Glycolysis Flashcards
What are the 3 stages of energy generation from food?
1) large cules broken down in digestion
2) small cules processed into key cules of metabolism, esp. acetyl coA
3) ATP produced from complete oxidation of acetyl coA
how is lactase converted to gluc and gal?
lactase (beta-galactosidase)
how is sucrose converted to gluc and fruc?
invertase
maltose is converted to ____ when glucose is low
glucose (done by maltase)
Where is GLUT2 found?
in the liver and pancreatic beta cells
what does GLUT2 do?
pancreas: regulation of insulin
liver: remove excess gluc from blood
- basically, gluc transport
where is GLUT4 found?
in muscle and fat cells
what does GLUT4 depend on to be activated?
insulin
Amounts of ____ increase in muscle plasma membrane with endurance training
GLUT4
pyruvate becomes lactate in which cells?
contracting muscle, erythrocytes
pyruvate becomes ethanol and CO2 in:
yeast
This type of enzyme transfers phosphoryl groups
kinase
diffs between muscle and liver hexokinase?
muscle: hexokinase 1, non-specific, 0.1mM Km, inhibited by Gluc 6P
liver: hexokinase 4, specific, 5-10 mM, not inhibited by Gluc 6P
which enzyme causes the isomerization of G6P to F6P?
phosphoglucose isomerase
what enzyme causes interconversion between aldo and keto sugars?
isomerase
what happens in G6P–>F6P isomerization?
the carbonyl oxygen moves from C1 to C2, turning aldose to ketose sugar
What enzyme catalyzes phosphorylation of F6P to F1,6-BP?
phosphofructokinase (PFK1)
-SUPER IMPORTANT
inhibition of reaction velocity due to negative feedback of high ATP can be overcome by high [ ] of ___
F6P
Which enzyme turns F1,6-BP into DHAP and GAP?
Aldolase, which cleaves the C-C bond
how does DHAP become GAP?
triose phosphate isomerase makes ketose sugar into aldose sugar
which enzyme catalyzes GAP–>1,3-BPG?
glyceraldehyde3P dehydrogenase
Dehydrogenases catalyze ___ reactions
redox
what are the two steps of GAP–>1,3BPG?
1) aldehyde oxidized to carboxylic group
2) phosphate added to carboxylic group
what is the term for a cule connected to a carboxylate group?
acyl
which kinase catalyzes a reversible rxn?
phosphoglycerate kinase
1,3BPG–>3PG is an example of ____phosphorylation
substrate level
in which rxn is first ATP produced?
1,3BPG–>3PG
what enzyme catalyzes 3PG–>2PG?
phosphoglycerate mutase
what type of enzyme transfers groups within molecules?
mutase
what enzyme catalyzes dehydration of 2PG to PPP?
Enolase
PPP is sensitive to which element?
fluoride
PPP–>Pyruvate by which enzyme?
pyruvate kinase
how many ATP equivalents are produced in glycolysis?
7
phosphorylated intermediates have a ___ charge, making them ____ to membranes
negative; impermeable
pyruvate carboxylase requires the vitamin ___ as TPP prosthetic group, and a ____
thiamin (B1); divalent cation
methyl group + carboxylate + ketone =
pyruvate
in fermentation, NAD+ is regenerated by ___
alcohol dehydrogenize
what is the intermediate between pyruvate and ethanol?
acetaldehyde
TPP has a ____ ring, which contains the active centre
thiazolium
pyruvate becomes lactate by the enzyme ___-
lactate dehydrogenase
this enzyme is found only in the liver and phosphorylates C1 only
fructokinase
what enzyme catalyzes F1P–>glyceraldehyde and DHAP in the liver?
F1P-aldolase
which enzyme phosphorylates glyceraldehyde in fructose metabolism in the liver?
triose kinase
what does fructose in adipose tissue become?
F6P
how is galactose converted into G6P?
galactokinase phosphorylates at C1,
metabolism of galactose requires a continuous supply of:
UDP glucose
how does Gal1P become UDP galactose?
galactose1P Uridyl transferase gives glucose the phosphate and gal the UDP (switch)
UDP gal becomes UDP gluc with this enzyme
UDP galactose 4 epimerase
after UDP-Gluc becomes Gluc1P, how does it become G6P?
through the enzyme phosphoglucomutase
condition where galactose is converted to galactitol, causing cataracts, retardation and tissue enlargement
galactosemia
another name for lactose intolerance
hypolactasia
what is the inhibitor of hexokinase?
G6P
what are the activators of PFK1?
AMP and F2,6BP
what are the inhibitors of PFK1?
ATP and citrate
what are the activators of Pyr Kinase?
F1,6BP
what are the inhibitors of Pyr. kinase?
ATP, acetyl coA, fatty acids
acetyl coA is vital in the synth of :
a.a.. ketone bodies, cholesterol, and fatty acids
