Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Biochemistry Exam 2 > Gluconeogenesis > Flashcards

Gluconeogenesis Flashcards

1
Q

The whole body needs _____ grams of glucose per day

A

160

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

The daily glucose requirement of the brain is ____ grams

A

120

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Glucose present in body fluids is ____ grams

A

20

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Glucose readily available from glycogen is ____ grams

A

190

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

How long can you go without ingesting glucose to where your glucose reserves can compensate?

A

One day

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

_______ is especially important for during longer periods of fasting or starvation

A

Gluconeogenesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What organs does gluconeogenesis occur?

A

Liver and Kidneys

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is Gluconeogenesis?

A

Synthesis of glucose from non-carbohydrate precursors

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Is gluconeogenesis a reversal of glycolysis?

A

No, because different enzymes catalyze the reactions and oxaloacetate is used in gluconeogenesis whereas it is not found in glycolysis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the overall process of gluconeogenesis? (first and last molecule)

A

Pyruvate into glucose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are the 3 major precursors of gluconeogenesis?

A

Lactate
Amino acids
Glycerol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Gluconeogenesis _____ the irreversible steps of glycolysis

A

Bypasses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How does gluconeogenesis bypass the irreversible steps of glycolysis?

A

Through the 4 enzymes not present in glycolysis:

Pyruvate Carboxylase
Phosphoenolpyruvate Carboxykinase
Fructose 1,6-Bisphosphatase
Glucose 6-Phosphatase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Where does gluconeogenesis first occur?

A

In the mitochondria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How does gluconeogenesis transition from beginning in the mitochondria to the cytoplasm

A

Pyruvate is in the mitochondria and converts to oxaloacetate, which converts to Malate. This can leave the mitochondria via the Malate Shuttle and re-convert back to oxaloacetate in the cytoplasm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

List the steps of gluconeogenesis

A

Pyruvate is converted into oxaloacetate by pyruvate kinase

OAA is converted into phosphoenolpyruvate by phosphoenolpyruvate carboxykinase

phosphoenolpyruvate is converted to 2-Phosphoglycerate by enolase

2-Phosphoglycerate is converted into 3-Phosphoglycerate by phosphoglycerate mutase

3-Phosphoglycerate is converted into 1,3-Bisphosphoglycerate by Phosphoglycerate kinase

1,3-Bisphosphoglycerate is converted into Glyceraldehyde 3-phosphate by G3P dehydrogenase

G3P converts to Fructose 1,6-bisphosphate by Aldolase

Fructose 1,6-bisphosphate converts to Fructose 6 phosphate by Fructose 1,6 bisphosphatase

Fructose 6 phosphate converts to Glucose 6 phosphate by phosphoglucokinase

G6P is converted into Glucose by Glucose 6 phosphatase

17
Q

Where is Glucose 6 phosphate located?

A

in the lumen of the ER

18
Q

What 3 proteins are used to shuttle glucose/G6P and what does each specifically do?

A

T1- transports Glucose-6-Phosphate to ER
T2-transports inorganic phosphate back
T3-transports free Glucose back to the cytoplasm

19
Q

Glycolysis ____ ATP, Gluconeogenesis ____ ATP

A

Generates

Consumes

20
Q

Gluconeogenesis and Glycolysis are ______ ______

A

reciprocally regulated

21
Q

When is glycolysis favored?

A

When blood [insulin] is high

22
Q

When is gluconeogenesis favored?

A

When blood [glucose] levels are low and glycogen stores are depleted

23
Q

Where does glycolysis occur? Tissue and subcellular

A

RBCs, exercising muscles, brain, cytosol

24
Q

Where does gluconeogenesis occur? Tissue and subcellular

A

Liver (mostly), kidneys, and small intestines

Subcellular: mitochondria and cytosol

25
Q

What are the positive regulators of glycolysis?

A 
Glucose
Insulin
AMP
Fructose 2,6-Bisphosphate
Fructose 1,6 Bisphosphate
26
Q

What are the positive regulators of gluconeogenesis?

A 
Glucagon
Citrate
Cortisol
Thyroxine
Acetyl CoA
27
Q

What are the negative regulators of glycolysis?

A 
Glucagon
ATP
Citrate
G6P
Fructose 6 Phosphate
Alanine
28
Q

What are the negative regulators of gluconeogenesis?

A

ADP
AMP
Fructose 2,6-bisphosphate

29
Q

Describe the energy usage and yield of glycolysis

A

Use: 2 ATP
Yield: 4 ATP
Net Yield: 2 ATP/glucose oxidized

30
Q

Describe the energy usage and yield of gluconeogenesis

A

Use: 4 ATP, 2 GTP
Yield: 0
Net Yield: 6 ATP Equivalents/glucose oxidized

31
Q

In the ______, rates of glycolysis and gluconeogenesis are adjusted to maintain blood glucose

A

Liver

32
Q

_______ strongly stimulates Phosphofructokinase and inhibits Fructose 1,6- bisphosphatase

A

Fructose 2,6-bisphosphate

33
Q

What 2 enzymes regulate the conc. of Fructose 2,6- bisphosphate

A 
Phosphofructokinase 2 (PFK2)
Fructose Bisphosphatase 2 (FBPase2)
34
Q

What is the Corri Cycle?

A

Lactate produced in skeletal muscle and RBCs can be converted back to pyruvate in the liver

The pyruvate can enter the gluconeogenesis pathway and regenerate glucose (which is the source of lactate)

35
Q

What is generated by the action of pyruvate carboxylase?

A

Oxaloacetate

36
Q

What enzyme is the gluconeogenesis partner of phosphofructokinase?

A

Fructose 1,6 bisphosphatase

37
Q

What is the most important substrate of the Corri Cycle?

A

Lactate

Biochemistry Exam 2 (13 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions