Gluconeogenesis/Pentose Phosphate Shunt

Question 1

What are the 4 irreversible enzymes in gluconeogenesis?

Answer 1

Pyruvate carboxylase
Phosphoenolpyruvate carboxykinase
Fructose-1,6- bisphosphatase
Glucose-6- phosphatase

Pathway Produces Fresh Glucose.

Question 2

Gluconeogenesis occurs primarily in the _____? Where else do you find gluconeogenic organs?

Answer 2

Liver

Kidney* and intestinal epithelium

Question 3

Muscle cannot participate in gluconeogensis because?

Answer 3

It does not have glucose-6 phosphate

Question 4

Which chains of fatty acids can enter in the TCA cycle? Why?

Answer 4

Odd chain because they yield 1 propionyl-coA which acts as succinyl-coA

Question 5

In the Pentose Phosphate Pathway, how many ATP is used and produced? What is the goal of Pentose phosphate pathway (2 things)? What are each used for?

Answer 5

Zero

1. Produce NADPH
   - for anabolic rxns (i.e. fatty acid synthesis, glutathione reduction) and antioxidant
2. Produce Ribose 5 phosphate (DNA synthesis)

Question 6

In what part of the cell does the Pentose Phosphate Pathway occur? In which organs does it occur?

Answer 6

Cytoplasm

Mammary glands (fatty acid/milk), Liver (fatty acid, glutathione), Adrenal Cortex (fatty synthesis/steroid), RBCs (glutathione)

“Keep CALM and oxidize”

Cells (RBCs), Adrenal Cortex, Liver, Mammary Glands

Question 7

What is the non-oxidative part of Pentose phosphate pathway supposed to do? What enzyme is used and what vitamin is required?

Answer 7

Make other sugars

Transketolase
Thiamine (B1;TPP)

Question 8

In G6PD def, decreased NADPH levels will lead to what kind of anemia? Why?

Answer 8

Hemolytic

Decreased NADPH=> increased free radicals

Question 9

Give examples of things that will exacerbate a patient’s anemia in G6PD def.?

Answer 9

Antimalarial 
Sulfonamides
Anti-TB drugs
Fava beans
Infection

“Bite Cells and Heinz Ketchup BITeS Me”

Beans (Fava)
Infection
TB drugs
Sulfonamides
Malarial drugs

Question 10

How are free radical generated in an infection? These free radicals are normally neutralized by what enzymes?

Answer 10

Via inflammatory responses

Glutathione reductase and Glutathione peroxidase

Question 11

G6PD has what kind of inheritance? It is the MC what? It is increased in what population and this population have resistance to?

Answer 11

X-linked

Human enzyme def.

Blacks

Malaria

Question 12

Heinz bodies are what? Who creates the bite cells?

Answer 12

denatured hemoglobin in RBCs due to oxidative stress.

Splenic macrophages