Gluconeogenesis Flashcards Preview

My NBCE - Biochemistry - Carbohydrate Metabolism > Gluconeogenesis > Flashcards

Flashcards in Gluconeogenesis Deck (44)
Loading flashcards...
1

Gluconeogenesis is _______ synthesis of glucose.

De novo

2

Gluconeogenesis is synthesis of glucose form __________ substrates.

non-carbohydrate

3

What are some of the non-carbohydrate substrates used in Gluconeogenesis.

Pyruvate
Glycerol from adipose tissue
glucogenic amino acids from muscle protein

4

Enzymes for Gluconeogenesis are found where?

Only in liver, kidney, and intestinal epithelium

5

Gluconeogenesis main occurs where?

Cytosol of liver cells

6

During prolonged starvation what becomes the major glucose producing organs?

kidneys

7

When glucose is not available what does the brain use for fuel?

ketones

8

When does gluconeogenesis occur?

Durian fasting, starvation, or intense exercise

9

Gluconeogenesis is highly ________. (energy requiring)

endergonic

10

Can humans make glucose from acetyl CoA?

NO

11

Glucokinase is replaced by which enzyme?

Glucose-6-phosphatase

12

PFK is replaced by which enzyme?

Fructose-1,6-bisphosphatase

13

Pyruvate kinase is replaced by which enzyme?

Pyruvate carboxylase and PEP carboxykinase

14

What is the common substrate for gluconeogenesis?

Lactate/lactic acid

15

Lactic acid is converted into _______ by which cycle?

pyruvate
Cori cycle

16

What enzyme is used to convert lactate to pyruvate?

Lactate dehydrogenase

17

What is the glucogenic amino acid that can convert to pyruvate?

alanine

18

The Cori cycle comes at a net loss of how many ATP?

4

19

What does the Cori cycle do?

Prevents lactic acid from building up in the muscles.

20

The first step of gluconeogenesis occurs where?

mitochondrion

21

The rest of gluconeogenesis (not 1st step) occurs where?

cytosol

22

What enzyme converts pyruvate to oxaloacetate? This occurs where?

Pyruvate carboxylase
Mitochondrion (1st step)

23

What is the essential coenzyme for the 1st reversal step? (pryruvate to oxaloacetate)?

biotin (B7)

24

A biotin deficiency will cause what to build up resulting in excess production.

lactate

25

What are allosteric activators of the 1st reversal step in gluconeogenesis?

ATP and Acetyl CoA

26

What is the second part reversal?

Oxaloacetate to phosphoenolpyruvate

27

What enzyme is used in the second step?

PEP carboxylase

28

Where does the second step occur?

cytoplasm

29

PEP carboxylase is facilitate by what?

Glucagon and cortisol

30

Is lots of energy needed for step two reversal?

yes