Inhibition of Enzymes, Cofactors and Activation Energy Flashcards
Why do Enzyme Inhibitors exist?
To help slow or stop enzyme controlled reactions
What is the first type of Enzyme Inhibition?
Competitive Inhibitors
What is a competitive Inhibitor?
A substrate that acts as a competitor with the substrate
What type of bonding do Competitive inhibitors possess with enzyme’s active site?
Weak bonding
Is competitive inhibtion temporary of permanent?
Temporary
How does a competitive inhibitor prevent substrate from binding with Enzyme
Competitive inhibitor binds to active site of enzyme and physically blocks the substrate from binding
How does Competitive inhibition affect rate of reaction
Slows down rate of reaction, but will eventually reach Max Rate
Why does rate of reaction reach the max rate even though competitive inhibitors are present?
With very high [sub], competitive inhibition can be overcome as the chance a substrate will bind to active site iis almost guaranteed.
Competitive inhibition is also reversible as high [sub] can push inhibitor out of active site due to weak bonding
What is the second type of inhibtion called?
Non-competitive Inhibtion
Where does the non-competitive inhibitor bind?
Allosteric Site
What is an allosteric site?
A binding site on enzyme that is not the active site
How does a non-competitive inhibitor prevent substrate from binding with enzyme?
Non-competitive inhibitor binds to allosteric site and changes the enzyme’s active site shape, resulting in denaturing.
Is non-competitive inhibition temporary or permanent
Permanent
Discuss rate of reaction with presense of non-competitive inhibitors
Non-competitive inhibition does not reache the same maximum rate as no inhibition, as inhibitor binds to different site as substrate. Rate of reaction wil be lower.
What is a cofactor?
Non-protein substances that assist enzymes to function
What are the two types of cofactors?
Coenzymes and Inorganic Cofactors
What are coenzymes?
Non-protein organic molecules
Eg: ATP, NADH, vitamins
What are Inorganic Cofactors?
Non-protein, non-organic substances
Eg: Metal ions, minerals
How do cofactors assist enzymes in their function?
Cofactors increase the specifity of the substrate to the active site. Increases strength of binding between enzyme and substrate.
They can also provide atoms/matter or energy to enzyme to assist in catalysis of reaction.
What are the two forms of coenzymes?
- High energy, loaded form
- Low energy, unloaded from
Which 3 imporatnt Coenzymes aid in providing atoms/matter to enzymes?
- NADP+/NADPH (Provide H)
- NAD+/NADH (Provide H)
- FAD+/FADH2 (Provide H2)
Which important coenzyme aids in providing energy to enzymes?
ATP (Energy given through breaking of thirs phosphate bond)
What is activation energy
The minimum amount of energy required for particles to take place in a reaction.
Refferring to heat energy
How do enzymes affect activation energy?
Enzymes lower the activation energy so that more particles have the required energy to react
How do enzymes affect rate of reaction in terms of activation energy
Enzymes lowering activation energy results in increased amount of product formed and speeds up reaction.
What do enzymes do to lower activation energy?
- They bring molecules closer to each other in active site
- Most hydrophobic active sites allow hydrogen bonds and other interactions between substrates to occur
- Amino acids in active site can take/donate H+ which can aid some reactions
