Glycolysis/Gluconeogenesis/PPP

Question 1

What is the best indicator of ATP use?

Answer 1

AMP levels

Question 2

What are the two highest energy phosphates?

Answer 2

• Creatine Phosphate

- Phosphoenol pyruvate

Question 3

What is the first step of Glycolysis?

What enzyme?

Answer 3

Glucose + ATP —> G6P + ADP

• Hexokinase or Glucokinase

Question 4

Describe the location and significance of Hexokinase D/ Glucokinase.

Answer 4

• Occurs in liver and pancreatic B-cells not inhibited by G6P
• Glucokinase allows cell to capture glucose in high concentrations; In B cells, the G6P signals for insulin secretions while it has many other fates in the liver

Question 5

What is the 2nd step of glycolysis (starting at G6P)?

What enzyme involved?

Answer 5

G6P —> F6P

• Phsphohexose isomerase

Question 6

What is the third step of glycolysis (F6P)?

Enzymes involved?

Answer 6

F6P + ATP —> F1,6 BP

-Phosphfructokinase 1

Question 7

What is the 4th step of Glycolysis (F1,6 BP)?

Enzymes involved?

Answer 7

F1,6 BP —> DHP + G3P

• Aldolase

**ALSO, DHP interconverts with G3P via Triosephosphate isomerase

Question 8

What is the 5th step of glycolysis (start G3P)

Enzymes involved?

Answer 8

G3P + NAD+ + Pi —> 1,3 BPG + NADH

• G3P Dehydrogenase

Question 9

What is the 6th/7th step of glycolysis (start 1,3 BPG)

Enzymes involved?

Answer 9

1,3 BPG + ADP —> 3 Phosphglycerate —> 2- Phsphoglycerate

• Phosphoglycerate kinase
• Phisphoglyerate mutase

Question 10

What are the final 2 steps of glycolysis?

Enzymes involved?

Answer 10

2PG —> Phosphpyruvate H2- —> Pyruvate

• Enolase
• Pyruvate Kinase

Question 11

What are the three primary controls of glycolysis?

Answer 11

Hexokinase
Phosphofructokinase
Pyruvate Kinase

Question 12

What are the positive and negative controls of PFK1?

Answer 12

Positive:

• AMP
• F2,6BP

Negative

• ATP
• Citrate
• Phophatase

Question 13

What are the controls of Pyruvate kinase?

Answer 13

Positive:
- F1,6, BP

Negative:

• Phosphorylation via cAMP Protein kinase
• ATP

Question 14

What is the GFAT pathway?

Answer 14

F6P —> Glucosamine 6-phosphate

• Converts glutamine to glutamate
• Studies show pathway has regulatory functions relating energy expenditure to intake

Question 15

What are common metabolic syndromes associated with fructose?

Answer 15

• Fructokinase deficiency —> Fructosuria

- Aldoase B def —> Hepatic accumulation of F1P

Question 16

Where does GNG occur?

Answer 16

• Liver
• Kidney during starvation
• Within Mt, cytosol, and E.R

Question 17

What are the enzymes used in GNG to bypass irreversible enzymes of glycolysis?

Answer 17

• Glucose 6-phosphatase
• Frustose 1,6 Biphophatase
• PEP carboxykinase
• Pyruvate carboxylase

Question 18

What are the essential allosteric effectors for pyruvate carboxylase?

Answer 18

Biotin

Acetyl CoA

Question 19

What are the two main products of the pentose phosphate pathway?

Answer 19

• NADPH

- Ribose 5-phosphate

Question 20

What is the pathway from G6P to nucleotide synthesis in the PPP?

Related enzymes?

Answer 20

G6P —> 6-Phosphogluconate + NADPH—> Ribulose 5-phosphate + CO@ + NADPH

• glucose 6-phosphate dehydrogenase
• 6-PG dehydrogenase

*Makes 2 NADHPs

Question 21

What is the role of transketolase in the PPP?

Answer 21

• Interconverts molecules to go through either nucleotide synthesis or glycolysis
• Can be either oxidative or nonoxidative

Question 22

What is the cofactors for transketolase?

Answer 22

Thiamin

Question 23

What is Favism??

Answer 23

Possible fatal hemolytic anemia in resin with G6Phosphatase dehydrogenase deficiency