Regulation Of Cellular Metabolism

Front 1

flux

Back 1

-rate at which material passes through a pathway (or any of the steps of that pathway)
-turnover of energy/movement of substances

Front 2

enzyme activity

Back 2

-amount of functional enzyme present (in a tissue/solution)
-measured in terms of amount of product produced per unit time (flux) under ideal conditions
-normalized to amount of protein present or amount of tissue

Front 3

determination of enzyme activity

Back 3

-gene expression
-specific modulators
-chemical/physical factors (pH, ionic concentration, temperature)

Front 4

equilibrial reactions

Back 4

-functional enzyme is in sufficient quantity and converts reactant into product very fast
-reaction is always close to equilibrium regardless of flux
-q is close to K
-flux through equilibrial reaction largely determined by availability of reactants and removal of products

Front 5

non-equilibrial reactions

Back 5

-q is very far from equilibrium
-q<<K
-reactants build up and products are removed
-reactants accumulate due to action of reactions upstream from non-equilibrial step... downstream rxns drain much of product

Front 6

importance of enzyme activity

Back 6

-important in non-equilibrial reactions
-not in equilibrial reactions

Front 7

PFK

Back 7

-allosteric enzyme controlling non-equilibrial rxn of phosphate from ATP to glucose-6-P
-inhibited by high [ATP]
-activated by high [AMP]