Topic 3 Food And Energy Flashcards
What do carbohydrates do?
Provide energy
What are the two types of carbohydrates?
Simple and complex
What are simple carbohydrates?
Made up of glucose and lactose, fast acting source of energy found in biscuits and energy bars
What are complex carbohydrates?
Made up from starch, cellulose and glycogen and are a slow release of energy found in rice or pasta
Cellulose
Found in plant cell walls, cant be digested, however helps muscles of intestinal wall push food through digestive system
Starch
Broken down by digestive enzymes into glucose, used to make energy
Glycogen
Carbohydrate store, can be converted to glucose
What are lipids?
Fats. They are a store of energy which provide double the energy that carbohydrates and proteins do, are made up of fatty acids and glycerol and are found in cheese, butter or oils
What are proteins?
Made up from long chains of amino acids which repair and grow cells. They are found in fish or eggs
How do all practicals begin in food and energy practicals?
Crushing food sample with pestle and mortar and adding some water to make a solution. After placing the solution in to a test tube the test is ready to be carried out
How to test for sugar
Adds Benedict’s reagent to the food and boil in a water bath. The colour change from blue to green to brick red precipitate will occur
How to test for starch
Add food to a spotting tile then add iodine reagent. The colour change from yellow-brown to blue-black will occur
How to test for protein
Add Biruet’s reagent to the food. The colour change from blue to lilac will occur
What is Biruet’s solution made from?
sodium hydroxide and copper sulfate
How to test for lipids
Add ethanol to the food to dissolve the fat then add water (this is the emulsion test). The colour change from colourless to white emulsion will occur
