Reference no: EM132836702

BIOL 1304 Human Biology - The University of Texas at El Paso

Lecture title: Energy, Metabolism, and Enzymes: Part I

1. GUIDING QUESTION: Nearly all ecosystems on our planet rely on photosynthesizing organisms (including bacteria, algae, and plants) that harness solar energy. However, hydrothermal vent ecosystems are an important exception in which chemosynthesizing organisms form the energetic foundation. Contrast photosynthesis and chemosynthesis in terms of their basic chemical equations; how are they similar, and how are they different? What types of organisms undergo chemosynthesis? Provide one reason why it is important for scientists to be aware of hydrothermal vent ecosystems as an important exception in this way.

2. Provide the overall summary equation for photosynthesis. Provide the overall summary equation for the form of chemosynthesis discussed during lecture. In what ways are they similar? In what ways are they different?

3. Define energy (E).

4. Energy is ______________, but its effects can be ______________.

5. List six distinct forms of energy. How are these six forms of energy related to the two major categories of "potential E" and "kinetic E"? Why is chemical E considered a form of potential E? Why are mechanical E, electrical E, light (radiant) E, and heat E considered forms of kinetic E?

6. List and discuss the First and Second Laws of Thermodynamics. What is meant by the term "entropy"? Explain why these laws of physics/chemistry are so important to biological studies.

7. During energy transformations, much energy is often "lost" in the form of ____________.

8. What is the difference between an endergonic and an exergonic chemical reaction? Be sure to use biological monomers and polymers in your answer. What does it mean to say that exergonic reactions are coupled with endergonic reactions in biological systems?

9. What does ATP stand for? Be sure you can identify its structural formula (i.e., drawing of its molecular structure). Why is ATP used by cells as an "universal" energy currency?

10. Define the following terms: metabolism, metabolic pathway, enzyme.

11. Which metabolic pathway involves the oxidation of glucose and is performed by human cells and most pathogenic bacteria? Which metabolic pathway involves the reduction of carbon dioxide and is performed by plants and certain bacteria? What is meant by the terms "oxidation" and "reduction"?

Lecture title: Energy, Metabolism, and Enzymes: Part II

12. GUIDING QUESTION: Enzymes are biological catalysts for amazing power. For instance, soil bacteria use enzymes to fix nitrogen in the air into ammonia even in cold weather. (Nitrogen is abundant in the air all around us but is chemically inert and unavailable to plants and animals, which rely on nitrogen-fixing bacteria to chemically transform the nitrogen in air into chemically useable forms.) To achieve the same reaction (nitrogen gas ? ammonia), in human industry, the reactants must be subjected to 500oC (932oF) temperature and a pressure of 300 atmospheres. Look up the molecular structure of gaseous nitrogen (found in air); why is this molecule so difficult to break down chemically? Name at least three types of bacteria that can achieve this amazing feat of transforming gaseous nitrogen in the air into ammonia, a form of nitrogen that ultimately becomes available to plants, and then animals, and humans!

13. Define metabolism (again). Define catabolism and anabolism, and provide an example of each.

14. What is meant by the term "activation energy" and how does this concept relate to enzyme function?

15. Without enzymes, the chemical reactions would occur much more _____________ and ____________.

16. Discuss the following topics related to enzyme function: specificity, substrate, active site, conformation, competitive inhibition, and non-competitive inhibition.

17. Some of the first anti-HIV drugs were ______________ inhibitors that targeted which important HIV enzyme?

18. By controlling the formation of specific enzymes, a cell may exert control over its ______________ in a _______________ manner.

19. What is the relationship between temperature and optimal enzyme function? What is the relationship between pH and optimal enzyme function? How are the effects of temperature and pH on enzyme function similar and different?

20. Almost all enzymes are ____________. What happens to an enzyme when it becomes "denature"? What factors can lead to denaturation (beyond extremes in temperature or pH)?

21. "Pasteurization" was named to honor which important biologist/chemist? Describe the process of Pasteurization.

22. The two major metabolic pathways known as cellular respiration and photosynthesis require that specific enzymes are in very close proximity to their chemical substrates. Discuss two ways in which cells ensure that this occurs.

Lecture title: Photosynthesis

23. GUIDING QUESTION: The most abundant molecule on Earth is an enzyme known as RuBisCo (= ribulose-biphosphate carboxylase oxygenase), which plays a central role in photosynthesis. There may be around 40 million tonnes or Rubisco in the biosphere-about 8 kg (18 lb.) per person on the planet. What crucially important function does this enzyme perform? Specifically: consider the reactants and products of the chemical reaction that Rubisco catalyzes. What would happen if Rubisco suddenly disappeared from the face of the Earth?

