AP BIOLOGY OUTLINE FOR CELLULAR RESPIRATION: ENERGY TRANFORMATIONS IN CELLS: ANAEROBIC AND AEROBIC RESPIRATION A. Chemical structure and function of ATP 1) Energy transfer 2) Coupled reactions 3) Chemiosmosis B. Pathways of anaerobic respiration 1) Glycolysis 2) Fermentation C. Pathways of aerobic respiration 1) Krebs cycle 2) Electron transport system D. Sites of respiratory enzymes E. Factors affecting the rate of respiration ESSAY QUESTIONS: 1963: Compare the intermediate steps in the fermentation of a molecule of sugar by yeast with respiration in a muscle tissue cell. Include in your answer the role of ATP formed in each of these two processes. 1965: Biologists and biochemists have made outstanding progress within the past quarter century in elucidating principles and structures which govern the activities of living matter. These areas of progress include: A. The structure and code of the DNA molecule B. The use of radioactive isotopes as tracers in biological processes *C. The citric acid cycle and its relationship to mitochondria D. The use of electron microscopy in revealing the structure of the cell Discuss any one of these developments and its impact on biological thought and progress. Your answer should include: a. a brief account of the development b. the names of the most prominent investigators involved c. the nature of its impact on biology 1967: When a cell is metabolizing in the absence of oxygen and it is then exposed to an environment containing oxygen, a series of oxidation-reduction reactions is initiated which enables the cell to increase its activities. a. Outline the oxidation-reduction reactions that are initiated under these conditions and indicate the point at which molecular oxygen interacts with the oxidative system. b. Explain how the cell derives additional energy by switching from non-oxidative to oxidative metabolism. 1977: Explain how the molecular reactions of cellular respiration transform the chemical bond energy of Krebs cycle substrates into the more readily available bond energy of ATP. Include in your discussion the structure of the mitochondrion and show how it is important to the reactions of the Krebs cycle and the electron transport chain. 1982: Describe the similarities and differences between the biochemical pathways of aerobic respiration and photosynthesis in eukaryotic cells. Include in your discussion the major reactions, the end products, and energy transfers. 1989: Explain what occurs during the Krebs (citric acid) cycle and electron transport by describing the following: a. The location of the Krebs cycle and electron transport chain in the mitochondria. b. The cyclic nature of the reactions in the Krebs cycle. c. The production of ATP and reduced coenzymes during the cycle. d. The chemiosmotic production of ATP during electron transport. 1990: The results below are measurements of cumulative oxygen consumption by germinating and dry seeds. Gas volume measurements were corrected for changes in temperature and pressure. Cumulative Oxygen Consumed (mL) ____________________________________________ Time (minutes) 0 10 20 30 40 ____________________________________________ 22o C Germinating Seeds 0.0 8.8 16.0 23.7 32.0 Dry Seeds 0.0 0.2 0.1 0.0 0.1 ____________________________________________ 10o C Germinating Seeds 0.0 2.9 6.2 9.4 12.5 Dry Seeds 0.0 0.0 0.2 0.1 0.2 ____________________________________________ a. Using the graph paper provided, plot the results for the germinating seeds at 22o C and 0o C. b. Calculate the rate of oxygen consumption for the germinating seeds at 22o C, using the time interval between 10 and 20 minutes. c. Account for the differences in oxygen consumption observed between: 1) germinating seeds at 22o C and at 10o C; 2) germinating seeds and dry seeds. d. Describe the essential features of an experimental apparatus that could be used to measure oxygen consumption by a small organism. Explain why each of these features is necessary. 1993: Membranes are important structural features of cells. (a) Describe how membrane structure is related to the transport of materials across a membrane. (b) Describe the role of membranes in the synthesis of ATP in either cellular respiration or photosynthesis. 1995: Energy transfer occurs in all cellular activities. For 3 of the following 5 processes involving energy transfer, explain how each functions in the cell and give an example. Explain how ATP is involved in each example you choose. Cellular movement Active transport Synthesis of molecules Chemiosmosis Fermentation