Photosynthesis II Flashcards
How does light play a role in photosynthesis?
- When chlorophylls absorb light, electrons get hella excited and are transferred to other electron receptors in the chloroplast membrane
- Oxidation from water produces oxygen gas along w/ more electrons and some protons
What happens when water is oxidized?
-It breaks into electron and proton pieces
What is the purpose of the Photosynthesis II lab?
-Measure the rate at which water is oxidized during photosynthesis when we vary the amount of chloroplasts in the reaction
What is the Independent variable?
-Amount of chloroplasts added to the reaction mixture (0mL, 0.1mL, 0.2mL, 0.4mL)
What is the Dependent variable?
-Rate of water oxidation/ Rate of the DPIP reaction (same thing)
What does it mean when DPIP turns clear?
-It is reduced
What 2 mini experiments were present in the photosynthesis II lab?
- The first one was to measure absorption with the varying amounts of chloroplasts added over a period of 10mins at a wavelength of 600nm
- The second one was to determine how light plays a role in absorbance by varying the amount of energy exposed to the test tube (no light no heat, heat no light etc)
What is the relationship between the rate of water oxidation and mL of chloroplasts?
-Its directly proportional= indication that chloroplasts are necessary for photosynthesis
What does the mini-experiment with varying the amounts of energy indicate?
-LIGHT powers photosynthesis, light does the heavy lifting vs. Heat
What does the Photosystems indicate?
- Water is the source of electrons and they FLOW through PII and PI respectively via electron acceptors
- The final electron acceptor is NADP+ and then reduced to NADPH= has high energy to produce glucose
What role does DPIP play in Photosynthesis II experiment?
- It’s a dye that allows the human eye to see when the water is being oxidized
- When it loses its blue color, water is being oxidized
