biological molecules (topic 4)

Question 1

what chemical elements make carbs

Answer 1

carbon hydrogen and oxygen

Question 2

what chemical elements make proteins

Answer 2

carbon hydrogen oxygen and nitrogen

Question 3

what chemical elements make fats

Answer 3

carbon hydrogen and oxygen

Question 4

what large molecules are made from glucose

Answer 4

starch, glycogen and cellulose

Question 5

what is made from amino acids

Answer 5

proteins

Question 6

what are fats and oil made from

Answer 6

fatty acids and glycerol

Question 7

what tests for starch and colour change present

Answer 7

iodine solution
negative- organe/brown
positive- blue/black

Question 8

what tests for reducing sugars and colour change present

Answer 8

benedicts solution (must keep in warm water bath)
no sugar->sugar spectrum:
-blue
-green
-yellow
-orange
-red

Question 9

what tests for fat and oils and colour change present

Answer 9

ethanol emulsion test (must add water as well and mix)
negative- no change
positive- cloudy/milky white

Question 10

what tests for protein and colour change present

Answer 10

biuret test
negative-blue
positive-violet

Question 11

what tests for vitamin c and colour change present

Answer 11

DCPIP test
positive- blue-colourless
negative- no colour change stays blue

Question 12

structure of a dna molecule

Answer 12

two strands coiled together to form a double helix each strand contains chemicals called bases bonds between pairs of bases hold the strands together the bases always pair up in the same way: A - T, and C - G