Maintaining a balance

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Maintaining a balance

  1. 1. 9.2 Maintaining a Balance• Most organisms are active in a limited temperature range• Plants and animals transport dissolved nutrients and gases in a fluid medium• Plants and animals regulate the concentration of gases, water and waste products of metabolism in cells and in interstitial fluid
  2. 2. Enzymes
  3. 3. Identify the pH as a way of describing the acidity of a substance pH is a the amount of hydrogen ions measured in a substance (solution) pH of 7 is neutral e.g. water, 0-6 is acidic .e.g. lemon juice, 8-14 is basic .e.g. sodium bicarbonate
  4. 4. Explain why the maintenance of a constant internal environment is important for optimal metabolic efficiency Cells work best under their optimum conditions- right pH, temperature and the best concentration. Enzymes control all metabolic processes in the body Enzymes work in an environment where they’re optimum temperatures and pH conditions are met. At temperatures and pH values other than the optimum, the enzymes fail to work as efficiently as they should or not at all.
  5. 5. Metabolism
  6. 6. Describe homeostasis as the process by which organisms maintain a relatively stable internal environment In order to maintain maximum efficiency of an enzyme, the body must maintain a stable/ constant internal environment. This is known as homeostasis. Homeostasis is the process by which the internal environment is kept within normal limits regardless, of the external environmental conditions. This includes temperature, pH, gas levels, water and salt concentrations. This allows the enzyme’s optimal conditions to be met and the body to work efficiently and kept stable
  7. 7. Homeostasis
  8. 8. Explain that homeostasis consists of two stages: Detecting changes from the stable state Counteracting changes from the stable state Detecting changes- Receptors detect changes to the normal internal environment. e.g. sensory neurons in the skin pick up a decrease or increase in temperature of air surrounding the body. Counteracting changes- After the receptors have detected these changes, action is taken to counteract these so that homeostasis is maintained. These are done by effectors. e.g. shivering to generate heat in muscles.
  9. 9. Outline the role of the nervous system in detecting and responding to environmental changes The co-ordinating system in humans is the nervous system. The nervous system consists of the central nervous system (CNS) and the peripheral nervous system (PNS). The CNS consists of the brain and spinal chord and the PNS consists of the sensory nerves and the effector nerves. When the environmental temperature begins to exceed a comfortable level for the body. The stimulus is detected and the sensory neurons send an impulse to the brain where the information is interpreted and a response is initiated. This response is then sent to the effectors. Example- Temperature sensors in the skin detect the temperature change (the stimuli) and a sensory neuron conducts a nervous impulse to the hypothalamus found in the brain. Nerve impulses pass this response from the receptors to effector neurons then onto effectors, such as blood vessels, sweat glands, endocrine glands and muscles. This is when we shiver to try and generate heat. (counteract the stimuli)
  10. 10. Identify the broad range of temperatures overwhich life is found compared with the narrow limits for individual species Life forms can found in the temperature range of –40ºC to 120ºC Majority of life forms are in the –2ºC to 40ºC temperature range and is narrower for each individual species. Below 0ºC cell risk ice crystals forming and above 45ºC causes them to denature.
  11. 11. Compare responses of named Australian ectothermic and endothermic organisms to changes in the ambient temperature and explain how these responses assist temperature regulationEndotherms Regulate body temperature using metabolism homeostasis. (birds and mammals) Insulation- control of blood flow (capillaries dilate to keep you cool), evaporation (humans sweat to keep cool), counter-current exchange (blood vessels placed together and chilled bloody returning from veins gets heated up) and metabolic activity (during hotter weather metabolism slows down {by product of this HEAT}) are ways that endotherms control their body temperature. In hot conditions~ Example (1) Red kangaroo licks the inside of its paws, where skin is thinner, and blood supply is closer to the surface, so that heat can be easily dumped to the outside. Evaporation from saliva promotes the loss of heat from the blood. Example (2) The large ears of the rabbit-eared-bandicoot provide a large surface area to pass excess heat when it is burrowing during the heat of day and when it is active at dusk.
  12. 12.  Ectotherms- Body temperature fluctuates, according to ambient temperatures. (reptiles) Hibernation- nocturnal activity, controlling exposure and migration are ways that ectotherms control their body temperature. In cold conditions~ Example (1) magnetic termites (Amitermes meridionalis) pack the walls of their mounds with insulating wood pulp and align their mounds north- south to maximise exposure to the sun in the mornings and the evenings when the air is cooler and to minimise exposure during heat of day. Example (2) Bogong moths are able to avoid their bodies freezing by supercooling their tissues. This process involves reducing the temperature of the body fluids below their usual point of freezing and as a result, ice crystals do not form and destroy the cells.
