Carb Metabolism 2

Question 1

RBCs rely exclusively on what for energy?

Answer 1

glycolysis because they DO NOT HAVE MITOCHONDRIA

Question 2

All the steps of glycolysis :)

Answer 2

:)

Question 3

What enzyme do we use to convert Glyceraldehyde 3 phosphate + NAD –> 1,3 bisphosphoglycerate?

Answer 3

glyceraldehyde phosphate dehydrogenase

Question 4

What enzyme do we use yo convert 1,3 bisphosphoglycerate + ADP –> 3 phosphoglycerate

Answer 4

phosphoglycerate kinase

Question 5

What are the 3 irreversible steps of glycolysis?

Answer 5

1. Glucose + ATP –> hexokinase –> glu 6 phosphate
2. Fruc 6 P + ATP –> PFK 1 –> Fruc 1,6 bisphosphate
3. PEP + ADP –> pyruvate kinase–> pyruvate + ATP

Question 6

Fructose can be used in two different ways (in 2 different areas..) explain

Answer 6

LIVER: Fructose –> fructokinase –> fructose 1 p
Fructose 1 p –> aldolase B –> Glyceraldehyde + DHAP (DHAP GOES TO GLYCOLYSIS)

MUSCLE: Fructose –> hexokinase –> fructose 6 P –> Glycolysis

Question 7

Hexokinase is found where?

Answer 7

muscle

Question 8

Fructokinase is found where?

Answer 8

liver

Question 9

What does Galactose ultimately get broken down into?

Answer 9

Glucose 6 phosphate

Question 10

How do we take UDP-glucose and get it to glucose 1 p? (1 step)

Answer 10

UDP-glucose –> Glu 1 P uridyltransferase–> glucose 1 p

Question 11

What results from a deficiency of liver fructokinase?

Answer 11

essential fructosuria

Question 12

Is essential fructosuria harmful?

Answer 12

no, fructose does not get converted to fruc 1 P and will be excreted in the urine

Question 13

What is hereditary fructose intolerance?

Answer 13

aldolase B defiency, resulting in buildup of fruc 1 P; this can be bad for the liver

Question 14

What happens if aldolase B is deficient?

Answer 14

hereditary fructose intolernance

Question 15

How do you treat hereditary fructose intolerance?

Answer 15

fructose-free diet

Question 16

What are 2 examples of inborn errors of metabolisim?

Answer 16

PKU

Galactosemia

Question 17

What is galactosemia?

Answer 17

a failure to utilize galactose and can be caused by:

1. a mutation in galactokinase
2. galactose 1 phosphate uridyltransferase mutation
3. UDP galactose epimerase mutation

Question 18

How do you convert UDP-galactose –> UDP-glucose?

Answer 18

UDPG4-epimerase

Question 19

What are the 3 regulated enzymes of glycolysis?

Answer 19

1. hexokinase
2. PFK-1
3. pyruvate kinase

Question 20

Hexokinase regulated by?

Answer 20

+ insulin

- gluc 6 P and acetyl-CoA

Question 21

What is the rate limiting step of glycolysis?

Answer 21

PFK-1

Question 22

PFK-1 regulation?

Answer 22

+hormones, ADP, AP

-ATP, citrate

Question 23

Pyruvate kinase regulated by?

Answer 23

+fruc 1,6 bisphosphate, insulin

-ATP

Question 24

A high cAMP concentration signals you are in what state?

Answer 24

fasting state; reducing glucose consumption by glycolysis

Question 25

Draw the fruc 2,6 bisphosphate regulation.

Answer 25

:)

Question 26

What 2 things activate PFK 2?

Answer 26

fruc 6 P

AMP

Question 27

What activates cAMP? What inhibits?

Answer 27

+ glucagon

- insulin

Question 28

PFK 2 is inhibited by what?

Answer 28

PKA

Question 29

What are two shuttles used for NADH? include location

Answer 29

glycerol phosphate shuttle: muscle and brain

malate-aspartate shuttle: liver and heart

Question 30

How much ATP do you get from the glycerol phosphate shuttle and from what agent?

Answer 30

you get 2 ATP from 1 FADH

Question 31

What shuttle is located in the muscle and brain?

Answer 31

glycerol phosphate shuttle

Question 32

How many ATP do you get from malate-aspartate shuttle and from what?

Answer 32

3 ATP from 1 NADH

Question 33

What shuttle is located in the liver and heart?

Answer 33

malate-aspartate

Question 34

Pyruvate gets ______ to lactic acid?

NADH gets ____ to NAD+?

Answer 34

pyruvate gets reduced

NADH gets oxidized

Question 35

What 2 things produce lactate which must be converted back into glucose by the liver?

Answer 35

RBCS and muscles

Question 36

Describe the CORI cycle.

Answer 36

1. Pyruvate gets reduced to lactate in the RBCs/muscles

2. lactate is shuttled to the liver where it is oxidized to pyruvate and then synthesized into glucose

Question 37

What is the most common hereditary enzymatic defect in glycolysis?

Answer 37

pyruvate kinase deficiency: lysis of RBCs

Question 38

Arsenic poisoning?

Answer 38

arsenic mimics phosphate, so when gly 3 p is in the presence of arsenic, it forms a different product and no ATP is produced