B3 Flashcards
What are the three major nutrients?
Carbohydrates, Lipids, Proteins
what is carbohydrates major function?
Source of energy, glucose is the main respiratory substrate
what is proteins major function?
Growth and repair
what is lipids major function?
Energy, make up part of cell membranes so essential for normal growth
what is bile?
produced in the liver it breaks down fats and lipids in the stomach.
what are the stages food passes?
- mouth
- oesophagus
- stomach
- large+small intestine
- bladder
amylase description
the enzymes the break down starch to sugar.
Enzyme description
breaks nutrients down, affected by pH level, and tempriture
describe a catalyst
- speeds the reaction
- enzymes are sometimes described as biological catalysts
what is the order for body systems?
cells tissue organs organ system organism
how can an enzyme become denatured?
Higher temperatures disrupt the shape of the active site, which will reduce its activity, or prevent it from working.
how do you test for sugars?
-add Benedicts solution to the food+water
-heat in a water bath
-the Benedicts solution will change colour when heated
green, yellow, orange, red or brown - depending on how much glucose is present
testing for starch
Use iodine on an exposed area of food
Foods containing starch will turn a blue-black colour.
Testing for proteins
The biuret test is used to detect proteins.
Add 1 cm3 of biuret solution A to the food solution.
Mix the liquids.
Add 1 cm3 of biuret solution B and shake.
-purple if present or a seperated purple ring
Test for fats
The Sudan III test
-add equal amounts of food + water
- shake after dropping some sudan III solution
it will turn red is present
