Nutrients Flashcards
Structure of Carbohydrates & range in size and complexity
Contains carbon, hydrogen and oxygen atoms.
Largest to smallest of size and complexity of CHOs
- Polysaccharides (eg. cellulose)
- Oligosaccharides (eg. maltodextrin)
- Disaccharides (eg. sucrose and lactose)
- Monosaccharides ( eg. glucose and fructose)
Functions of Carbohydrates
Main human energy source (45-65% total food energy intake)
Helps control blood glucose and insulin metabolism
Energy storage
Participates in cholesterol and triglyceride metabolism
How do Carbohydrates storage energy
Extra glucose in the bloodstream is stored as glycogen in the liver and muscle tissue until needed for energy use.
Excess glucose that can’t be stored as glycogen is turned into fat through LIPOGENESIS.
Simple Carbohydrates are what, where are they found & examples
- Mono and disaccharides (sugars)
- Easily utilised for energy - causes a rapid rise in blood sugar
- eg. fructose, lactose, sucrose and glucose
- Found in lollies, fruit juice, sugar and honey
Complex Carbohydrates are what, where are they found & examples
Oligo and polysaccharides
Takes long to digest and has slow effects on blood sugar
Eg. cellulose and amylose
Found in apples, lentils, brown rice, whole grains
Starches are what and found where?
Complex CHOs with a lot of glucose
Found in potatoes, pasta and wheat
Fibre are what and found where?
Nondigestible complex CHO with a lot of cellulose and pectin.
- Insoluble: good for healthy bacteria growth in colon and helps with defecation.
- Found in the brain, seeds and vegetables
- Soluble: helps decrease blood cholesterol
- Found in oats, broccoli and dried beans.
Protein structure
Are linear polymers built of monomer units called amino acids
Function - depends on its individual structure, determined by the sequence of 20 possible amino acids.
Contains - C, H, O, N and often S, P.
Protein Functions
Provides 15-25% total food energy intake.
Catalysts (enzymes)
Transports and stores other molecules, like oxygen (carrier & channel proteins)
Generates movement (actin & myosin In muscle)
Transmits nerve impulses (Na+ channel)
Controls growth and differentiation (hormones)
Lipids structure
Are a group of compounds (usually insoluble in water)
- Foods sources are edible oils and fats
Contains C, H and small amounts of oxygen.
Made of glycerol and fatty acids.
- Can be saturated, unsaturated or trans fat.
- High and low-density lipids
Triacylglycerols make up 95% of dietary lipids
- Made up of glycerol and fatty acids
Functions of Lipids
Serves as energy storage (fats/oils) Constituents of membranes (cholesterol, phospholipids) HOrmones (steroids) Vitamins A, D, E and K (fat-soluble) Oxygen / electron carrier (heme)
Functions of Vitamins
Provides no energy BUT are essential for proper functioning of the body (like minerals).
Required in SMALL amounts (micrograms / milligrams)
Are organic substances with important roles in metabolism like co-enzymes.
List 6 vitamins and what they do
A - Retinol production (eyesight B - 8 different vitamins are needed in energy metabolism C - Protein metabolism D - Required for calcium absorption E - Antioxidant K - Required for blood cotting
Vitamins can be broadly divided into what two classes?
Water-soluble Vitamins
- Not stored in the body. Required more frequently than fat-soluble vitamins.
Fat-soluble vitamins
- Stored in the liver and fatty tissues until required.
- Can be harmful if too much is taken in
4 examples of VITAMIN deficiencies
Blindness - Vitamin A (retinol production)
Anemia - Vitamin B12 )energy production)
Scurvy - Vitamin C (collagen production)
Rickets - Vitamin D (calcium absorption)
