Studied by 0 people
Looks like no one added any tags here yet for you.
Metabolic pathways can be “swiched on and off” in three main ways
controlling the amount of enzymes
allosteric control of the enzyme (binding other than active site)
covelent modifcation of the enzyme
controlling the amount of enzymes
depends on its particular rate of synthesis and rate of degradation usualy adjusted by changing the rate of transcription of the gene coding for the enzyme
Allosteric control of the enzyme
Binding of a metabolite to the allosteric site of some enzymes can lead to allosteric activation which increases enzyme activity.
Binding of a metabolite to the allosteric site of other enzymes can lead to allosteric inhibition which decreases enzyme activity.
feed-forward activation
where a metabolite early in the pathway activates an enzyme further down the pathway.
feedback inhibition
where the product of a pathway inhibits the rate of its own synthesis by inhibiting an early step in the pathway
Revesable covelant modifaction
is a regulatory mechanism where the activity of an enzyme is altered by the addition or removal of a chemical group, such as a phosphate group, which can activate or deactivate the enzyme.
Phosphorylation
carried out by the enzyme kinases
dephosphorylation
carried out by the enzyme phosphates
reasons why ATP has a high phosphoryl transfer potential
Respnance stabalization
electrostatic repulsion
stabilization due to hydration
stage 1 of glycolysis
energy investment phase of glycolysis
stage 2
energy yeilding phase of glycolysis where ATP is produced.
kinases
adds or removes phosphoryl groupto a molecule.
Hextokinase
Adds phosphoryl group to glucose
Isomerases
Rearranges atoms in the molecule without altering its molecular formulato create different isomers.
Aldolase
make or break carbon-carbon bonds
Dehydrogenases
transfers of hydride ion to an electron acceptor nad+ in glycolysis
Enolase
Adds double bond by dehydration reaction
Mutase
Catalzes intramolecular shift of a group
Note 
Flashcard (28)