Carbohydrate, fat and protein Flashcards
Carbs
- composition
- Carbon
- Hydrogen
- Oxygen
Carbs
- general formula
(CH2O)n
Types of carbs
- Monosaccharides
- Oligosaccharides
- Polysaccharides
Monosaccharides
Basic unit of carbohydrates
Oligosaccharides
2 - 10 sugars bonded chemically
(disaccharides most common) - sucrose
Polysaccharides
3 to thousands of sugars linked together
Monosaccharides
- Types
- Glucose
- Fructose
- Galactose
Glucose
Blood sugar
Fructose
fruit sugar (sweet tasting sugar)
Galactose
Does not exist free in nature
-High Glycaemic index
Disaccharides
- Lactose = Glucose + Galactose
- Sucrose = Glucose + Fructose
- Maltose = Glucose + Glucose
Lactose
- Least sweet sugar
- Milk
Sucrose
- Most common sugar
- Honey, cane sugar
- maple syrup
Maltose
Beer, breakfast cereal
Plant polysaccharides
- Starch
- Fibre
Starch
- 80-90% of all polysaccharides we eat
- Lower glycaemic index
- Most important source of carbs (AKA complex carbs) - Amylose, amylopectin
- Found in seeds, corn, grains of cereal etc.
Fibre
- Non-starch, structural polysaccharide
- Found in legumes, some fruits, juices and certain veg
Role of CHO
- Energy source
- Catabolism of blood glucose and glycogen from liver and muscles fuels muscle contraction
- Fuel for the central nervous system
Lipids
- Structure
Same structural components as carbohydrates
Hydrogen to oxygen ratio
High
Types of Lipids
- Simple
- Compound
- Derived
Simple lipids
- Most common
Triacylglycerols
- Made up of 3 fatty acids and a glycerol
- Main form of fat in adipocytes
- One of the most important forms of dietary fat
Fat energy density
Fat is energy-dense, get more energy from 1g of fat than 1g of carbs
Types of fatty acid
- Saturated
- Unsaturated