Glycolysis Flashcards
is glycolysis active with high or low blood sugar?
active with high sugar
does insulin inhibit or promote glycolysis?
promotes
what is end product of glycolysis?
2 pyruvates
where does glycolysis occur in the cell?
in cytoplasm
if aerobic situation, what is pyruvate turned into?
acetyl coa
if anaerobic situation, what is pyruvate turned into?
lactate
name the four glucose transporters
GLUT 1234
where is Glut 1 found
most all cells
where is Glut 2 found
liver/pancreas
what is special about GLUT 2 fxn?
bidirectional transport, active at high levels
where is Glut 3 found
neurons/placent
where is Glut 4 found
muscle fat cells
what induces glut 4?
insulin
what two enzymes in glycolysis use ATP?
hexokinas/glucokinase
PFK-1
what does hexokinase react with and make?
reacts with glucose to make glu 6 P
what does PFK 1 react with and make?
reacts with fru 6 P and makes Fru 1,6 P
what is the rate limiting enzyme of glycolysis?
PFK-1
what induces and what inhibits PFK-1
ATP inhib ADP induce
what inhibits hexokinase?
Glu-6-P
what is a relative of PFK-1 enzyme that has regulatory effect on glycolysis?
PFK-2
explain the role of PFK-2 in glycolysis
insulin activates it and leads PFK-2 to convert fructose-6-P into fructose-2,6-P
what is the role of fructose 2,6-P in glycolysis?
activates PFK 1 and feeds rxn forward
how does alcohol inhibit glycolysis?
increases NADH levels
what is the net ATP prdxn of glycolysis?
2 ATP
why is net ATP only 2 in glycolysis?
2 are used early and 4 are made late (2 by each GAP)
what disaccharide has galactose in it?
lactose…galactose and glucose
where does galactose fit into glycolysis pathway?
feeds in at glu-6-P
what is enzyme of first step of galactose breakdown?
galactokinase
what does galactokinase react with and make?
reacts with galactose to make galactose-1-P
what is second enzyme in galactose breakdown>
galactose 1 phosphate uridyltransferase
what is issue in classic galactosemia?
decreased activity of galactose 1 P uridyltransferase
what accumulates in classic galactosemia?
increased galactose and galactose 1-P
what can galactose cause with eye in high amounts?
cataracts
what is issue in non classical galactosemia?
galactokinase decreased activity
what builds up in classical galactosemia?
galactose only
why is classic galactosemia worse than non classic?
in classic you burn up all your ATP with glucokinase rxn
where does fructose enter glycolysis?
as GAP
what is GAP?
glyceraldehyde phosphate
what is first step in fructose breakdown path?
fructokinase turns fructose into fructose -1-P
what is second step in fructose breakdown path?
fru-1-P into glyceraldheyde via aldolase B
what is issue in fructose intolerance?
aldolase B is deficient and you get buildup of fru-1-P and overuse of ATP
what is issue in essential fructosuria?
fructokinase is a problem and fructose builds up but ATP not overused
