Test # 2: Study questions
Required reading:
Willmer et al. Environmental Physiology of Animals. 2nd edition.
Chapter 7.4.5 Blood vessels
Recommended reading:
Willmer et al. Environmental Physiology of Animals. 2nd edition.
Part 6: Metabolism and Energy Supply
Part 7: Respiration and Circulation
Test format: 4 assay questions (30 pts each), 6 short-answer questions or definitions (5 pts each).
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
Describe cellular functions of ATP and phosphagens. What are examples of major types of animal phosphagens and what is adaptive significance of different phosphagens?
Define aerobic and anaerobic metabolism, and different types of aerobes and anaerobes (obligate, facultative). Why oxygen is toxic? Explain major pathways of formation of reactive oxygen species (ROS) in animals, name main ROS types and enzymes involved in their detoxification.
Describe major biochemical steps and the summary equation of glycolysis. What are the starting substrates of glycolysis? What is the end product and ATP yield of the typical vertebrate glycolysis? Describe key regulatory steps of glycolysis, which enzymes are involved (HK, PFK and PK) and how they are regulated.
Describe alternative anaerobic pathways in animals; what are their end products, ATP yields and adaptive significance? Make sure you can give examples of animal groups that have certain anaerobic pathways.
Describe the major pathways of substrate oxidation and oxidative phosphorylation in mitochondria. Name and describe the function of mitochondrial complexes I through V. Describe the chemiosmotic theory of ATP synthesis. define protonmotive force (p), write a formula for it, and describe contribution of electrochemical and pH gradients to protonmotive force. How does proton motive force couple substrate oxidation and ATP synthesis in mitochondria? What creates and what dissipates proton motive force?
Compare three major types of fuels (carbohydrates, lipids and amino acids) that can be used by mitochondria to drive oxidative phosphorylation. Compare the advantages and disadvantages of different fuels (caloric value, storage capacity, ATP yield, how quickly they can be mobilized into mitochondria) and explain under which physiological conditions certain fuels are predominantly used. Explain how respiratory quotient can be used to determine which fuel is oxidized by mitochondria.
Describe the points of entry (metabolic intermediates) of different fuels (carbohydrates, amino acids and lipids) into Krebs cycle and describe how the rate of supply of these fuels to Krebs cycle is regulated.
Define proton leak. Describe and explain physiological functions of proton leak (endothermic thermoregulation, antioxidant defense).
Describe the molecular mechanisms of oxygen sensing via HIF pathway and how HIF coordinates cellular response to hypoxia.
Define metabolic rate depression and how it improves survival of extreme stress in animals. List and describe four major mechanisms that aid in metabolic rate depression (protein phosphorylation, regulation of signal transduction pathways, dissociation of glycolytic complexes, expression of stress-specific protein isoforms); give examples.
Write an equation of individual energy budget of an organism and explain each term.
Define specific dynamic action, assimilation efficiency and compare food assimilation efficiencies in organisms with different feeding strategies (herbivores, carnivores, detritivores, etc. - see lectures for the complete list).
Write the equation for Fick's law of diffusion and explain each term in it. Which terms can be modified to improve diffusion rates by adaptation? How is diffusion limited by the size of an organism?
Define oxyconformers, oxyregulators and describe critical oxygen tension (PO2). Describe how critical PO2 differ in organisms adapted to different environments (in terms of environmental oxygen levels) and how specialized respiratory and circulatory system affect the breadth of the range of PO2 where oxyregulation is possible.
Describe and compare three major types of respiratory structures in animals; give subtypes and examples of animals that possess them. How these structures aid in oxygen diffusion?
How does ventilation aid in O2 diffusion (think forced convection). Describe passive and different types of assisted ventilation. Be able to give specific examples with explanations (e.g. passive ventilation in sponges, assisted ventilation in sponges, mollusks, insects, fish, mammals and birds).
Give examples of open, pool, countercurrent and crosscurrent arrangements in gills and lungs and explain efficiency of different arrangements in terms of gas extraction. Be able to draw the graphs of changes in blood and external media PO2 for each type of arrangement.
What is the main function of circulatory systems? Compare open and closed types of circulatory systems; give examples of animal groups that possess them. Compare major circulation patterns in vertebrates and invertebrates.
What is a heart? Briefly describe morphology and function of invertebrate hearts using insects and mollusks as example. Explain evolutionary changes in heart morphology and circulation patterns in vertebrate lineage (fish, amphibians, reptiles, mammals and birds) and how they relate to activity levels and terrestrial life style of animals. What is cardiac shunting?
Define and describe different types of blood vessels (elastic and muscular arteries, arterioles, capillaries, venules, veins). Describe how blood pressure changes from arterial to venous side of the circulation. Give the equation determining blood pressure in blood vessels, and describe how vessel resistance (and thus blood pressure) can be regulated via endothelin-1 - NO system.