biological molecules

Question 1

what are the chemical elements that make up carbohydrates

Answer 1

carbon, oxygen and hydrogen

Question 2

uses of carbohydrates

Answer 2

short term energy and respiration

Question 3

chemical elements in protein

Answer 3

carbon, oxygen, hydrogen and nitrogen

Question 4

uses of protein in humans

Answer 4

immune system and muscle development

Question 5

chemical elements in lipids

Answer 5

carbon, oxygen and hydrogen

Question 6

uses of lipids

Answer 6

energy storage
thermal insulation
part of cell membranes

Question 7

chemical elements in nucleic acid

Answer 7

carbon, hydrogen, oxygen, nitrogen and phosphorus

Question 8

uses nucleic acid

Answer 8

genetic makeup

Question 9

solution used to test for glucose

Answer 9

benedicts solution

Question 10

describe the test for glucose

Answer 10

• add Benedicts solution to a sample of food
• place in a water bath for 5 mins
• if glucose is present it will turn from blue to brick red

Question 11

solution used to test for starch

Answer 11

iodine

Question 12

describe the test for starch

Answer 12

• add a few drops of iodine solution to food sample on a spotting tile
• if starch is present it will change from orange to blue/black

Question 13

solution used to test for protein

Answer 13

biuret

Question 14

describe the test for protein

Answer 14

• add 2cm water to food sample and shake
• add biuret solution until it turns pale blue
• if the mixture turns mauve then protein is present

Question 15

describe the test for lipids

Answer 15

• place food sample in a test tube
• add 2cm of ethanol
• and 2cm of water and shake
• if mixture is milky then lipids are present