Session 9 - Nutrient Control Gene Expression Flashcards
What are nucleotides made up of?
Phosphate
A nitrogenous base
Deoxyribose sugar
What can be synthesised by de novo pathway?
Purines and pyrimidines
What is the first product in the de-novo pathway of purine synthesis?
5 phospo-a-D-ribosyl 1 pyrophsophae (PRPP) PRPP (1st step)
Which of the following nutrients is NOT required as cofactor in Purine synthesis?
Manganese
What nutrient cofactors are required in Purine synthesis?
Glutamine, Magnesium, Iron, B2, B3, Molybdenum
What is the end product of purine metabolism?
Uric Acid
Faults in purine metabolism (such as deficiency of enzyme HPRT) may lead to which health risks?
Hyperuricemia
Gout
Kidney Stones
What are telomeres?
The non coding sequence at the tail end of a chromosome
How are telomere length preserved?
Exercise
Dietary intake of antioxidants
Optimal folate status - low blood folate is associated with shorter telomeres
What nutrient cofactors are used for one carbon metabolism?
B2, B6, B9, B12
What product acts as a universal methyl donor?
SAMe - acts as the universal methyl donor in over 100 methylation reactions
True or False - Polymorphism in the MTHFR C677T gene may lead to hyperhomocystenuria
True
Which nutrients are clinically proven to reverse elevated homocysteine levels?
Folate, B12, B6
Lack of cofactors required in epigenetics (methylation) may lead to which of the following consequences? Select all that apply:
DNA damage
Genome instability
Switch off or on of gene expression
What is the precursor for pyrimidines and purines that allows synthesis of new cells?
Glutamine
What are the nutrient cofactors for pyrimidine synthesis?
Glutamine, Serine, Glycine, Niacin Folate
What is one carbon cycle mediated by?
The folate cofactor
What are the functions of the one carbon cycle?
- 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
If carbon metabolism is dysfunctional what diseases may occur?
- reproductive neural defects
- liver (CVD, hypertension, NAFLD)
- Amino acid and/immune system dysregulation
- Alzheimer’s
What is the universal methyl donor of epigenetic processes?
SAMe
Purines are progressively oxidized to form which substance to be excreted in urine?
Uric Acid
Pyrimidine synthesis begins with which amino acid?
Glutamine
