2 a. The addition of DNP would allow all ions to pass through the membrane. As a result, the mitochondira would no longer be able to produce ATP. The absence of a proton gradient means ATP synthase cannot function.
2 b. Normally, K+ helps create the proton gradient in membranes by "pushing" protons through ATP synthase. The addition of nigericin would allow only K+ to pass through the membrane, which would result in equilibrium of K+. This would eliminate the help normally provided by K+ to create the proton gradient. ATP synthesis would indirectly become less efficient.
3. The experiment tested the ability of algae to photosynthesize at various wavelengths of light. Englemann had to make sure that algae placed in the test tube with oxygen-dependent bacteria was the sole source of oxygen. He did this by allowing the bacteria to first use up all the oxygen avilable before pairing it with the algae-- guaranteeing that he was measuring the oxygen produced only by photosythesis. A prism seperated the light, each color having a different wavelength. The algae were placed under these different wavelengths of light, and with that Englemann was able to determine the action spectrum of green algae.
