Water Soluble Vitamins

Question 1

Vitamin B1(Thiamine)

Answer 1

-required for glucose, amino acid, lipid metabolism and DNA and RNA synthesis
-acts as a base to form salts with acids
-unstable in alkaline solutions, when exposed to UV light and heat
-Sulfite food preservatives attack B1 at methylene bridge in structure
-excess is not stored in the body, it is metabolized and excreted by urine

Question 2

Maillard reaction

Answer 2

-is the browning of food when cooked and the associated flavour
-reaction is between reducing sugars and the nitrogen of amino acids
-is a non-enzymatic reaction that occurs in alkaline conditions
-adding baking soda to the food can speed up the process

Question 3

Vitamin B2 (Riboflavin)

Answer 3

-found in both animal and plant based foods
-flavoenzymes catalyst electron transport chain reactions that transfer electrons from electron donors to electron acceptors via redox reaction

Question 4

Vitamin B3 (Niacin)

Answer 4

-all tissues in the body convert niacin to the coenzyme NAD
-more than 400 enzymes require NAD to catalyze reactions in the body

Question 5

Vitamin B5 (Pantothenic acid)

Answer 5

-required to synthesize coenzyme A, which is essential for fatty acid metabolism, synthesis and metabolism of proteins carbs and fats
-effective against acne after 12 weeks

Question 6

Vitamin B6 (Pyridoxine)

Answer 6

-pyridoxine hydrochloride is converted to the active form PLP which is a cofactor for enzymatic activities such as synthesis of amino acids
-in the active form PLP is a coenzyme for enzyme reactions in amino acids, glucose and lipid metabolism
-does not decompose during cooking

Question 7

Vitamin B7 (Biotin)

Answer 7

-involved in metabolic processes, utilization of fats, carbs and amino acids
-marketed to improve health of skin, hair and nails
-deficiency is very rare, only in genetic mutations, alcohol abuse and overconsumption of raw egg whites
-taking it can lead to abnormal lab results: Graves’ disease and low troponin levels which detects heart attacks in people with chest pain

Question 8

Vitamin B9 (Folate)

Answer 8

-naturally occurring in food, dietary supplements and fortified foods including folic acid
-have additional glutamate residues, making them polyglutamates
-folic acid is a fully oxidized monoglutamate

Question 9

Vitamin B12

Answer 9

-air stable solid cofactor for DNA synthesis, metabolism, maturation of red blood cells in bone marrow, synthesis of myelin for normal function in nervous system
-versatility is due to central cobalt ion being able to take part in both one-electron and two-electron reductive processes
-strong affinity absorbs cyanide poisoning
-critical in regenerating folate and methionine cycles
-industrial production is performed by fermentation of microorganisms

Question 10

Vitamin C (Ascorbic acid)

Answer 10

-plays a role in physiological systems such as immune, cardiovascular, neurological and endocrine
-humans are unable to synthesize vitamin C endogenously and must get it from diet
-bioavailability is high but easy destroyed by heat, oxygen and high pH
-excess cannot be stored, it is metabolized and excreted
-transported to mitochondria where free radicals are produced as a byproduct of metabolism
-boils soft foods can leach vitamin C how when boiling hard vegetables they retain more