University:
Eastern Kentucky University
Course:
BIO 100 | Introductory Biology
Academic year:

2020
Views:

382

Pages:

1
Author:

Karson Orr

LAB 7: Photosynthesis; Lab Notebook Questions 1. What was the purpose of DPIP in this experiment? The purpose of DPIP in this experiment is because it is an electron acceptor and stands in place of ATP and we are allowed to determine the rate of photosynthesis. 2. What molecule found in the chloroplasts does DPIP replace in this experiment? The molecule found in chloroplasts that DPIP substitutes/replace for is NADP molecules. 3. What is the source of the electrons that reduced the DPIP? The source of the electrons that reduced the DPIP is the electrons that come from the photolysis of water. The electrons also reduce the DPIP that comes from chlorophyll after light energy that has entered. 4. What was measured with the spectrophotometer in this experiment? The spectrophotometer measured the percentage of light transmitted through the cuvette due to DPIP reduction. 5. What purpose did the beaker of water serve? What may have happened if you accidentally left it out? The beaker of water served as a heat sink for the experiment. If left out, the samples in our cuvettes may have been exposed to heat as well as light. 6. What results would you have expected if the light source used only shone green light? The expected was that there was to be no change with only shone green light. 7. What reasons can you give for the difference in the percent transmittance between the live chloroplasts that were incubated in the light and those that were kept in the dark? In a dark cuvette there would be no energy because there will be no flow of electrons and no photolysis of water. As well as there will be no flow of electrons. Within the light cuvette there is light energy which allows this process of photosynthesis to occur.