ASSIGNMENT 2
In the text box, number your answers and use standard font size (12 or 14 pt). You do not need to re-write the questions. Point values shown in parentheses. Please check your grammar and spelling.
Unit 2 Assignment Questions:
1. (2) What is the source of electrons in the mitochondrial electron transport chain? And where do the electrons end up once they pass through the chain?
2. (2) Molecules called uncouplers (such as dinitrophenol) poke holes in the inner mitochondrial membrane. What effect would this have on aerobic respiration?
3. (2) Define “exogenous” and “endogenous” electron acceptors.
4. (4) The conversion of pyruvate to lactate in lactic acid fermentation and the conversion of pyruvate to ethanol in alcoholic fermentation does not produce ATP – and in fact, both ethanol and lactate are waste products. So why do cells run fermentation reactions?
5. (2) Why are plants green?
6. (2) What is the source of the electrons in the electron transport chain in the chloroplast? And where do the electrons end up once they pass through the chain?
7. (4) In hot and dry climates, plants face extra challenges… when their stomata are open, plants can do the gas exchange they need for photosynthesis, but they also lose water. However, closing stomata to prevent water loss causes the internal levels of CO2 to fall… and this presents a problem because when plants run out of CO2, the enzyme RuBisCO will bind oxygen instead in a process called photorespiration. Define photorespiration and explain the two main strategies plants use to prevent it (they are called C4 plants and CAM plants).
8. (2) Some birth defects and some cancers are the result of aneuploidy. What is aneuploidy and how does it relate to the cell cycle? Use your own language and cite your reference.
