Test # 4 (final): Study questions

Recommended reading: Willmer et al. Environmental Physiology of Animals. 2nd edition.
Part 8. Temperature and its effects.
Part 10. Hormones and chemical control systems.
 

Test format: 4 essay 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

  1. Define temperature and its effects of the physical properties of the environment (viscosity, solubility of gases, diffusion rates, phase transition of water). What implication these physico-chemical changes have for living organisms?

  2. Define activation energy of chemical reaction and explain how 1) temperature and 2) enzymes affect it. Explain what Q10 is and be able to calculate rate of a reaction given a change in the temperature and the value of Q10 (hint: for this exercise, I will only be using temperature changes in 10 degree Celsius increments).

  3. Define optimum, pejus, critical and lethal temperatures, and explain what physiological changes occur at the whole-organism and cellular levels in each temperature range. List adaptations that play the most prominent role in pejus, critical and lethal temperature range.

  4. Explain homeoviscous membrane adaptation and its physiological consequences to an organism. Describe changes in membrane composition and fluidity during adaptation to warm and cold climates. Name an enzyme that plays a key role in homeoviscous adaptation and explain what it does.

  5. Explain how mitochondrial abundance and function assists in adaptation and acclimation do different temperature regimes. Explain how increase in mitochondrial density affects critical temperature of an organism and why?

  6. Explain the role of anaerobiosis and HIF-1 pathway in adaptations to critical temperatures. How does acclimation and acclimatization to different thermal regimes affect critical temperatures?

  7. Describe the mechanisms of function of heat shock protein (HSPs) and explain their role in cellular protection against heat stress. describe the pathway involved in transcriptional regulation of HSP levels in the cell.

  8. Compare freeze avoidance and freeze tolerance strategies of adaptations to extremely low temperatures. Define supercooling and explain how it assists in protection against low temperature stress. Define ice-nucleating proteins, and colligative and non-colligative cryoprotectants; which role do they play in supercooling and adaptation to low temperature stress? Describe ho extracellular formation of ice in freeze tolerant organisms protects against cellular damage.

  9. Define antifreeze proteins and describe their mode of action. Where are they found? What structural properties of antifreeze proteins make them useful for freeze avoidance?

  10. Define different types of chemical signaling (autocrine, paracrine, endocrine, neuroendocrine, neural and exocrine).

  11. List main groups of hormones and give examples.

  12. Describe and compare the mechanisms of action of lipid-solubel and lipid-insoluble hormones. Be specific and make sure you describe all intracellular events in target cells in response to a hormone including receptors and their localization, secondary messengers, signal transduction mechanisms and gene activation mechanisms. Give examples.