Diseases related to glycolysis

Question 1

Three types of lactose intolerance?

Answer 1

Primary lactase deficiciency, secondary lactase deficiency and congenital lactase deficiency

Question 2

Describe what primary lactase deficiency is

Answer 2

Absence of lactase persistence allele
so lactase is only produced in childhood
So only occurs in adults

Question 3

Describe what secondary lactase deficiency is

Answer 3

Caused by injury to the small intestine eg. Gastroenteritis,
coeliac disease,
Crohn’s disease,
Ulcerative colitis

Generally reversible

Question 4

Describe what congenital lactase deficiency is

Answer 4

Autosomal recessive defect in lactase gene

Cannot digest breast milk

Question 5

How can glycolysis be used in a clinical setting?

Answer 5

Rate of glycolysis up to 200 times greater in cancer
Can measure up take of chemicals (radioactive modified hexokinase substrate)
Used in PET scans

Question 6

How can the conversion of lactose to glucose in the liver be impaired? (4)

Answer 6

Liver disease
Thiamine deficiency
alcohol (NAD+ –>NADH)
Enzyme deficiencies

Question 7

WHat 3 ways is the plasma lactate concentration determined (By the rates of what?

Answer 7

Production
Utilisation in the liver and heart
Disposal (Kidney)

Question 8

Above what value is a patient considered to be in lactic acidosis?

Answer 8

5mM

Question 9

What is the danger of lactic acidosis?

Answer 9

Lower blood pH affects functioning of brain and heart

Question 10

Describe what essential fructosuria is?

Answer 10

Fructokinase is missing

Fructose in the urine

Question 11

Describe the mechanism behind fructose intolerance and treatment

Answer 11

Aldolase is missing
Fructose 1P accumulates in the liver–>Liver damage
treatment- remove fructose from diet

Question 12

What does aldolase do?

Answer 12

Converts fructose 1P to glyceraldehyde and DHAP

Question 13

What are the symptoms of galactosemia? (8)

Answer 13

Hepatolmegaly and cirrhosis
Renal failure
Vomiting
Seizure and brain damage
Cataracts
Hypoglycaemia

Question 14

Describe how galactosemia leads to cataracts

Answer 14

Galactose builds up
Galactose is converted to galactitol by aldose reductase

Increased aldose reductase activity converts excess NADPH–>NADP+

NADPH is used in the defence against oxidative damage, so reduced NADPH will cause the crystallin protein inn the lens of the eye to be denatured, so leads to cataracts

Question 15

Note see the glycolysis group work presentation for oxidative stress

Answer 15

a