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Exam 4 Notes 10 28 13 Topic 12 Movement of Gases in Animals 1 fish O2 2 big problems water in out gill special adaptation Counter Current Gas Exchange special cases 2 Hb affinity and hi affinity for O2 blood pH in lung capillaries always high in 2 3 Hb low affinity for O2 blood pH in body cells always low in 2 special cases 4 Hb and SCD disease of Hb effect in blood resistance Daily Question It s time to get back to our fish Consider lake or seawater flowing over the capillaries in the fish gill both liquids flowing at the same rate and in the same direction Assume that the water has 100 of its O2 carrying capacity and that the blood has no O2 because it came into the gill after interacting with all the body cells By the time the blood leaves the gill and re enters the main body of the fish what is its maximum O2 content Water and blood moving next to each other oxygen will diffuse from the 100 in the water to the 0 in the blood until they are equal that will be 50 Fish Counter Current Gas Exchange See diagram This is what happens in the fish gill Water and blood move in exact opposite directions Also happens in some birds that fly at extremely high altitudes We as humans do not have such a fancy mechanism in our lungs Hemoglobin s Affinity Hemoglobin s holds he oxygen When there is no oxygen it can sometimes hold CO2 The hemoglobin is pH dependent When the pH of the blood is high then the affinity of the hemoglobin for the Its job is to pick up oxygen and deliver it oxygen is high We as humans want the hemoglobin to have a high affinity in the lungs pH must be very high in the lungs we know it is high because the carbonic acid disappeared the CO2 came out of the blood Hemoglobin affinity varies in the body Lungs it is high In the body organs and rest of the body when that blood comes form the heart because of lots of oxygen on the hemoglobin CO2 diffuses into the blood diffusion gradient when the CO2 moves into the blood plasma cytosol red blood cells forms acid lowers the pH so the oxygen can diffuse into the cells Two Major instances where Organisms hemoglobin have an extremely affinity for oxygen mountain tops 10 000 feet 15 000 feet oxygen concentration is a lot lower than this implies that oxygen is difficult to get high altitudes high elevations down here marmots occur in the mountains they evolved at high elevations their hemoglobin has a very high affinity for oxygen much higher than ours llamas evolved hemoglobin extremely high affinity for oxygen big animals in the Himalayas evolved at 15 000 20 000 feet oxygen concentration really low high affinity mountaineers that climb the mountains what about their hemoglobin Exactly the same as ours they have to go to thee areas weeks in advance to get acclimated to the altitudes getting their blood to hold more oxygen what happens during this acclamation period They produce more blood cells women studying Tibetans some mothers were much more successful in pregnancies with fewer complications than most other moms 24 000 feet only some women were better at this and their children healthier discovered in these women s breaths high nitric oxide concentration important molecule in human health they had more of this in their body what does nitric oxide do in the body it enlarges the arteries dilates these women are delivering more blood to the fetus more blood more oxygen these women s children are doing the same natural selection is occurring because they have a gene that produces more nitric oxide their children are getting the gene a population will get that gene evolution is occurring Lance Armstrong stripped of his medals taking drugs to increase the production of red blood cells he was blood doping what athletes used to do two weeks before an athletic event remove a quart of blood and put it in the fridge morning of the event inject the blood back in more of everything in that blood blood doping Second situation trouble getting oxygen human fetus we all about 1 of our hemoglobin is still fetal the mother has her oxygen held by her hemoglobin how does the fetus get it fetuses fetal blood have a higher affinity for oxygen than we do now fetus blood produce special kind of hemoglobin called fetal hemoglobin this allows the fetus to strip the oxygen off the mothers hemoglobin Two well known instances when hemoglobin affinity is lower than normal why would this be beneficial Their body cells need more oxygen so it is easier for the oxygen to come off 2 instances 1 small mammals have a higher respiration weight per pound than large mammals why More glycolysis more ETS more ATP more oxygen low affinity for hemoglobin for oxygen cannot deliver fast enough unless you lower the affinity smaller mammal has a higher demand because they are respirating at a higher rate 2 Reptiles amphibians turtles lizard they are cold blooded they do not generate heat in their bodies if its cold outside the oxygen will not easily come off the hemoglobin so these animals have evolved a low affinity for hemoglobin so they can get the oxygen more easily Sickle Cell Anemia Bad hemoglobin More comes in Africans and African Americans occurs in whites as well but not Hemoglobin is improperly constructed Hemoglobin has 600 amino acids moderately sized protein 4 irons stuck on very frequently the protein Bad gene that makes 1 amino acid wrong 1 out of 600 wrong can kill you Makes faulty hemoglobin If lots of oxygen in the blood the hemoglobin is okay But when there is low oxygen in the blood might occur at high elevation excessive exercise hemoglobin instead of normal protein it crystallizes into a crystal cannot hold oxygen Even worse part it turns into a sickle shape that sickle shaped red blood cell cannot get through the capillaries blood flow stops Brain strokes Some people have the full disease but never symptoms they produces a large amount of fetal hemoglobin has adults Caused by a defect in the hemoglobin One gene that is wrong makes one amino acid wrong 1 mistake can kill you 15 of their hemoglobin is fetal in individuals that have the genetics for the disease but no symptoms BCL11A when this gene is turned on it makes adults make fetal hemoglobin We may be able to take someone with the full disease of it tweak the gene and cure them of the disease 10 30 13 Notes Topic 12 Movement of Gases in Plants 1 Bean and gases no pumps delivery diffusion 2 CO2 O2 resp n vs photosynthesis net gases in green non green parts 3 O2 uptake underwater organs adaptns

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