Test # 3: Study questions
Recommended reading:
Willmer et al. Environmental Physiology of Animals. 2nd edition.
Part 4. Water, ions and osmotic problems.
Part 5. Animal Water Balance, Osmoregulation and Excretion.
Part 7: Respiration and Circulation
Test format: 4 essay questions (30 pts each), 6 short-answer questions or definitions (5 pts each). One essay question will be based on the topic of your team presentation in class.
Important: You can bring 1 (one) standard bibliographic card (4 x 6 inches; I will check the dimensions) with as much information as you can fit on it and use it during the test. The only other allowed tools are a standard stand-alone calculator (not the cell phone) and pen or pencil. Good luck!
Study questions
Name and briefly describe the main type of animal oxygen-carrying pigments in terms of composition of their active center, O2 capacity, type of binding, localization and taxonomic distribution. What is P50 of a O2-binding pigment? Be able to determine P50 for the oxygen binding curve of a pigment.
Compare major characteristics of adult myoglobin and hemoglobin, and of adult and fetal human hemoglobin in terms of their O2 affinity, responses to pH and allosteric modulators, and explain how these characteristics are adapted to specific physiological functions carried out by these protein.
List and explain functional changes in respiratory and circulatory functions during acclimatization to high altitude hypoxia. Compare adaptations of Tibetan and Andean high altitude populations to the altitudinal hypoxia. What is similar or different between the two? List physiological changes that are shared between acclimatization and long-term adaptation responses to high altitude in humans, and those that are unique to the adapted populations permanently living at high altitude.
Describe the effects of temperature, CO2 and pH on O2 binding to hemoglobin. What is Bohr effect and Root effect?
Describe mechanisms of CO2 transport in the blood.
Describe the physico-chemical properties of water and their implications for biological systems. Define chaotropic and kosmotropic solutes and give an example. How these solutes affect properties of the water and proteins?
Define osmosis and describe major passive and active mechanisms of water and solute transport across the cellular membrane (make sure you distinguish between primary and secondary transport).
Describe main osmoregulatory mechanisms and strategies of osmoregulation in originally marine organisms, terrestrial (originated from marine or freshwater life forms), brackish water, fresh water, and secondary marine invaders. Explain what osmotic challenges they face and how these are overcome.
Define hypo- and hyperosmotic osmoregulators and osmoconformers. Give examples of each category.
Explain mechanisms and physiological advantages of cell volume regulation. What are the major organic and inorganic osmolytes involved in osmo- and cell volume regulation? Give examples of animals that use different types of osmolytes. What are advantages, disadvantages and limitations of using organic vs. inorganic osmolytes? Explain how Na+ acts as a cellular signal for cell volume regulation, and list major steps involved in cell volume regulation, enzymes responsible for it and the direction of change in response to increase or decrease in Na+ levels (Fig. 4.20 in your textbook).
Define compatible and counteracting osmolytes and give examples. Explain how TMAO counteracts effects of urea in elasmobranchs and mammalian renal tissue.
What are the major physiological adaptations to osmotic hyporegulation or hyperregulation? Describe structure, mechanisms of function of chloride cells and their role in whole-organism osmoregulation.
Describe structure and function of ultrafiltration-based and secretion-based kidneys. What are advantages and limitations of each mechanism?
Explain the principle of compartmentalization in osmoregulatory organs and explain how compartmentalization helps in water reabsorption.
Explain the principle of countercurrent in osmoregulatory organs and explain how it helps in water reabsorption and production of hyperosmotic urine. Use mammalian kidneys and Malpighi tubules of xeric insects as examples.
List different nitrogen excretion products and compare their advantages and disadvantages in different environments.