Lab Exam 2: Lab 7 Flashcards
What is chlorella a member of?
A member of phylum Chlorophyta
What category of organism is chlorella?
An aquatic photosynthetic unicellular organism
What is the independent variable?
Light quantity, measured as photon fluence rate (PFR)
What are the units of PFR?
Micromoles of photons per square meter per second
What is the dependent variable?
The rate at which Chlorella produces oxygen
How does the device detect oxygen?
The device generates tiny flashes of light that are detected by a photodiode
What is the relationship between the flashes produced by the device and the oxygen concentration?
The rate at which the flashes are produced is proportional to dissolved oxygen concentration
What is the relationship between PFR and oxygen production rate in Chlorella?
Directly related; As PFR (light) increases so does the production rate of oxygen
If the “no light control” rate was negative, what was happening to oxygen in the dark Chlorella tube? For what do plants use oxygen?
The oxygen rate was negative because since no photosynthesis was occurring, and no oxygen being produced, Chlorella was actually taking oxygen in for cellular respiration
DCMU is an herbicide that blocks the transfer of electrons out of photosystem II. How would DCMU affect the production of oxygen? How might it negatively affect the production of glucose in a plant?
Because electrons are not properly transferred, it would decrease the production of oxygen because water is no longer be oxidized for its electron to replace the electron-deficit chloroplast. As a result, it would negatively affect the production of glucose because photosynthesis will not occur as efficiently and therefore sugar will not be produced which means the plant cannot gain energy.
