Apparatus & Techniques

Question 1

spectroscope

Answer 1

measures the properties of different wavelengths of light

Question 2

calirometer

Answer 2

measures the heat produced in a chemical reaction

Question 3

simple fermenter

Answer 3

used to grow bacteria and fungi in large amounts

Question 4

fermenter: steam inlet

Answer 4

sterilises and prevents contamination

Question 5

fermenter: nutrient inlet

Answer 5

provides nutrients for the bacteria to grow

Question 6

fermenter: water jacket

Answer 6

keeps temperature at optimum

Question 7

fermenter: air inlet

Answer 7

lets in oxygen for aerobic respiration

Question 8

fermenter: filter on air inlet

Answer 8

prevents microorganisms contaminating

Question 9

fermenter: stirring paddles

Answer 9

mixes microorganisms with nutrients

Question 10

fermenter: pH probe

Answer 10

checks pH is at optimum

Question 11

fermenter: acid & alkali intake valve

Answer 11

changes pH if required

Question 12

chromatography

Answer 12

used to separate photosynthetic pigments

Question 13

chromatography process

Answer 13

• grind leaf with sand and solvent to break open cells
• filter solution
• drop a spot of solution onto chromatography paper
• dry with hairdryer
• repeat spotting & drying multiple times to create strong concentration of pigment
• place chromatography paper in a boiling tube with chromatography solvent (not touching the spot)

Question 14

Rf value

Answer 14

distance moved by pigment/distance moved by solvent

Question 15

gel electrophoresis

Answer 15

separates macromolecules eg. DNA fragments

Question 16

PCR process

Answer 16

• DNA heated to 92-98 (break strands open)
• Cooled to 50-65 (complementary primers bind to target DNA sequences)
• heated to 70-80 (heat tolerant polymerase replicates region)
• repeat multiple times

Question 17

how does a respirometer function?

Answer 17

• oxygen usage causes coloured liquid to move, caused by the reduction in volume of oxygen increasing pressure
• tubes contain alkali to absorb carbon dioxide
• glass beads used as a control