Nutrition & Food Tests Flashcards
Biological molecules
Give us energy.
Carbohydrates
Provide energy.
2 types - Simple and Complex Carbs
Carbohydrates and Fats
Made up of
- Carbon
- Hydrogen
- Oxygen
Cellulose
Found in Plant Cell Walls.
Cannot be digested by humans.
However, as fibre - helps the muscles of intestinal wall to push food through the digestive system.
Cellulose as Fibre
Helps the muscles of intestinal wall to push food through the digestive system.
Cellulose, Starch and Glycogen
Long Chain of Sugars joined together.
Fats/Lipids
A store of energy.
Provide Double the Energy that carbohydrates and proteins do.
Made up of fatty acids and glycerol.
Food
Made up of different biological molecules;
- Which Give us Energy
Contain chemicals we need to:
- Grow and Repair ourselves
- Help our Cells Function
Glucose
Can be used by cells to make energy.
Proteins
Used for the growth and repair of cells
- Used as a source of energy
if carbohydrate and fat reserves are low.
Made up of long chains of amino acids
- which after digestion; are absorbed into the bloodstream
- and brought to cells that reassemble them into proteins needed by the body.
Glycogen
Carbohydrate stored within the liver and skeletal muscle
A Polysaccharide that can be Converted into Glucose when Levels Low.
Reagent
Chemical that indicates the presence of a substance, usually by changing colour.
Proteins contain
- Carbon
- Hydrogen
- Oxygen
- Nitrogen
Starch
Broken down by digestive enzymes into glucose - which can be used by cells to make energy.
Reagents and Food Testing
There are tests which can be used to detect carbohydrates, proteins and lipids.
They involve:
- Adding a reagent to a food sample - changing the colour depending on what biological molecules are present.
- Sometimes it‘s necessary to crush or add water to the food before adding the reagent.
Initial Colour of Benedicts (Reagent)
Blue
Initial Colour of Biuret (Reagent)
Blue
Initial Colour of Ethanol (Reagent)
Colourless
Simple Carbohydrates
Sugars - Glucose and Lactose
Fast Acting Source of Energy.
Complex Carbohydrates
Include - Cellulose, Starch and Glycogen
Source of Slow Releasing.
Complex Carbohydrates Examples
Rice and pasta.
Initial Colour of Iodine (Reagent)
Yellow-brown
Simple Carbohydrates Examples
Biscuits + energy bars.