  13. 13.  Characteristics of ectotherms and endotherms:Behavioural adaptations: Migration Hibernation and aestivation Sheltering Nocturnal activity Controlling exposureStructural adaptations: Insulation Physiological adaptations: Metabolic activity Control of blood flow Counter-current exchange Evaporation
  14. 14. Animal Behaviour
  15. 15. Identify some responses of plants to temperature change Plants can be damaged at temperature extremes when enzyme structures are altered or membranes change their proteins. As many enzymes are involved in photosynthesis and respiration temperature extremes can be a major problem. In cold conditions, extracellular ice formation causes dehydration. Some plants can tolerate temperatures as low as -50ºC by altering the solute concentrations and through lack of ice-nucleating sites in cells to prevent intracellular freezing. In hot desert conditions, plants develop a compromise between access to gases for photosynthesis and access to gases for respiration by keeping their stomates open and cooling by evaporation. This risks dehydration.
  16. 16. Alpine Plants
  17. 17. Desert Plants
  18. 18.  In hot or cold plants may die but leave dormant seeds so to keep the flow going. They may die above the soil but leave their roots embedded in the ground so that they can keep living when conditions are good. Too high temperatures during flower formation may cause poor crop Some seeds may only germinate after a fire. Example (1)- eucalyptus leaves grow vertically to reduce exposure to the sun. Example (2)- porcupine grass-sand in central Australia have curled leaves that opens up after rain-exposing the stomata. In dry conditions the leaf curls up, burying the stomata and reducing transpiration ... conserving water.
  19. 19. Porcupine grass
  20. 20. Identify data sources, plan, choose equipment or resources andperform a first-hand investigation to test the effect of:Increased temperatureChange in pHChange in substrate concentrations on the activity of namedenzyme(s) FACTOR EFFECT ON ENZYME ACTIVITYIncreasing temperature Increases activity of the enzyme until it denatures. They have an optimum temperature.Change in pH Depends on the enzyme. Each enzyme has they’re own optimum pH and it may denature.Change in concentration The higher the concentration the faster the of the substrate reaction rate. The rate of reaction is limited by the amount on enzyme present. (still works after saturation point)
  21. 21. Enzyme Affectors
  22. 22. Lipase investigation Effect on temperature Aim: to determine the relationship the relationship between the effect of temperature and the activity of the enzyme, lipase Hypothesis: the enzyme lipase works best at a temperature of 35-40ºC. Apparatus: Full fat milk 8 test tubes Test tube rack 5% lipase solution 0.05M sodium bicarbonate solution Phenolphthalein Thermometer Large beaker with water Hot plate Measuring cylinders Stopwatch Pipettes
  23. 23.  Method: Place 50g of ice into a large beaker and test tubes 1 and 2 which contain 1ml of milk in each test tube. Record the temperature. Then add 11mls of sodium bicarbonate solution and 5 drops of phenolphthalein to each test tube. Add 1ml of lipase solution to test tube 1 and start timing. Note the colour changes of the solutions at I minute intervals for 5 minutes from the time of addition of Lipase. Note: test tubes 2,4,6 and 8 are controls (.i.e. they don’t have the enzyme added to them.) Repeat steps 1-3 for test tubes 3 and 4 but this time use water at room temperature approx. 20ºC Repeat steps 1-3 for test tubes 5 and 6 but this time use a water bath set at 35ºC Repeat steps 1-3 for test tubes 7 and 8 but this time use a water bath set at 50ºC Repeat steps 1-6 three times and average your results. Collate data in a table and graph format.
  24. 24.  N.B- for the experiment to be fair the following things are to be kept constant: Lipase %: a higher lipase concentration will obviously speed up the time it takes to break down the fat. Amount of milk/ lipase/ sodium bicarbonate/ water/ ice Use the same stopwatch for each test Repeat the experiment 3 times
  25. 25. Results:Effect of temperature on the enzyme, lipase Temp 0 1 2 3 4 5Time (mins):Test tubes: (ºC)1- 0 Deep Deep Deep Deep Deep Deep Milky milky milky Milky Milky milky pink pink pink pink pink pink
  26. 26. 2- control 0 Deep Deep Deep Deep Deep Deep milky milky milky milky milky milky pink pink pink pink pink pink3- 20 Deep Deep Pale Lighter Lighter Lighter pink pink pink pink pink pink4-control 20 Deep Deep Deep Deep Deep Deep milky milky milky milky milky milky pink pink pink pink pink pink
  27. 27. 5- 35 Deep Pale Lighter Lighter Lighter White pink pink pink pink pink6- control 35 Deep Deep Deep Deep Deep Deep Milky milky milky milky milky milky pink pink pink pink pink pink7- 50 Deep Deep Deep Deep Deep Deep milky milky milky milky milky milky pink pink pink pink pink pink8- control 50 Deep Deep Deep Deep Deep Deep milky milky milky milky milky milky pink pink pink pink pink pink
  28. 28.  Conclusion: the milk solutions turn white when the lipase and milk come in contact to produce fatty acids. Sodium bicarbonate makes the solution alkaline (pink) to start with but as more acids are produced the pH drops and the solution turns white. Lipase works best at a temperature of 35ºC but beyond this denature, and becomes inactive. Active sites of enzymes have a particular shape and because of this only one substrate molecule will fit into it. When an enzyme has lost its shape because of heat, the shape of the active site changes so a substrate molecule will no longer fit.
