Photosynthesis Lab P3

Question 1

When Photosystem II absorbs light energy it is able to ___

Answer 1

remove electrons from the water

Question 2

what are the electrons free from the water energized by and used for

Answer 2

energized by light
used to reduce CO2 to produce energy-rich molecules like glucose

Question 3

ATP is used in the ___ cycle to help make ___

Answer 3

Calvin-Benson
glucose

Question 4

Oxygen is vital in ____

Answer 4

cellular respiration

Question 5

What does oxygen allow for?

Answer 5

many organisms, plants included, to fully extract the potential energy of glucose

Question 6

What is the purpose of this lab

Answer 6

the effect of light quantity on the rate of oxygen production by an alga called Chlorella

Question 7

Independent variable

Answer 7

light quanitity

Question 8

dependent variable

Answer 8

rate at which Chlorella produces oxygen

Question 9

How is the rate of oxygen production measured?

Answer 9

with a dive that generates tiny flashes of light detected by a photodiode; the rate at which the flashed are produced is proportional to dissolved oxygen concentration

Question 10

What is the relationship between PFR and oxygen production rate in chlorella?

Answer 10

direct - higher PFR, higher O2

Question 11

If the “no light control” rate was negative, what was happening to oxygen in the dark Chlorella tube? For what do plants use oxygen?

Answer 11

The Chlorella were carrying out aerobic respiration, that is, they were using oxygen to oxidize sugars that they had made previously.

Question 12

DCMU is an herbicide; it blocks the transfer of electrons out of photosystem II. How would DCMU affect the production of oxygen in plants? How might DCMU negatively affect the production of glucose in a plant?

Answer 12

reduced oxygen evolution and impairs glucose synthesis