Biological molecules

Question 1

what do molecules in living organisms contain

Answer 1

carbohydrates
proteins
lipids

Question 2

what elements do carbohydrates contain

Answer 2

C, H, O

Question 3

What is a monosaccharide + examples

Answer 3

simple sugar
- glucose and fructose

Question 4

What is a disaccharide + examples

Answer 4

when 2 monosaccharides join together

Question 5

what does maltose contain

Answer 5

two glucose molecules

Question 6

what does sucrose contain

Answer 6

one glucose and one fructose molecule

Question 7

What is a polysaccharide + examples

Answer 7

when lots of monosaccharides join together
- starch, glycogn and cellulose

Question 8

why are polysaccharides used as storage molecules

Answer 8

insoluble

Question 9

what are most fats made up of

Answer 9

triglycerides

Question 10

what do fats contain

Answer 10

one glycerol chemically bonded to 3 fatty acid chains

Question 11

2 types of lipids

Answer 11

fats and oils

Question 12

what are proteins made up from

Answer 12

long chains of amino acids

Question 13

who many amino acids are they

Answer 13

20

Question 14

examples of proteins

Answer 14

enzymes
haemoglobin

Question 15

what determines a proteins function

Answer 15

its shape

Question 16

how do enzymes work

Answer 16

• they have a specifically shaped active site
• for a specific substrate
• if shape of active site does not fit the reaction does not take place

Question 17

test for glucose

Answer 17

• add Benedicts solution
• heat in boiling water bath for 5mins
• take test tube and observe color
• positive test= blue to brick red

Question 18

test for starch

Answer 18

• add drops of iodine solution
• positive test= orange to blue black

Question 19

test for protein

Answer 19

• add drops of bieuret solution
• positive test= blue to lilac

Question 20

test for lipids

Answer 20

• mix 4cm3 of ethanol and shake
• strain ethanol solution into other test tube
• add the ethanol solution to equal volume of cold distilled water
• positive test= cloudy emulsion forming

Question 21

safety test for protein test

Answer 21

• wear goggles because biuret solution contains copper (II) sulfate
• biuret is corrosionve

Question 22

what are enzymes

Answer 22

biological catalyst to speed up the rate of reaction without being changed or used up

Question 23

enzyme-substrate complex

Answer 23

when substrate moves into the enzymes active site

Question 24

what is an enzymes optimum temperature in human body

Answer 24

37

Question 25

denaturation

Answer 25

heating enzymes to high temperatures will break the bonds that hold the enzyme together at it will lose its shape

Question 26

what happens when raising the temperature of the enzymes

Answer 26

• enzymes gain more kinetic energy so the molecules move faster and the number of collisions with the substrate molecules increases
• leads to faster rate of reaction

Question 27

why do enzymes at low temperatures work slowly

Answer 27

lack of kinetic energy

Question 28

what is the optimum pH for most enzymes

Answer 28

7

Question 29

what is the pH of enzymes in the stomach

Answer 29

2

Question 30

pH of enzymes in the duodenum

Answer 30

9

Question 31

what happens if pH is too high or low

Answer 31

the bonds that hold the amino acid chain together can be disrupted/destroyed
- changed the shape of active site