  29. 29. Substrate Concentration Aim: to determine the relationship the relationship between substrate concentration and the effect of the enzyme, lipase Hypothesis: higher concentration milk will break down more quickly into fatty acids by the action of the enzyme lipase. Apparatus: Range of 3 different milk concentrations 6 test tubes Test tube rack 5% lipase solution 0.05M sodium bicarbonate solution Phenolphthalein Large beaker Hot plate Measuring cylinders Stopwatch Pipettes The different milks are:
  30. 30. Type of milk:Test Tube 1 and 2 1ml full fat milkTest Tube 3 and 4 0.5ml of full fat milk and 0.5ml waterTest Tube 5 and 6 0.25ml of full fat milk and 0.75ml water
  31. 31.  Method: Set up a water bath at 35ºC with test tubes 1 and 2 Then add 11mls of sodium bicarbonate solution and 5 drops of phenolphthalein to each test tube. Add 1ml of lipase solution to test tube 1 and start timing. Note the colour changes of the solutions at I minute intervals for 5 minutes from the time of addition of Lipase. Note: test tubes 2,4 and 6 are controls (.i.e. they don’t have the enzyme added to them.) Repeat steps 1-3 for test tubes 3 and 4. Repeat steps 1-3 for test tubes 5 and 6. Repeat steps 1-5 three times and average your results. Collate data in a table and graph format.
  32. 32.  N.B- for the experiment to be fair the following things are to be kept constant: Water bath at 37ºC Lipase %: a higher lipase concentration will obviously speed up the time it takes to break down the fat. Amount of milk/ lipase/ sodium bicarbonate Use the same stopwatch for each test Repeat the experiment 3 times
  33. 33. Results:Effect of temperature on the enzyme, lipaseTime (mins): 0 1 2 3 4 5Test tubes:1- high conc. of Deep Pale Lighter Lighter Lighter White milk pin pin pink pink pink k k2- control Deep Deep Deep Deep Deep Deep milk milk milky milky milky milky y y pink pink pink pink pin pin k k3- med. Con. of Deep Deep Pale pink Lighter Lighter Lighter milk pin pin pink pink pink k k
  34. 34. 4-control Deep Deep Deep Deep Deep Deep milky milky milky milky milky pink milky pink pink pink pink pink5- low conc. of Deep Deep Pale pink Pale pink Pale pink Pale pinkmilk pink pink6- control Deep Deep Deep Deep Deep Deep milky milky milky milky milky pink milky pink pink pink pink pink
  35. 35.  Conclusion: the milk solutions turn white when the lipase and milk come in contact to produce fatty acids. Sodium bicarbonate makes the solution alkaline (pink) to start with but more acids are produced the pH drops and the solution turns white. The results indicate that the higher the concentration of the substrate milk, the quicker the reaction of the enzyme, lipase.
  36. 36. Gather, process and analyse information from secondary sources and use available evidence to develop a model of a feedback mechanismSweatShiveringDecrease in temperatureIncrease in temperatureDecrease intemperatureIncrease in temperatureHypothalamus (the brain) In a feedback system, the response alters the stimulus. Feedback can be negative (when the effect of the stimulus is reduced) or positive (when the effect of the stimulus is increased). E.g. the control of hormone levels in the body, in which an increase in the level of the hormone in the blood decreases the output by the gland. A model of a feedback mechanism-
  37. 37. Analyse information from secondary sources to describe adaptations and responses that have occurred in Australian organisms to assist temperature regulation Australian Endotherm Adaptation or response to temperature organism or regulation EctothermRed kangaroo Endotherm Licks the inside of its paws, where skin is thinner, and blood supply is closer to the surface, so that heat can be easily dumped to the outside. Evaporation from saliva promotes the loss of heat from the blood.The rabbit- Endotherm The large ears of the rabbit-eared- eared- bandicoot provide a large surface area bandicoot to pass excess heat when it is burrowing during the heat of day and when it is active at dusk.
