyme?
An active form of an enzyme
State the difference between cofactors and prosthetic groups.
CF-temporarily bound to enzyme
PG-permanently bound to enzyme