24. In what important organelle does photosynthesis take place in eukaryotes? What important cell component is involved in photosynthesis in prokaryotes?

25. What is a photosynthetic pigment, and which pigment is most common in plants?

26. Compare and contrast the overall summary equation for oxygenic and anoxygenic photosynthesis.

27. How is photosynthesis important to cellular respiration, and vice versa? Do plants perform cellular respiration, in addition to photosynthesis?

28. NADP+/NADPH and NAD+/NADH are specialized ______________ that store energy in loosely bound ____________ and ___________ atoms. NADP+/NADPH plays a key role in which major metabolic pathway? NAD+/NADH plays a key role in which major metabolic pathway? Why is there a transformation "back and forth" between NADP+??NADPH and NAD+??NADH?

29. List and discuss the summarize the three different ways in which ATP is generated in cellular respiration and photosynthesis. Which of these three ways forms ATP directly in a single (enzyme-catalyzed) chemical reaction? Which of these three ways forms ATP indirectly through a complex sequence of many steps?

30. Define the following terms: chemiosmosis, redox, chlorophyll, proton pump, ATP synthase.

31. Distinguish between the light-dependent ("light") reactions and light-independent ("dark") reactions of photosynthesis.

32. List and discuss two ways in which cyclic and non-cyclic photophosphorylation differ.

33. Discuss the key role of the enzyme known as "rubisco" in the Calvin-Benson cycle. What is carbon fixation? Which high-energy molecules are utilized in large quantities in the Calvin-Benson cycle? Why is the metabolically intermediate molecule G3P so important?

34. What is photorespiration, and what kinds of plants are most vulnerable to it?

35. Some plant species avoid the energetic inefficiencies associated with photorespiration. List two such types of plants. Why is the "storage" of carbon (from carbon dioxide) as a 4-carbon molecule helpful to these plants?

Lecture title: Cellular Respiration

36. GUIDING QUESTION: The cells of all animals (and humans) engage in cellular respiration, which is responsible for supplying vast quantities of energy-rich ATP that is used to maintain high activity levels. Cellular respiration in animals and plants always requires oxygen gas, which of course is found in air. However, oxygen gas was not always present in air. During this period of history, all life forms on Earth were microbes (for example: bacteria). Certain types of microbes, over millions and millions of years, transformed the chemical content of air into an oxygen-rich mixture. This is a truly global, mighty feat for such small microorganisms to pull off. What types of microbes are responsible for this transformation on our planet? If air did NOT contain large amounts of oxygen even today, would animals and humans still be able to have evolved and survived? Why or why not?

37. REVIEW the inverse relationship between cellular respiration and photosynthesis and which types of organisms utilize these two very important metabolic pathways.

38. Cellular respiration consists of the following: an electron transport chain, intermediate step, Krebs cycle, glycolysis (but not in this order). List these four sub-pathways of cellular respiration in their proper order. Which of these four sub-pathways also occurs in fermenting organisms? How does fermentation differ from cellular respiration?

39. List and discuss the processes underlying each of the two types of phosphorylation (and means of producing ATP) that are employed in cellular respiration. Which of these types forms ATP directly? Which of these two types forms ATP indirectly?

40. What important electron carrier is most commonly used in cellular respiration during the oxidation of glucose?

41. Summarize (a) the preparatory stage and (b) energy-conserving stage of glycolysis. What crucial molecule is formed as a result of (a)? Which molecule is formed as a result of (b)? What is the net production of ATP during glycolysis as a whole? Which type of phosphorylation (see #3 above) is used to form ATP during glycolysis?

42. Which chemical reaction in glycolysis is catalyzed by the enzyme known as pyruvate kinase? List the reactants and products of this important chemical reaction.

43. The so-called intermediate step links together which two sub-pathways of cellular respiration? Which molecule joins with coenzyme A (coA) during the intermediate step? Are any ATP produced during the intermediate step? Are any NADH produced during the intermediate step?

44. Define chemiosmosis. Summarize the key features of chemiosmosis. (NOTE: the animation posted on Aggie Scholars may be very helpful here.)

45. In which areas of the cell do (a) glycolysis, (b) the intermediate step, (c) Krebs cycle, and (d) the electron transport chain occur in prokaryotes? In eukaryotes?

46. What is the difference between aerobic cellular respiration and anaerobic cellular respiration?

47. What other types of biomolecules (other than sugars, such as glucose) are commonly catabolized in cells to yield ATP?