  38. 38. Rabbit-Eared Bandicoot
  39. 39. Magnetic Ectotherm Pack the walls of their mounds withtermites insulating wood pulp and align their mounds(Amitermes north-south to maximise exposure to the sunmeridionali in the mornings and the evenings when thes) air is cooler and to minimise exposure during heat of day.Bogong Ectotherm Able to avoid their bodies freezing bymoth supercooling their tissues. This process involves reducing the temperature of the body fluids below their usual point of freezing and as a result, ice crystals do not form and destroy the cells.
  40. 40. Identify the form(s) in which each of the followingis carried in mammalian blood:Carbon dioxideOxygenWaterSaltsLipidsNitrogenous wasteOther products of digestion
  41. 41. Substance From To Form Carried byOxygen Lungs Body Oxyhaemoglobi RBC’s cells nCarbon Body Lungs Hydrogen RBC’s and Dioxide cells carbonate plasma ions, bicarbonate ions
  42. 42. Water Digestive Body Water Plasma system cells molecules and body cellsSalts Digestive Body As ions in the Plasma system cells plasma and body cells
  43. 43. LipidsNitrogenous Liver and Kidneys Mostly as Plasma waste body urea, cells sometimes ammonia or uric acidOther Digestive Body As separate Plasma products syste cells molecules, of m and .e.g. digestion liver glucose, amino acids
  44. 44. Explain the adaptive advantage of haemoglobin Haemoglobin- Large protein molecules found in RBC’s Oxygen isn’t very soluble in water, which is why it’s carried in the haemoglobin It increases the oxygen carrying capacity of RBC’s by about four times. Mammals require a constant and large supply of oxygen to produce enough heat to maintain homeostasis.
  45. 45. Haemoglobin
  46. 46.  Supply can be adjusted to suit altitude Can bind to oxygen loosely-therefore release it quickly And advantage to be carried in and RBC. If just dissolved in plasma it would upset the osmotic balance of the blood. The development of RBC’s without a nucleus leaves more room for haemoglobin.
  47. 47. Compare the structures of arteries capillaries and veinsin relation to their function Artery Vein CapillarySketchDescription Thick, elastic, Bigger One cell thick in muscular walls in diameter than diameter ... arteries, has a larger but surface area their to volume muscular ratio. wall is much thinner.
  48. 48. Function Carry oxygen Carry Exchange rich blood deoxygenate materials from lungs to d blood back between the entire to the heart. blood and body body cells.Reason Blood is under They are not Large SA:V pressure and under as allows for needs to be much the easy pumped pressure and exchange of around to the only travel nutrients body. The one way. (needed by muscular They are cells and walls expand pushed up waste and contract through products) to push the valves. blood through.
  49. 49. Describe the main changes in the chemical composition of the blood as it moves around the body and identify tissues in which these changes occur The blood circulates through two systems in the body: the pulmonary system and the systemic system.The pulmonary system- Blood flows from the heart to the lungs and then back to the heart. Blood travels in the pulmonary artery from the right ventricle to the lungs where carbon dioxide is released into the alveoli of the lungs. This is then ultimately released out of the body. Oxygen is picked up from the alveoli and diffused into the red blood cells to then be taken back to the heart. So via the pulmonary system, carbon dioxide is decreased and oxygen levels increased.
  50. 50. The systemic system- Blood flows from the heart to the rest of the body, except the lungs, and then returns. The left ventricle pumps oxygenated blood to the rest of the body, and as this blood circulates in capillaries, oxygen is delivered to the cells and carbon dioxide is picked up. Other waste products, such as urea, are also picked up from the liver and transported in the blood to the kidneys. Blood flowing to the small intestines collects the products of digestion and transports them to the liver. Glucose is circulated in the blood stream to all cells in the body for respiration. Deoxygenated blood returns to the heart via the inferior and superior vena cava.
  51. 51. Outline the need for oxygen in living cells and explain why removal of carbon dioxide from cells is essentialOxygen- Needed for aerobic respiration to release energy A constant supply of oxygen is needed for the cells, otherwise they’ll dieCarbon dioxide A bi-product of respiration is carbon dioxide Increased carbon dioxide in blood stimulates the breathing centre in the brain, which is why we pant after exercise. We take in more oxygen than we give out. Carbon dioxide reacts with plasma (mostly water) to form carbonic acid (which is how it’s carried around the body). If this becomes too much, the carbonic acid upsets the pH level-making it more acidic, poisonous. However, we have special buffer systems to stop this.
