4. Biological molecules Flashcards
chemical elements that make up:
carbohydrates, fats and proteins
Carbohydrates, fats- CHO
Protein- C,H,O,N,S
large molecules are made from smaller molecules- carbohydrates, protein, fats and oil
starch, glycogen and cellulose from glucose
proteins from amino acids
fats and oils from fatty acids and glycerol
food test- starch, glucose, protein, vitamin C, fats and oils
iodine solution test for starch- drops of it to food, yellow-brown to blue-black
Benedict’s solution test for reducing sugars- in test tube in water bath at 80 for 5 minutes. blue to red
biuret test for proteins- drops of it to food, blue to purple
ethanol emulsion test for fats and oils- put ethanol in food so it dissolves, put it in water in test tube. colourless to cloudy emulsion
DCPIP test for vitamin C- 1cm of dcpip in small amount of food, disappears- blue to colourless
structure of a DNA molecule
(a) two strands coiled together to form a double helix
(b) each strand contains chemicals called bases
(c) bonds between pairs of bases hold the strands together
(d) the bases always pair up in the same way: A with T, and C with G