02: Carbohydrate Metabolism: Glycolysis and Gluconeogenesis - Study Notes

which glut transporter target brain

1,3,6

which glut only transport fructose

5

which glut transporter target brain

1,3,6

which glut only transport fructose

5

Glycolysis: One molecule of glucose (precursor; 6 carbon atoms) is broken down (through many steps) to finally yield _____molecules of pyruvic acid

two

Glycolysis is a ___ process

catabolic

the payoff phase yields:

• energy conserved as _____

• 2 pyruvate

2 ATP and 2 NADH

Fructose 1,6-bisphosphate is broken down into

G3P and DHAP

____ molecules of G3P are produced from one molecule of glucose

Two

Energetics of Glycolysis

• Energy Investment Phase: ______ molecules are used to initiate glycolysis

2 ATP

Energetics of Glycolysis:

• “Payoff” Phase: 2 ATP molecules are produced from one molecule of ______

3-PG

Energetics of Glycolysis:

• “Payoff” Phase :______molecules are produced from one molecule of glucose

4 ATP

Energetics of Glycolysis:

• “Payoff” Phase: ______ molecules are created and enter the Electron Transport Chain

• Assuming aerobic conditions

• = ___ ATP

2 NADH, 6 ATP

Increases the conversion of glucose to pyruvate by activating enzymes of step 1, 3, and 10

hexokinase, Phosphofructokinase, Pyruvate kinase

In anerobic respiration, pyruvate is reduced to lactate by ________ (enzyme)

• Ketone (Pyruvate) is reduced to an alcohol (lactate)

lactate dehydrogenase

Alternate fates of Pyruvate

• Oxidative decarboxylation of pyruvate to _____

acetyl CoA

Alternate fates of Pyruvate

• Carboxylation of pyruvate to

OAA

Alternate fates of Pyruvate

• Reduction of pyruvate to ______

ethanol

______: Synthesis of glucose from non-carbohydrate precursors

• Does not occur in the muscle, nerve cells

Gluconeogenesis

The analogous “reverse” reaction in glycolysis was catalyzed by______

PFK-1

Fructose-2,6-bisphosphate ______ PFK-1 (glycolysis)

activates

Fructose-2,6-bisphosphate ______ fructose 1,6-bisphosphatase (gluconeogenesis)

inhibit

The release of free glucose from glucose 6-phosphate occurs only in the ____ and _____

• Gluconeogenesis does not occur in the muscle

• Muscle lacks glucose 6-phosphatase

liver. kidney

Gluconeogenesis is an _____ process

anabolic

______ are used in gluconeogenesis

4 ATP, 2 GTP, 2 NADH

______ are produced in glycolysis In the payoff phase

4 ATP, 2 NADH

PFK-1: ____ by AMP

activated

FBPase-1: ____ by AMP

inhibited

_____ (aka Lactic Acid Cycle): The combination of glucose transport to actively working tissues, and the reverse transport of lactate from those tissues back to the liver

• Useful to sustain glucose levels when glucose is unavailable

  • e.g. overnight fasting, starvation

Cori Cycle