  52. 52. Oxygen and Carbon Dioxide Molecules
  53. 53. Describe current theories about processesresponsible for the movement of materials through plants in xylem and phloem tissueXylem- The transpiration-cohesion-tension mechanism is currently the theory that accounts for the ascent of xylem sap. This sap is mainly pulled by transpiration rather than pushed by root pressure. Cohesion is the “sticking” together of water molecules so that they form a continuous stream of molecules extending from the leaves down to the roots. Water molecules also adhere to the cellulose molecules in the walls of the xylem. As water molecules are removed by transpiration in the leaf, the next molecule moves upwards to take its place, pulling the stream of molecules continuously along.
  54. 54. Xylem
  55. 55. Phloem- The pressure-flow mechanism is a model for phloem transport now widely accepted.The model has the following steps. Step 1: Sugar is loaded into the phloem tube from the sugar source, e.g. the leaf (active transport) Step 2: Water enters by osmosis due to a high solute concentration in the phloem tube. Water pressure is now raised at this end of the tube. Step 3: At the sugar sink, where sugar is taken to be used or stored, it leaves the phloem tube. Water follows the sugar, leaving by osmosis and thus the water pressure in the tube drops. The building up of pressure at the source end, and the reduction of pressure at the sink end, causes water to flow from source to sink. As sugar is dissolved in the water, it flows at the same rate as the water. Sieve tubes between phloem cells allow the movement of the phloem sap to continue relatively unimpeded.
  56. 56. Phloem
  57. 57. Perform a first-hand investigation to demonstrate the effect of dissolved carbon dioxide on the pH of waterChanging pHAim: to demonstrate the effect of dissolved carbon dioxide on the pH of water.Apparatus: Hydrochloric acid (0.1M) Calcium carbonate- powered Water Conical flask with side arm and connecting tubes Beaker Stopper Measuring cylinder Stop watch Universal indicator scales
  58. 58.  Method: set up apparatus as shown measure 30ml of hydrochloric acid and pour it into the conical flask Measure 40ml of water and place it in the beaker, add a few drops of universal indicator and record pH. Weigh 10g of calcium carbonate. Slowly pour into flask and quickly cover with stopper. Once the calcium carbonate is in contact with acid begin timing. Make sure the tube is placed in water. Record pH, measure at one minute intervals for five minutes Repeats steps 1-5 three times and record total average of results Repeat steps 1-5. Controlled reaction. Repeat step 7 three times and record total average of results.
  59. 59. Results: Experiment 2 Experiment 3 Experiment 1Time 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5 pH 6.5 6.5 6 5.5 5.5 6.5 6 5.5 5 5 6 6 5.5 6 5 Conclusion: When carbon dioxide dissolves in water, it produced carbonic acid, which causes a decrease in pH, from pH of 6.5 to 5.5 in distilled water.
  60. 60. Perform a first-hand investigation using the light microscopeand prepared slides to gather information to estimate the sizeof red and white blood cells and draw scaled diagrams of each
  61. 61. Analyse information from secondary sources to identify current technologies that allow measurement of oxygen saturation and carbon dioxide concentrations in blood and describe and explain the conditions under which these technologies are usedBiosensers- Made analysing blood gases quicker and more accurate. A biosensor is a device with a transducer and a bioreceptor, usually one that recognises specific biochemical molecules. The bioreceptor reacts specifically with the substance to be detected and the transducer, which may be electrochemical, optical or thermal, converts the biochemical signal into an electrical signal
  62. 62. Sensors A sensor is a device that translates a physical or chemical property into an electrical signal that can be measured. The key component is the transducer or signal-converting element that converts the poverty to be measured into a signal. Sensors usually use either optical or electrochemical technologies. Optical fibres are now replacing electrical wire for carrying signals in many sensors.
  63. 63.  Pulse oximeter (in hospitals) - a peg is attached to the finger of the patient where a light is transmitted through to the other side of the finger. A photo detector on the other side measures how much light has been transmitted through. The amount is directly proportional to the amount of oxygen in arterial blood.
  64. 64. Oximeter
  65. 65. Arterial Blood Gas Analysis Blood gas analysis, also called arterial blood gas (ABG) analysis, is a test which measures the amounts of oxygen and carbon dioxide in the blood, as well as the acidity (pH) of the blood. An ABG analysis evaluates how effectively the lungs are delivering oxygen to the blood and how efficiently they are eliminating carbon dioxide from it. The test also indicates how well the lungs and kidneys are interacting to maintain normal blood pH (acid-base balance). Done to assess respiratory disease and other conditions that may affect the lungs, and to manage patients receiving oxygen therapy (respiratory therapy). The acid-base component of the test provides information on kidney function. Blood gas analysis is performed on blood from an artery. It measures the partial pressures of oxygen and carbon dioxide in the blood, as well as oxygen content, oxygen saturation, bicarbonate content, and blood pH.
