BISC 307L 1st Edition Exam 1 Study Guide I EVOLUTIONARY PERSPECTIVES Extra information that is useful Blackboard resources he posted 1 What are the five features of physiological control systems o 1 Tonically Active o 2 There is a set point that can be altered i e body temperature o 3 They are redundant and antagonistically arranged o 4 They anticipate change o 5 Positive feedback brings about positive change 2 What are the basic principles of EVOLUTION o A Evolution is decent with modification o B Outcome is an organism matched to its environment o C This matching optimizes reproductive success called FITNESS Results within a population optimize average fitness o D Results do not optimize life span or general health o E Natural selection is driving force 3 What were Darwins 5 observations o 1 Species produce more offspring than the environment can support o 2 There is always variation within a population with the ability to compare for resources survive and reproduce o 3 Some variation is inherited due to mutations recombinations and epigenetic modifications o 4 Natural selection happens because of these differences o 5 Selection leads to evolution in population 4 Define FITNESS o the probability that ones genes will be passed on to the next generation Selection can only maximize reproductive fitness Does not require long life 5 What is the difference between the proximate and ultimate reasons for why we get sick o Proximate reasons pathophysiology looking at the specific mechanisms of how we get sick o Ultimate reasons Why has evolution left us so vulnerable to disease Evolutionary medicine 6 What are the 4 ultimate reasons for why our bodies are vulnerable to disease o 1 Selection is about fitness not health and well being o 2 Constraints and tradeoffs inevitable and we must work with what we had before bislagiatt o 3 Human evolution is too slow to cope with challenges of changing environment we are not evolving in isolation but in concert with our pathogens and predators o 4 Our evolved defenses may be harmful or seem harmful i e allergic reactions autoimmune disease fever 7 What are 5 examples of human design flaws and why do we still have them o 1 Humans are bipedal and have large brains but small pelvis Compromise big brains mean babies head is big but cannot be fully developed because babies are altricial Narrow pelvis allows us to stand upright but is just wide enough for underdeveloped baby brain o 2 The appendix isn t necessary Was probably used to help digest cavemen food at one time o 3 We cannot synthesize vitamin C due to our ancestors eating a lot of fruit o 4 Our retina is inside out and light must pass through upside down to get to the light sensitive cells nerves and blood vessels supply from the outside o 5 We have a crossing of esophagus and trachea leading to choking probably evolved from lungfish 8 Explain 2 examples of evolutionary mismatch o 1 Lactose intolerance babies can digest milk but 70 of adults cant Probably due to lack of cattle causing a mutation and then reintroduction of cattle causing second mutation so that some adults can digest milk but others cannot o 2 Food availability and metabolism used to have ot survive food scarcity so we needed mechanisms that stored food but now these mechanisms aren t needed and storage of excess food becomes obesity 9 True or False Pathogens evolve slower than humans o false Humans evolve slower This can be seen in drug resistance of pathogens 10 What concept explains immune system developmental plasticity o hygiene hypothesis in order for the immune system to develop its regulatory mechanisms it needs to undergo certain exposures during development Without being challenged by normal pathogens the immune system doesn t develop its full regulatory path look at parasitic worms example with IgE II MEMBRANE DYNAMICS Figures that are important GLUT transporter Slide 5 and 6 Slide 8 of cell communication lecture helpful 1 What are the 6 ways to transport substances across membranes o 1 Direct o 2 Facilitated Diffusion passive o 3 Osmosis passive o 4 Ion Channel o 5 Active transport o 6 Exocytosis and endocytosis bulk transport 2 What factors affect diffusion o 1 Concentration o 2 Distance o 3 Temperature o 4 Cross sectional area o 5 Molecular size o 6 Lipid solubility 3 Explain facilitated diffusion and give an example o diffusion that is simply due to the bidirectional transport of particles passively due to concentration difference Like pac man ex GLUT transporter 4 Explain primary active transport and the four forms o These are also called pumps or ATPases and they move particles against their electrical or chemical gradients Two antiports and 2 uniports 1 Antiport 1 Na K ATPase 3Na out for 2K in which makes it electrogenic makes resting potential more negative 2 Antiport 2 H K ATPase 3 Uniport 1 Ca2 ATPase 4 Uniport 2 H ATPase 5 Explain secondary active transport and list all 8 types o Energy given up as ion moves down its electrochemical gradient is coupled to and powers the movement of another substance against its electrochemical gradient Secondary because the ATP comes from other ions and is used to transport ions out or in 4 Antiports and 4 Symports Antiports opposite directions 1 3Na Ca2 electrogenic Na in 2 Na H Na in 3 H K H in 4 Cl HCO3 Cl in Symports same direction 1 Na Cl in 2 Na K 2Cl in 3 K Cl out driven by K gradient 4 Na Sugars AAs NTS in 6 What is the difference between the apical side and basolateral side of epithelium o Apical lumen side and Basolateral blood side 7 Explain Glucose reabsorption in the kidney or intestine o Discussing a cell lining the kidney or small intestine the cell needs to take up glucose and transport it to blood basolateral side when there is low blood glucose concentration This is called reabsorption This is driven by the Na K pump where o 1 K comes in from the blood to the cell and moves through K channels on apical membrane o 2 This creates an electrochemical gradient for sodium to move in through the Na glucose symporter in the apical membrane since Na concentration is low inside the cell and this drives in glucose with it against glucose s concentration gradient o 3 Glucose moves down concentration gradient through GLUT transporter in basolateral membrane to blood o 4 Na goes passively through Na K ATPase into blood and diffuses this mechanism is also important for K secretion look at slide 6 for picture 8 Explain H2O and NaCl transport in the lung or colon o