4.1 Molecules Flashcards
ur mama
What do carbohydrates contain in terms of chemical elements?
Carbon, hydrogen and oxygen.
What are monosacharrides what does it consist of
-one unit of sugar
- glucose and fructose
What are disaccharides and what does it consist of?
- two monosaccharides bonded
- maltose and sucrose
What are carbohydrates made of?
monosaccharides, disaccharides and polysacchides
What is a polysaccharide? What is an example of it?
It is :
- Many monosaccharides bonded
- e.g : Starch and glycogen
What are proteins made up of?
- smaller units called amino acids
What do proteins contain?
- carbon
- hydrogen
- oxygen
- nitrogen
What do lipids contain?
-carbon
-hydrogen
- oxygen
What are the states of lipds in room temp
-oil if liquid
- fats if solid
Food test: Startch
1) what do i use to determine whether startch is present? Example of food sample to experiment on?
2) What is the procedure?
3) What colour does it change to if its :
(i) +ve
(ii) -ve
1) Iodine e.g with bread
2) Add a few drops
3) (i) blue-black colour
(ii) brown
What are lipids comprised?
Two smaller units:
-glycerol
- fatty acids
Food test: Reducing sugars
1) what do i use to determine whether it is present? Example of food sample to experiment on?
2) What is the prodedure?
3) What colour does it change to if its :
(i) +ve
(ii) -ve
1) BENEDICT’S reagent
2) The mixture is heated in water bath for 2 to 3 minutes.
3) (i) +ve: brick-red precipitate
(ii) -ve: remains blue
Food test: Protein
1) what do i use to determine whether it is present? Example of food sample to experiment on?
2) What is the prodedure?
3) What colour does it change to if its :
(i) +ve
(ii) -ve
1) BIURET reagent
2) Add a few drops
3) (i) +ve: mauve/purple colour
(ii)-ve: remains light blue
Food test: Fats
1) what do i use to determine whether it is present? Example of food sample to experiment on?
2) What is the prodedure?
3) What colour does it change to if its :
(i) +ve
(ii) -ve
1) Use an emulsion test : with ethanol, e.g experiment with butter.
2) Ethanol is added to mixture and this is poured into a test tube with a equal amound of distilled water,
3) (i) +ve: milky-white emulsion
(ii) -ve: no emulsion will form
Food test: Vitamin C
1) what do i use to determine whether it is present? Example of food sample to experiment on?
2) What is the prodedure?
3) What colour does it change to if its :
(i) +ve
(ii) -ve
1) DCIPIP, e.g experiment with orange
2) The more drops you need to add the less concentrated the vitamin c is and vice versa.
3) (i) colourless
(ii) remains dark blue