  66. 66. Arterial Blood Analysis Device
  67. 67.  Testing the partial pressure of oxygen is actually measuring how much oxygen the lungs are delivering to the blood. Carbon dioxide is released into the blood as a by-product of cell metabolism. The partial carbon dioxide pressure indicates how well the lungs are eliminating this carbon dioxide. A related value is the oxygen saturation, which compares the amount of oxygen actually combined with hemoglobin to the total amount of oxygen that the hemoglobin is capable of combining with.
  68. 68. Procedure- Oxygen Concentration In Blood Sample of blood taken Diffuses through a gas permeable membrane This produces an electrochemical reaction Which produces a current This current of proportional to oxygen concentration Carbon Dioxide Concentration In Blood Sample of blood is taken Diffused through a gas permeable membrane This changes the pH level in the solution The change in pH is proportional to carbon dioxide concentration.
  69. 69. Analyse information from secondary sources to identify the products extracted from donated blood and discuss the uses of these productsDonated blood- Broken down into: RBC’s- used to carry oxygen. Given to people with anaemia whose people don’t make enough RBC’s or people who’ve lost a lot of blood WBC’s- used to combat infection. Given to people with cancer of the blood e.g.- leukaemia. Used vary rarely- usually antibiotics are used Platelets-used for blood clotting. Given to people with cancer of the blood because they don’t make enough platelets Plasma-also used for blood clotting. Used to treat people with haemophilia. Used to adjust osmotic pressure of blood and to pull fluids out of tissues. Immunoglobins-infection fighting parts in plasma. Used to treat people with difficulty fighting infection. Whole blood-only given when >20% of blood is lost
  70. 70. Donated Blood Platelets and Plasma
  71. 71. Analyse and present information from secondary sources to report on progress in the production of artificial blood and use available evidence to propose reasons why such research is neededArtificial Blood- Need to be stored at room temp. and have a prolonged shelf life; 3-4 weeks World wide shortage of donor blood due to HIV/AIDS, Mad Cow Disease, new screening etc Need a safe and effective way to get a new blood source (considering there’s no donor blood anymore)
  72. 72. Used to: Increase plasma volume- artificial plasma expanders are used for severe burns- so the blood can clot and heal Carry oxygen and carbon dioxide- not other substitutes for any other nutrient yetTypes Perflurochemicals (PFC’s) Can dissolve about 50 times more oxygen than blood plasma Cheap and free of biological materials- no risk of infection To work must combine with other materials to mix with the blood stream-usually lipids. Haemoglobin- based oxygen carriers (HBOCs) Oxygen bonds chemically but only dissolves in PFC’s Not contained in a membrane-don’t require blood matching
  73. 73. Perflurochemicals
  74. 74. PROBLEMS Doesn’t stop haemoglobin from oxidising (doesn’t have the enzymes to stop it)- once oxidised it can’t carry oxygen Membrane protects the haemoglobin from degradation and toxic effects of haemoglobin Alters blood flow through smallest vessels Only stay in circulation for 20-30 hours, instead of RBC’s-100days If in an accident you’ll usually be given saline (sodium chloride- same concentration as blood and other tissues- 0.9%) OR dextrose- 4% glucose and 0.18% saline solution.
  75. 75. Choose equipment or resources to perform a first-hand investigation to gather first-hand data to drawtransverse and longitudinal sections of phloem and xylem tissue Xylem carries water and minerals upward from the root hairs (where the water comes from). Due to capillarity and the transpiration stream. They are dead tissues and narrow. Phloem carries minerals produced by photosynthesis; mainly sugar, up and down the plant. Symplastic Loading- materials travel in the cytoplasm from the mesophyll cells to the sieve element (the phloem) through plasmodesmata. This means a lot of plasmodesmata are required.
  76. 76.  Apoplastic Loading- nutrients travel through the cell walls until they get to the sieve element. They then cross the cell membrane into the phloem. The sieve element becomes loaded with sugars (nutrients) and dumps them into a sink cell. This keeps pressure of the phloem constant.
