Cytochromes a. contain heme prosthetic groups b. function as electron carriers
4. Fe-S Proteins a. also participate in electron transfer b. do not have a heme prosthetic group What is ATP synthase? How does it work? - the proton-motive force of the H+ gradient drives ATP synthase - the rotor spins as H+’s pass through - makes ATP from ADP What is fermentation? Two examples of fermentation from class? - regenerates NAD+ from NADH so that glycolysis can continue - electrons removed from NADH are transferred to pyruvate - ex) lactic acid - ex) alcohol Why is fermentation less efficient than respiration? - glucose is not completely oxidized - Oxygen is more electronegative than NADH - fermentation yields 2 ATP vs 29 ATP per glucose LECTURE 8 - Photosynthesis What is the relationship between aerobic respiration and photosynthesis? - photosynthesis produces oxygen and glucose - respiration produces CO2 and H20 - photosynthesis needs CO2 and H20 while respiration needs oxygen and glucose
- the products of photosynthesis support respiration and the products of respiration support photosynthesis What does Photosystem I produce? - makes NADPH What does Photosystem II produce? - makes ATP and uses electrons from light What does the Calvin Cycle produce? - the light reactions provide ATP and NADPH to the calvin cycle - the calvin cycle produces ADP, Pi and NADP+ and those get sent back to the light reactions Where in the chloroplasts do photosystem I, photosystem II and the calvin cycle take place? - stroma of the chloroplasts What are the structures and functions of chlorophylls and carotenoids? - chlorophylls are the main light-absorbing pigments in plants - carotenoids are accessory pigments that extend the range of wavelengths that may drive photosynthesis How are the different photosystems arranged? - What is the Z-scheme model? - it illustrates how these photosystems interact - proposes that electrons from water are first energized by photosystem II to generate ATP and then energized again by photosystem I to reduce NADP+ to NADPH - When H+ reach the end of the ETC, they are passed to plastocyanin which donates the electron to an oxidized reaction center pigment in Photosystem I - basically it links photosystems I and II What is cyclic electron flow? - it is alternative to the Z-scheme - instead of being donated to NADP+, electrons are returned to PQ and cycle between photosystem I and the ETC, resulting in the production of additional ATP via photophosphorylation
What is the Calvin cycle? Know its three major phases - it is Light independent, but depends on the products of the light-dependent reactions - carbon fixation is the addition of CO2 to an organic molecule (the C in CO2 is reduced) - Steps of Cycle 1. Fixation a.