Gluconeogenesis

Question 1

Gluconeogenesis is _______ synthesis of glucose.

Answer 1

De novo

Question 2

Gluconeogenesis is synthesis of glucose form __________ substrates.

Answer 2

non-carbohydrate

Question 3

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

Answer 3

Pyruvate
Glycerol from adipose tissue
glucogenic amino acids from muscle protein

Question 4

Enzymes for Gluconeogenesis are found where?

Answer 4

Only in liver, kidney, and intestinal epithelium

Question 5

Gluconeogenesis main occurs where?

Answer 5

Cytosol of liver cells

Question 6

During prolonged starvation what becomes the major glucose producing organs?

Answer 6

kidneys

Question 7

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

Answer 7

ketones

Question 8

When does gluconeogenesis occur?

Answer 8

Durian fasting, starvation, or intense exercise

Question 9

Gluconeogenesis is highly ________. (energy requiring)

Answer 9

endergonic

Question 10

Can humans make glucose from acetyl CoA?

Answer 10

NO

Question 11

Glucokinase is replaced by which enzyme?

Answer 11

Glucose-6-phosphatase

Question 12

PFK is replaced by which enzyme?

Answer 12

Fructose-1,6-bisphosphatase

Question 13

Pyruvate kinase is replaced by which enzyme?

Answer 13

Pyruvate carboxylase and PEP carboxykinase

Question 14

What is the common substrate for gluconeogenesis?

Answer 14

Lactate/lactic acid

Question 15

Lactic acid is converted into _______ by which cycle?

Answer 15

pyruvate

Cori cycle

Question 16

What enzyme is used to convert lactate to pyruvate?

Answer 16

Lactate dehydrogenase

Question 17

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

Answer 17

alanine

Question 18

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

Answer 18

4

Question 19

What does the Cori cycle do?

Answer 19

Prevents lactic acid from building up in the muscles.

Question 20

The first step of gluconeogenesis occurs where?

Answer 20

mitochondrion

Question 21

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

Answer 21

cytosol

Question 22

What enzyme converts pyruvate to oxaloacetate? This occurs where?

Answer 22

Pyruvate carboxylase

Mitochondrion (1st step)

Question 23

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

Answer 23

biotin (B7)

Question 24

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

Answer 24

lactate

Question 25

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

Answer 25

ATP and Acetyl CoA

Question 26

What is the second part reversal?

Answer 26

Oxaloacetate to phosphoenolpyruvate

Question 27

What enzyme is used in the second step?

Answer 27

PEP carboxylase

Question 28

Where does the second step occur?

Answer 28

cytoplasm

Question 29

PEP carboxylase is facilitate by what?

Answer 29

Glucagon and cortisol

Question 30

Is lots of energy needed for step two reversal?

Answer 30

yes

Question 31

What is the rate limiting step of gluconeogenesis?

Answer 31

Step 3 reversal: fructose-6-phosphate from fructose 1,6-bisphosphate

Question 32

What is the enzyme for step 3 reversal?

Answer 32

Fructose 1,6- bisphosphatase

Question 33

What stimulates fructose 1,6-bisphosphase?

Answer 33

ATP and citrate

Question 34

What inhibits fructose 1,6--bisphosphatase?

Answer 34

AMP and fructose 2,6-bisphosphate

Question 35

What is the enzyme for step 1 glycolysis reversal?

Answer 35

Glucose-6 phosphatase

Question 36

What does glucose 6-phosphatase do?

Answer 36

coverts glucose 6-phophate into glucose

Question 37

Where is glucose 6-phosphatase located?

Answer 37

ER of liver and kidney cells

Question 38

G6P is ________ as it passes into the ER.

Answer 38

hydrolyzed

Question 39

Gluconeogenesis is inhibited by ______ and stimulated by _______.

Answer 39

insulin | glucagon

Question 40

Gluconeogenesis DOES NOT occur in _____ and the ____.

Answer 40

Muscles | brain

Question 41

Gluconeogenesis is an energy _______ process.

Answer 41

consuming

Question 42

How many ATP does gluconeogenesis use to produce one glucose molecule?

Answer 42

6

Question 43

Why is acetyl CoA not used to make glucose?

Answer 43

Requires more energy than using lactate or alanine

Question 44

If the glucose made is not used immediately, then what happens to it?

Answer 44

Converted and stored as glycogen in liver or skeletal muscle.