  77. 77. Explain why the concentration of water in cells should be maintained within a narrow range for optimal function. Water concentration in cells is critical for most living organisms. It must remain constant as slight changes may lead to cell death. This is because: Water is essential for life. Water is the solvent for all the metabolic reactions in living cells. It takes part directly in many of them such as photosynthesis and is formed as a product in many others including respiration. Living cells function best in an isotonic environment (one in which the solute concentration is the same both inside and outside the cell). They are very sensitive to changes in solute concentration and as consequence may lose or take in large amounts of water by osmosis. Changes in concentration of water in the cell will affect the concentration of dissolve substances, which in turn can affect the metabolic function
  78. 78. Explain why the removal of wastes is essential for continued metabolic activity. Wastes products are constantly being formed as a result of metabolic processes that occur in cells. However, the removals of these wastes are essential because: Some of the wastes build up as toxins and could poison the cells. For example:  Carbon dioxide  Nitrogenous wastes If allowed to accumulate in cells and tissues, these wastes could disrupt or slow down metabolic reaction rates
  79. 79. Different animals excrete different wastes products Aquatic animals, fish and invertebrates mostly excrete ammonia. Ammonia is toxic, but can be released continuously and directly into the water and is quickly dispersed Terrestrial animals excrete nitrogenous waste as either urea or uric acid. This is because terrestrial animals need to conserve water by converting ammonia into less toxic forms and excrete it periodically. Urea is soluble and is released in urine while uric acid is almost insoluble and non-toxic.
  80. 80. Identify the role of the kidney in the excretory system of fish and mammals. Kidney is an organ of filtration, reabsorption and secretion. The primary role of the kidneys is osmoregulation, the regulation of the water and salt concentrations in the body. The kidney forms urine by removing wastes such as nitrogenous wastes, salts, other unwanted metabolic products and excess water, from the blood. The kidney maintains the balance of salts and water in the body, and so has a vital role in homeostasis. NB: The structural and functional unit of the kidney is the nephron. There are approximately 1 million nephrons in each human kidney. Each nephron is made up of glomerulus and tubules.
  81. 81. Nephron Process
  82. 82. Explain why the processes of diffusion and osmosisare inadequate in removing dissolved nitrogenous wastes in some organisms. The processes of diffusion and osmosis are inadequate for removal of wastes because: Diffusion is too slow and non-selective of solutes Diffusion would mean all salts would be eliminated along with glucose and vitamins; whereas the body needs to retain some salts and nutrients Osmosis would mean that wastes would stay in the body and that water would leave
  83. 83. Osmosis
  84. 84. Distinguish between active and passive transport and relate these to processes occurring in the mammalian kidney. In the kidneys both forms of transport are used in regulating the body fluid composition. Passive transport requires no energy. Passive transport occurs in filtration and in the osmosis of water back into the blood. Active transport requires energy from metabolism (ATP). Active transport occurs in the secretion of substances into the nephron, the active transport of nutrients back into the blood, and the selective reabsorption of salts required by the body. These processes require energy, as they would have to go against the concentration gradient.
  85. 85. Explain how the processes of filtration and reabsorption in the mammalian nephron regulate fluid composition. Filtration and reabsorption occurs in the nephron. Filtration involves the removal of substances from blood if they are small enough to be forced through the glomerulus and into the Bowman’s capsule. The glomerulus acts like an ultra filter and particles that are too large such as proteins cannot pass through the Bowman’s capsule. Filtered blood then moves along the tubules. Useful substances such as water, glucose, amino acids, vitamins, hormones and inorganic salts are reabsorbed through diffusion and osmosis. Hence, the processes of filtration and reabsorption regulate body fluid composition as it perform the complex balancing of retaining essential substances and removing toxic wastes from blood to maintain homeostasis.
  86. 86. Outline the role of the hormones, aldosterone and ADH (anti-diuretic hormone) in the regulation of water and salts levels in blood. Adolsterone is a steroid hormone produced by the adrenal cortex of the kidney. Its role is to maintain a balance of water and salts in the body. It stimulates the nephron to increase the concentration of sodium ions leading to a decrease in reabsorption of potassium ions and more water diffusing into blood at the nephron. This causes a rise in blood pressure and volume. Anti-diuretic Hormone (ADH) is a hormone produced by the hypothalamus and stored in the pituitary gland that stimulates the nephrons to absorb more water. This acts to decrease urine volume.
