Upgrade to remove ads
BIO LAB PRACTICAL 2
Terms in this set (19)
Which of the following best represents the dependent variable in the experiment that used the DPIP dye?
The rate of water oxidation.
Which of the following best represents the independent variable in the experiment that used the DPIP dye?
The volume of chloroplasts added to the experimental tube.
When oxidized DPIP is mixed with illuminated chloroplasts what happens?
DPIP gains electrons and loses its blue color.
Which of the following best explains the purpose of using a buffer in the dye reduction lab?
To prevent changes in pH in the chloroplast preparation
What do chloroplasts and sodium bisulfite hold in common?
Sodium bisulfite and chloroplasts cause DPIP that is initially blue in solution to become colorless. Sodium bisulfite and chloroplasts reduce DPIP.
In the reaction you studied in the dye reduction laboratory, where did the electrons that changed the DPIP come from?
In the oxidation of water lab that utilized the blue dye DPIP, which of the following represents a measured (dependent) variable?
Change in absorbance over time. Measured the loss of blue color (i.e., the reduction of DPIP)
Which of the following wavelength settings is best for having a Spec 20 detect the absorbance of light by a substance that is blue in solution?
600 - red region
Which of the following do chloroplasts and sodium bisulfite hold in common?
Sodium bisulfite and chloroplasts may cause DPIP that is initially blue in solution to become colorless.
Which of the following exercises that you performed in lab best shows that chloroplasts play a crucial role in the color change of DPIP?
Comparing the absorbance changes in separate tubes in which increasing amounts of chloroplasts were added. Showing that increasing amounts of chloroplasts increase the rate of DPIP reduction provides evidence that chloroplasts are the active ingredient in this experiment.
What was the purpose of using a buffer for the isolation and function assessment of chloroplasts?
To eliminate pH as a variable in the experiment.
The reduction of DPIP by chloroplasts was coupled to which reaction below?
The oxidation of water. When water is oxidized in photosynthesis it looses electrons. Those electrons are available to reduce DPIP.
Which of the following are capable of reducing DPIPox
Sodium bisulfite. Illuminated chloroplasts.
Which of the following is/are true of the absorption spectrum of chlorophyll b as studied in lab?
Chlorophyll b had an absorption peak the red region of the visible spectrum. Chlorophyll b had an absorption peak the blue region of the visible spectrum.
The absorption spectrum of carotenes as determined in lab sometimes showed an absorption peak in the red region of the spectrum. However, the absorption spectrum of carotenes shown in the textbook did not show such a peak. What caused this difference?
The carotenes extracted in our lab were contaminated with chlorophyll; the carotenes used in the textbook were not contaminated with chlorophyll.
Which of the following is done to determine the absorption spectrum of a substance?
Measure its absorbance over a range of different wavelengths of light.
Which of the following is/are true of the solubilities of the pigments studied in lab?
Carotene is more soluble in ethanol than in petroleum ether.
In the oxygen production lab, how was PFR varied?
The PFR was varied by adjusting the distance between the light source and the tube containing Chlorella.
In the oxygen production lab, what compensation was made for the heat generated by the lamps?
A tank of water was placed in the light path to absorb heat.
OTHER SETS BY THIS CREATOR
BIO EXAM THREE ANSWERS
BIO EXAM TWO ANSWERS
BIO EXAM ONE ANSWERS
Photosynthesis #3 (Oxygen production)