Enzymes Week 4 German Flashcards
What 3 things to Enzymes do?
- Increase chemical rxn rate
- reduce free energy needed for rxn
- increase probability of rxn occurrence
what is a holoenzyme?
a complete catalytically active enzyme w/ coenzymes and cofactors.
what is a cofactor?
inorganic ions
Enzyme mechanism
covalently change chemical structure
shift substrates into the transition state
weak binding is optimal in the transition state
weak bonding releases free energy
weak binding drives enzyme catalysis
Are enzymes complementary to substrate shapes or to the transition state of the substrate?
transition state of the substrate
how do enzymes overcome entropy of molecules in a solution?
utilizing binding energy to organize substrates, and reduce entropy
how do enzymes overcome solvation shells?
by the weak bonds desolvate substrates aka move the water out of the way of the active site
how do enzymes overcome alter substrate conformation?
weak bonds alter the substrate confirmation
how do enzymes overcome substrate orientations?
have the shape of transition state and thus an induced fit to the substrate
What is an allosteric enzyme?
an enzyme thats conformation is changed by effector binding (positive modulator)
Do allosteric enzymes follow Machaelis-Menton kinetics?
NOPE
ways allosteric enzymes are post translationally modified
covalent modification via: phosphorylation, methylation, myristoylation, acetylation
What is a homotropic regulated allosteric enzyme?
its own substrate regulates enzyme function
What is a heterotropic regulated allosteric enzyme?
a non-substrate molecule regulates enzyme function