48. Define anabolism. List the four major biomolecules that cells are constantly manufacturing through anabolic processes that require large amounts of ATP.

49. What is the overall difference in the efficiency of cellular respiration compared to that of fermentation, in terms of ATP production per glucose molecule?

50. What is fermentation? What important electron carrier is utilized in fermentation? Which type of phosphorylation (see #3 above) is utilized during fermentation?

51. List at least two common chemical by-products of fermentation in microbes (bacteria and yeasts).

Lecture title: Cellular Reproduction: Mitosis

52. GUIDING QUESTION: TP stands for tumor protein. The human gene known as TP53 encodes the critically important protein called p53, which plays a primary role in suppressing tumors (cancer). This protein regulates the cell cycle, which includes G1, S, G2, and mitotic phases. Does it make sense that a cell cycle regulating protein would be important in preventing cancer? Why or why not? (In your answer, be sure to comment on the basic problem of cancer. That is, what is the basic difference between a cancerous cell and a non-cancerous cell? Or, put differently, what is a tumor made of primarily?)

53. Mitosis occurs in eukaryotic cells. Bacteria do NOT undergo mitosis. What form of asexual reproduction occurs in bacteria? How is this process different from mitosis? Are there any similarities to mitosis?

54. Distinguish between chromatin and chromosome. When do chromosomes first form? Why is the DNA in chromosomes packaged so extremely densely?

55. What is a karyotype? Give one example of a human condition associated with abnormal chromosome number.

56. Is there a simple, direct relationship between the number of chromosomes and the total number of genes, or complexity of the cell or organism?

57. What is a homologous chromosome? Distinguish between autosomes and sex chromosomes. What is a (sister) chromatid?

58. Describe the fundamental features of the eukaryotic cell cycle. (Drawing a diagram may be helpful.) Cells spend most of their time in what (non-mitotic) phase? What is the phase of the cell cycle in which DNA is synthesized?

59. List and describe the major features of the mitotic phase of the cell cycle.

60. Cytokinesis refers to an event that is separate from mitosis. What is cytokinesis? What is a cleavage furrow? Which mitotic phase does it typically overlap with?

61. What is a cell plate? How is it formed, and how does it contribute to cytokinesis in plants?

Lecture title: Cellular Reproduction: Meiosis

62. GUIDING QUESTION: The sex cells of animals and humans (sperm and egg) are generated through a process of cell division known as meiosis. Although the amount of nuclear genetic content is equivalent, egg cells and sperm cells differ in many other ways. In particular, only one of these cell types provide mitochondria, and therefore mitochondrial DNA, to a fertilized zygote. Which of these cell types provides all of the mitochondrial DNA to human offspring? That is, is mitochondrial DNA inherited maternally or paternally? Provide one reason why this might be the case.

63. All of your cells have the same __________. Half of each person's genome comes from the _______ and half from the _________.

64. Define genetics. Name the two (eukaryotic) processes in which genetic information is passed on to newly formed cells.

65. Distinguish between somatic cells and germ cells. In your response, use the terms diploid (2N) and haploid (1N). What is a gamete?

66. What is meant by the term "junk DNA?" Is there a direct intuitive relationship between the number of genes, or the number of chromosomes, that a eukaryotic species possesses and the level of biological complexity of that species?

67. Define meiosis. What is the purpose of meiosis? Is meiosis involved in sexual or asexual reproduction?

68. What is the diploid state (number of chromosomes) and haploid state in humans? How is this related to the nature of fertilization and zygote formation in humans?

69. Meiosis consists of two meiotic sub-events known as Meiosis I and Meiosis II. Why is Meiosis I termed a "reduction division?" Why is Meiosis II termed a "mitotic division?"

70. List and describe the cellular activities occurring during Meiosis I and Meiosis II.

71. What is "crossing over?" What is "independent assortment?" At what stage in meiosis do these phenomena occur?

72. List the primary differences between mitosis and meiosis (e.g., in ploidy, number of cells produced, and the function of those cells that are produced).

73. List three types of genetic mutations and describe the potential effects on protein structure. (REMEMBER: The central dogma of biology holds that one gene codes for one protein.)

74. Do chromosomal rearrangements have significant effects on protein production and protein structure?

75. How many different combinations of chromosomes are possibly formed during meiosis (in humans)? Do the effects of crossing over and genetic mutation further increase this potential for genetic diversity or reduce this genetic diversity?

76. What is fertilization? Which chromosomes determine the sex of offspring (in humans)?

Attachment:- Human Biology.rar