Fructose And Galactose Metabolism

Question 1

Dietary source of fructose

Answer 1

Fruits honey corn syrup

Question 2

Fructose metabolism pathway

Answer 2

Phosphorylation of Fructose by hexokinase or fructokinase to form fructose1 pi

Cleavage of fructose 1 pi by aldolase B to form dihydroxyacetone pi and glyceraldehyde 3 pi

Question 3

Dietary source of galactose

Answer 3

Lactose from milk

Question 4

Galactose metabolism pathway

Answer 4

Galactokinase convers galactose to galactose 1 pi

UDP glucose and galactose 1 pi react and form => glucose-1-pi and UDP galactose

Phosphoglucomutase transform glucose 1 pi to glucose 6 pi which continue glycolysis or form glucose

Question 5

Mode of absorption of fructose

Answer 5

Simple Facilitated diffusion

Question 6

Is fructose and galactose intake insulin dependent?

Answer 6

No

Question 7

Location in the body of fructose metabolism

Answer 7

Liver

Question 8

Different fate of fructose metabolism

Answer 8

Dihydroxyacetone to form glucose or glycogen

Glyceraldehyde to form glyceraldehyde 3 pi to enter glycolysis pathway and TCA cycle

Glyceraldehyde can for glycerol and produce lipids

Glyceraldehyde can produce serine

Question 9

When is hexokinase acting fructose

Answer 9

When hike a centration of fructose

Question 10

Hereditary fructose intolerance

Answer 10

Fructose toxicity due to sequestering of phosphate and depletion of ATP because of

aldolase b deficiency with F1P accumulation

Question 11

Symptoms of disorders of fructose metabolism

Answer 11

Severe hypoglycemia 
Vomiting when fructose intake 
Poor feeding 
Hepatomegaly 
Jaundice 
Kidney damage 
Hepatic failure 
Death

Question 12

Treatment of fructose toxicity

Answer 12

Remove sucrose/fructose from diet ( fruits , juices, cakes , ice creams, honey )

Question 13

Fructosuria

Answer 13

Fructokinase lacking

Benign

Question 14

Galactosemia disorders

Answer 14

Non classical -> galactokinase deficiency

Classical -> GALT deficiency