P380: Carbohydrates
Energy is stored in molecular bonds of compounds in foods
Carbohydrates = 4 kcal / g
Carbohydrates are a major source of energy for primates and humans. ("our sweet tooth" relates to this) and there are different kinds of carbos:
Link to details about carbohydrates from a U. Penn Nutrition Calls
All contain Carbon rings -- basic multiples
Simple carbohydrates = SUGARS
- monosaccharides (1 carbon ring)
- glucose, fructose, galactose
- rapidly absorbed into bloodstream from small intestine
- di-sacharides (2 carbon units)
- sucrose = glucose + fructose
- lactose = glucose + galactose
- broken down into mono-sacharides by enzymes in small intestine (e.g. lactase)
Complex Carbohydrates = Poly-Saccharides (many carbon units)
- Non-structural Carbos = Starches
- starches = glucose polymers (complex strings of same carbon rings)
- cooking helps to break down starch grains... highly digestible
- AMYLASE = enzyme in saliva begins starch degradation
- Structural Carbos = "Fiber"
- cellulose = "Steel beams of cell wall" glucose polymer with beta bonds, not water-soluble, in fibrils = indigestible by enzymes
- hemicellulose = "cement in cell walls" partly digestible sugar polymers
- pectin = water soluble & readily fermented (alpha bonds polymers)
