cofactors and enzyme inhibition Flashcards
what are cofactors
and why are they essential for some enzymes
cofactors are non protein substances that bind to an enzyme to make them work
cofactors work by helping the enzyme and the substrate bind together
cofactors are normally inorganic molecules or ions
what are ORGANIC cofactors called
coenzymes
these participate in the reaction and are changed by it, unlike cofactors
- They carry chemical groups between different enzymes, and are continually recycled during the process
what is a cofactor that is tightly bounded to the enzyme called
prosthetic group
what are the two different types of enzyme inhibitors
competitive
non competitive
Enzyme inhibitors bind to the enzyme
competitive Inhibiton
- similar shape to substrate molecule
- they compete with substrate molecules to bind to the active site, but no reaction takes place
- instead they block the active site, so no substrate molecule can fit in it
to combat this we increase the substrate concentration, which will mean that the substrate has a higher chance of getting to an active site before the competitive inhibitor
Non-competitive inhibition
- bind to a part of the enzyme away from the active site ( Allosteric site)
- causes the active site to CHANGE SHAPE so the substrate molecules can no longer bind to it
- dont compete with substrate molecules as they are different shapes
- increasing substrate concentration, wont make any difference
what is an inhibitor that has strong covalent bonds known as
Irreversible inhibitor
what is an inhibitor that has weaker hydrogen bonds know as
Reversible inhibitor
why can enzyme inhibitors be bad
stops some reactions from occurring by inhibiting enzymes that catalyse respiration
- cells that cant respire die
including:
1) cyanide (irreversible inhibitor) - which inhits cytochrome C oxidase, which catalyses respiration reactions, so cells that cant respire die
2) Malonate (inhibits succinate dehydrogenase)
3) Arsenic
