bio final exam review

bio final exam review - Study guide Exam 5 What are the...

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Study guide Exam 5 What are the respiratory exchange gases and where do they come from? Oxygen : from the environment to produce adequate supply of ATP by cellular respiration. Carbon Dioxide : is the end product of cellular respiration and it must be removed from the body to prevent toxic effects. What determines the direction of flow of gases? What is the problem at high elevations? Diffusion is the only means by which gases are exchanged between the internal body fluids of an animal and the outside medium. There is no active transport mechanisms to move gases across bio membranes. Diffusion results from the random motion of molecules, the net movement of a molecule is always DOWN its concentration gradient. High elevations has a partial pressure of oxygen about 1/3 rd less than that at sea-level and the gas exchange depends on the pressure difference between the air and the body fluids. So the reduction of pressure at high altitudes constrains oxygen intake. What are the factors that influence diffusion and what are the adaptations of the respiratory system to maximize diffusion? Partial pressures of the gas at the location The rate at which a gas like O2 diffuses between 2 locations The diffusion coefficient, which is the characteristic of the diffusing substance, the medium, and the temperature. The cross-sectional area through which the gas is diffusing the path length, or distance, between the two locations To maximize : use air rather than water as their gas exchange medium when possible; remain at low altitudes, increase the surface area of the respiratory organs, minimize the path length, ventilations and perfusion Why is it more difficult to get oxygen from water than air? The oxygen content of air is much higher then the oxygen content of an equal volume of water. Oxygen diffuses about 8,000 times more rapidly in air than in water More energy is required to move water than to move air because water is 800 times more dense than air and about 50 times more viscous. What are the respiratory systems of insects? The tracheal system that enables insects to exchange gases extends to all the tissues in the insects body. So gases diffuse through air most of the way to and from every cell. Insect’s respiratory system communicates with the outside environment through gated openings called spiracles in the side of their abdomen. Spiracles: open to allow gas exchange, and then close to decrease water loss. The open into tubes called tracheae that branch into even finer tubes called tracheoles until they end in tiny air capillaries. How does gas exchange occur in fish and birds? How are they similar and how are they different? Fish:
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This note was uploaded on 01/27/2009 for the course BIO 1407 taught by Professor Subramanian during the Spring '09 term at Collin College.

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bio final exam review - Study guide Exam 5 What are the...

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