Metabolism Midterm Focused Cram

Dr. Jones LLU

Classic galactosemia

Galactose 1-phosphate buildup- avoid lactose

Hereditary fructose intolerance

Fructose 6-phosphate builds up- avoid fructose (no sugar, no fruit)

Pyruvate carboxylase needs…

B7

What enzyme is used for pyruvate to lactate?

lactate dehydrogenase

Pentose phosphate pathway makes…

ribose and NADPH (use in anabolic reactions)

G6PD deficiency

not enough NADPH → hemolytic anemia

x-linked recessive

due to oxidative stress

What regulates G6PD in PPP

insulin +

What regulates FBP1

F2,6BP

What regulates glycogen synthase (a1,4)

covalently regulated by insulin +

What regulates glycogen phosphorylase

glucagon +, insulin -

How do we regulate glucokinase?

If fructose 6-phosphate builds up, glucokinase builds up in nucleus

How do we regulate PFK-1?

PFK-1 is allosterically activated by fructose-2,6-bisphosphate (made from F6P by PFK-2) and inhibited by ATP and citrate.

How are FBP2 and PFK2 regulated?

insulin and glucagon

What is ATP production called when ATP is made directly from a metabolic intermediate?

Substrate-level phosphorylation

How does glucagon regulate PFK-1?

Allosterically: + F2,6BP, AMP, – ATP, citrate

What transports glucose and galactose?

SGLT-1

What transports fructose?

GLUT-5

Glucose, galactose, and fructose exit w/…

GLUT2

After exiting through GLUT2, glucose, galactose, and fructose enter the ___, → ____

portal vein, liver

What is the most important rate-limiting enzyme in glycolysis?

PFK-1

In aerobic conditions: pyruvate enters ___ an is acted on by the ____, makes ___, ___, and ___

mitochondria, pyruvate dehydrogenase complex, Acetyl-CoA, CO2, and NADH

E1: coenzyme and vitamin

TPP- thiamin

E2:

lipoic acid, CoA- pantothenic acid/B5

E3:

FAD (riboflavin), NAD+ (niacin)

1 molecule makes ____ in the TCA cycle, 1 cycle makes ____

6 NADH, 3 NADH

How is a-ketoglutarate dehydrogenase regulated?

NADH -, succinyl CoA -

How is isocitrate dehydrogenase regulated?

NADH and ATP

ATP per electron pair ETC

NADH → O2: 2.5 ATP/NADH

FADH2 → O2: 1.5 ATP/FADH2

What atom gradient is created to generate in the ETC?

hydrogen ikon gradient (H+) (AKA proton gradient)

What molecule is at high concentrations within the ETC?

H+ (protons)

What is a byproduct of the ETC?

H2O

ATP equivalent of NADH

2.5 ATP

ATP equivalent of FADH2

1.5 ATP

Which enzyme splits fructose in metabolism?

Aldolase B