the chemicals of life Flashcards
carbohydrates are made of
carbon, hydrogen, oxygen
monomers of carbohydrate
monosaccharide/glucose
larger (insoluble) carbohydrates
starch, glycogen, cellulose
smaller (soluble) carbohydrates
- complex sugars such as maltose, sucrose
- simple sugars such as glucose, fructose
fats are made of
carbon, hydrogen, oxygen
monomers of fats
three fatty acid molecules attached to one glycerol
proteins are made of
carbon, hydrogen, oxygen, nitrogen (sometimes sulphur or phosphorus)
monomers of proteins
amino acids are linked together to form polypeptides which link together to form proteins
how to test for carbohydrates (starch)
- put a few drops of iodine solution on sample to be tested
- positive = blue-black
- negative = remains brown
how to test for carbohydrates (reducing sugars)
- make a food solution + add equal amount benedict’s solution + heat test tube in a water bath
- positive = red/orange/yellow/green
- negative = blue
how to test for fat
- mix ethanol with the food solution + add this to a test tube of water
- positive = cloudy white emulsion
- negative = water remains clear
how to test for protein
- add biuret reagent to the food solution
- positive = lilac
- negative = blue
how to test for vitamin c
- add solution drop by drop to DCPIP
- positive = colourless
- negative = remains blue
what is DNA
a long twisted double-stranded (double helix) molecule held together by pairs of chemical units called bases (A-T, C-G)
