Session 9 - Nutrient Control Gene Expression

Question 1

What are nucleotides made up of?

Answer 1

Phosphate
A nitrogenous base
Deoxyribose sugar

Question 2

What can be synthesised by de novo pathway?

Answer 2

Purines and pyrimidines

Question 3

What is the first product in the de-novo pathway of purine synthesis?

Answer 3

5 phospo-a-D-ribosyl 1 pyrophsophae (PRPP) PRPP (1st step)

Question 4

Which of the following nutrients is NOT required as cofactor in Purine synthesis?

Answer 4

Manganese

Question 5

What nutrient cofactors are required in Purine synthesis?

Answer 5

Glutamine, Magnesium, Iron, B2, B3, Molybdenum

Question 6

What is the end product of purine metabolism?

Answer 6

Uric Acid

Question 7

Faults in purine metabolism (such as deficiency of enzyme HPRT) may lead to which health risks?

Answer 7

Hyperuricemia
Gout
Kidney Stones

Question 8

What are telomeres?

Answer 8

The non coding sequence at the tail end of a chromosome

Question 9

How are telomere length preserved?

Answer 9

Exercise
Dietary intake of antioxidants
Optimal folate status - low blood folate is associated with shorter telomeres

Question 10

What nutrient cofactors are used for one carbon metabolism?

Answer 10

B2, B6, B9, B12

Question 11

What product acts as a universal methyl donor?

Answer 11

SAMe - acts as the universal methyl donor in over 100 methylation reactions

Question 12

True or False - Polymorphism in the MTHFR C677T gene may lead to hyperhomocystenuria

Answer 12

True

Question 12

Which nutrients are clinically proven to reverse elevated homocysteine levels?

Answer 12

Folate, B12, B6

Question 13

Lack of cofactors required in epigenetics (methylation) may lead to which of the following consequences? Select all that apply:

Answer 13

DNA damage
Genome instability
Switch off or on of gene expression

Question 14

What is the precursor for pyrimidines and purines that allows synthesis of new cells?

Answer 14

Glutamine

Question 15

What are the nutrient cofactors for pyrimidine synthesis?

Answer 15

Glutamine, Serine, Glycine, Niacin Folate

Question 16

What is one carbon cycle mediated by?

Answer 16

The folate cofactor

Question 17

What are the functions of the one carbon cycle?

Answer 17

• Biosynthesis (purines and thymidine)
• Amino acid homeostasis (glycine, serine, methionine)
• Epigenetic maintenance and regulation of methylation
• Redox defence
• Folate/methionine pathways (4 functions)
• Making SAMe

Question 18

If carbon metabolism is dysfunctional what diseases may occur?

Answer 18

• reproductive neural defects
• liver (CVD, hypertension, NAFLD)
• Amino acid and/immune system dysregulation
• Alzheimer’s

Question 19

What is the universal methyl donor of epigenetic processes?

Answer 19

SAMe

Question 20

Purines are progressively oxidized to form which substance to be excreted in urine?

Answer 20

Uric Acid

Question 21

Pyrimidine synthesis begins with which amino acid?

Answer 21

Glutamine