B: Nutrients

• Needed in relatively large amounts ( >0.005% of body mass) • proteins, carbohydrates, fats • minerals: Na, Mg, K, Ca, P, S, Cl

• Needed in less than <0.005% of body mass • measured in mg (10-3) or Mg (10-6) • Vitamins • Trace minerals –> enzyme function • Fe, Cu, F, Zn, I, Se, Mn, Co, B

• Conjugation –> electron delocalization –> colored • large nonpolar section –> fat soluble

• soluble in water –> number of hydroxyl groups which will hydrogen bond to water molecules • not conjugated –> not colored

• not colored • fat soluble

• Vitamin C: water soluble –> excreted from the body, needs to be replenished on a regular basis • Vitamin A and D: dissolved in fat tissue –> can build up to dangerous levets, intake has to be controlled

• Vitamin supplements (tablets) / injections • fortified fruit and vegetables • genetically modified food

• most vitamins are sensitive to heat • eg Vitamin C does not get denature –> undergoes an oxidation reaction to form initially dehydroascorbic acid