  87. 87. Antidiuretic Hormone Action
  88. 88. Define enantiostasis as the maintenance ofmetabolic and physiological functions in response to variations in the environment and discuss its importance to estuarine organisms in maintaining appropriate salt concentrations. Enantiostasis is the maintenance of metabolic and physiological functions in response to variations in the environment. To estuarine organisms the maintenance of salt concentrations is important. Many of the organisms cannot control salt and water levels, instead they exhibit enantiostasis in order to survive the daily change in salinity. Ways in which some estuarine organisms function to overcome daily change in salinity:
  89. 89.  Fast-swimming organisms can move away from area with high salinity Molluscs can close their shells Bottom dwellers burrow or dig deep into mud or sand Halophytes tolerates changes in salinity by having a special mechanism to control their level of slat Saltbushes have special salt excretion glands on their leaves Some mangroves excrete salt from special glands in their leaves
  90. 90. Mangroves
  91. 91. Describe adaptations of a range of terrestrial Australian plants that assist in minimizing water loss Some adaptations to limit water loss that Australian plants exhibit include: Hard or thick waxy cuticles on leaves, such as eucalypts Hairy leaves, stems and even flowers to restrict air flow and evaporation, such as alpine groundsel Leaves that droop or roll to reduce the exposure of stomates, such as spinifex A tough, woody structure that prevents plants wilting even when they lose water, such as alpine groundsel Small leaves, such as saltbushes Leaves with a reduced number of stomates Widely spreading or deep root systems to obtain more water, such as mulga
  92. 92. Perform a first-hand investigation of the structure of a mammalian kidney dissection, use a model or visual resource and identify regions involved in the excretion of waste products.
  93. 93. Gather, process and analyse information fromsecondary sources to compare the process of renal dialysis with the function of the kidney.
  94. 94. Kidney function Renal dialysisA natural body process An artificial process replacing damage kidneyPerformed by two fist-sized organs Performed by a large machine attached to a variety of computer and other equipmentRemoves wastes continuously Performed repeatedly under hospital conditions (two or three times each week, for several hours each time)Varies output automatically, Concentrations of substances in depending on concentrations of blood and dialysis fluid are wastes in blood monitored by computers so that most wastes are removed during treatmentWastes may be removed by both Wastes removed by diffusion diffusion and active transport
  95. 95. Present information to outline the general use ofhormone replacement therapy in people who cannot secrete adolsterone. Aldosterone is used to regulate water and salt reabsorption. When aldosterone cannot be secreted, the excretory system will not be as efficient. The person cannot maintain homeostasis and become severely dehydrated. The hormone replacement is taken on a regular basis, to maintain balance of salts. The main artificial substitute for adolsterone is called fludrocortisone. Appropriate hormone replacement therapy can enable patients to manage symptoms such as fluid retention and high blood pressure and lead normal lives.
  96. 96. Analyse information from secondary source to compare and explain the differences in urineconcentration of terrestrial mammals, marine fish and freshwater fish.
  97. 97. Type of Urine components and Explanation animal concentrationTerrestrial Concentrated urine, Excess salts and other wastes are mammal usually composed of excreted dissolved in water. Water(e.g. bilby) urea, salts, other needs to be conserves, urine wastes and water. produced is concentrated. Nitrogenous wastes present as urea - it is less toxic than ammonia and can be present in higher concentrationFreshwater Large quantities of very Freshwater fish absorb large volumes of fish dilute urine, usually water through gills and mouth thus(e.g. native composed of much water must be excreted. bass) ammonia, small Ammonia is suitable - sufficient amounts of salts and water to dilute it. Salts - low large amount of water concentration in fresh water, therefore fish take up salts from water as replacement.
  98. 98. Marine fish Small quantities of Marine fish constantly lose water - high(e.g. concentrated urine, salt environment. Excrete little water inwhiting) usually composed of concentrated urine containing high trimethylamine oxide, levels of non-toxic trimethylamine oxide other wastes and small and salts. volumes of water
  99. 99. Use available evidence to explain the relationship between the conservation of water and the production and excretion of concentratednitrogenous wastes in a range of Australian insects and terrestrial mammals. Type of nitrogenous wastes (uric acid or urea) and its high concentration enable these organisms to reduce the amount of water they lose to remove wastes. This helps them to conserve water in harsh and dry environments.
  100. 100. Process and analyse information from secondary sources and use available evidence to discuss processes used by different plants for salt regulation in saline environments. Mangrove: Shrubby tree that grows in estuaries Its roots have a layer of cells that actively restrict the movement of salt into xylem vessels Able to excrete salt through the underside of its leaves. Salt crystals accumulate on leaves and so salt is lost when older leaves fall from plant Saltbush: Tolerate salinity levels that kill most other plants Excrete large amount of salt through their leaves In general plants removed salt for regulation by: Salt can be redirected towards drying leaves, so when drop off the plants, the salt is removed Salt excretion glands actively excrete salt by allowing it to crystallize and be blown or washed away Osmotic adjustment
  101. 101. Perform a first-hand investigation to gatherinformation about structures in plants that assist in the conservation of water.

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