lab 6 - photosynthesis

Question 1

what is photosynthesis

Answer 1

process by which green plants, algae, and certain bacteria convert light energy and CO2 into organic molecules

Question 2

what is the equation for photosynthesis

Answer 2

6CO2 + 12 water –> 1 glucose + 6O2 + 6 water

Question 3

what happens in the light dependent reactions

Answer 3

energy of sunlight is trapped and converted to ATP and NADPH by the combined activities of ETC and chemiosmosis

products are used to drive the calvin cycle

Question 4

what happens in the light independent reactions (calvin cycle)

Answer 4

CO2 is reduced to carb
don’t directly require light but are dependent on the products from the light dependent reactions

Question 5

what is the hill reaction

Answer 5

reduction of any electron acceptor (A) by electrons and protons from water, with the production of oxygen when chloroplasts are exposed to light

water + A –> A H2 + 1/2 O2

Question 6

what does the hill reaction mean

Answer 6

isolated chloroplasts produce oxygen when they are exposed to light and provided with an electron acceptor even if no CO2 is present

Question 7

what is DCPIP

Answer 7

artificial electron acceptor used to measure the progress of the hill reaction

stronger oxidising agent than NADP+

Question 8

what do the colours of DCPIP mean

Answer 8

colourless = reduced
blue = oxidised

less colour = hill reaction has progressed further

Question 9

what is DCMU

Answer 9

chemical used in herbicides

sued to investigate the effects of photosynthesis inhibitor concentration on the hill reaction

Question 10

what were the results of the experiment containing the inhibitor

Answer 10

higher dilution of inhibitor = more reduction of DCPIP = less colour = lower absorbance reading

more inhibitor = less reduction of DCPIP = more colour = higher absorbance reading