B4 - Biological molecules Flashcards
what are the chemical elements that make up carbohydrates?
carbon, hydrogen, oxygen
what are the chemical elements that make up fats?
carbon, hydrogen, oxygen
what are the chemical elements that make up proteins?
carbon, hydrogen, oxygen, nitrogen
what are the smaller molecules in starch?
sugar –> glucose
what are the smaller molecules in proteins?
amino acids
what are the smaller molecules in fats and oils?
glycerol and fatty acids
what are the smaller molecules in glycogen?
glucose
what are the smaller molecules in cellulose?
glucose
what is the test for starch?
Iodine. If the sample changes colour from browny-orange to blue-black, starch is present, if the sample stays browny-orange, there’s no starch
what is the test for reducing sugars?
Benedict’s Solution. Add benedict’s solution (blue) to a sample and heat it in a water bath (75C), higher the concentration of reducing sugar, the further the colour change goes.
colour changes:
blue (none) –> green (traceable) –> yellow (low) –> orange (moderate) –> brick red (high)
what is the test for proteins?
Biuret test. If there’s no protein, the solution will stay blue, if there is protein, solution will turn purple.
what is the test for fats and oils?
Ethanol Emulsion Test. Shake test substance with ethanol and pour the solution into water, if there is a layer of milky emulsion on top of the water, there is fat/oil present. If there’s no fat/oil, the test substance will stay colourless.
what are biological molecules?
molecules found in living organisms
what are the 4 reasons biological molecules are needed?
Energy
Growth
Repair
Health
what are the 7 food groups?
carbohydrates
lipids (fats)
protein
water
vitamins
minerals
fibre
