2. Lesson OutLine RESPIRATION Aerobic Vs Anaerobic Respiration Anatomy of the Respiratory System Smoking and Lung Diseases Physiology of the Respiratory System Mechanism of Breathing Aerobic Respiration Anaerobic Respiration
3. Learning Objectives By the end of the lesson, you should be able to: Define aerobic respiration as the release of a relatively large amount of energy by the breakdown of food substances in the presence of oxygen State the equation (in words and symbols) for aerobic respiration Define anaerobic respiration as the release of a relatively small amount of energy by the breakdown of food substances in the absence of oxygen State the equation (in words only) for anaerobic respiration in humans
4. Energy Makes the World Goes Round Everything in the world works only because they could use energy. and Life is no exception…
5. Burning Food… … Early Earth is a tough neighbourhood Earth was borne out of the solar nebula without oxygen. Why is this so? If there was no oxygen, how did life begin?
6. A Thirst for Energy -An Ancient Battle Life didn’t really need oxygen, but there is one thing that all life needs… and that is Energy. The battle for energy is an ancient one, and even today, people war with one another for sources of energy such as fossil fuel. Sulphur Bacteria Methanogens
9. How does body convert energy stored in food energy for body use?
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11. Respiration is a characteristic of life since all living things require energy for essential activities2 Types of : Aerobic and Anaerobic respiration
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16. Carbon dioxide and water are released as waste products.Anaerobic Respiration is the breakdown of food molecules in the absence of oxygen. Anaerobic respiration releases less energy than aerobic respiration.
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18. Aerobic respiration generate heat, which is circulated around the body to maintain a constant optimum body temperature
27. Hence only a small amount of energy is released in the processGlucose Carbon dioxide + ethanol + little energy Glucose Lactic acid + little energy
33. Production of lactic acid PG 196 In Muscles During strenuous exercise, the breathing rate and heartbeat will be increased so that oxygen can be brought faster to muscles There is a limit to rate of breathing and heartbeat Extra energy for strenuous exercise is thus produced by anaerobic respiration in muscles
34. What happens when you need more energy but not enough oxygen? PG 196
35. Anaerobic Respiration in the Muscles Vigorous muscle movement increase rate of aerobic respiration (oxidation of glucose) to release more energy. Prolonged muscular contraction 2. Insufficient oxygen available leads to muscle cells undergoing anaerobic respirationto release even more energy. 3. Lactic acid accumulates in muscles causing fatigue, muscle pain, cramps. 4. Muscle cells incur oxygen debt. PG 196
36. PG 196-197 During recovery… Breathing rate continues to be fast. Provides oxygen to repay oxygen debt. Oxygen can break down lactic acid: to produce energy Convert lactic acid back into glucose Oxygen debt is repaid when lactic acid is used up. “Repaying” oxygen debt
37. Oxygen debt PG 196-197 The amount of oxygen needed to dispose of the lactic acid is called oxygen debt The time taken to remove all the lactic acid is called the recovery period
38. PG 196 Energy needed for vigorous exercise Aerobic respiration Glucose + oxygen Carbon dioxide + water + energy Anaerobic respiration Glucose + Oxygen Lactic acid + little energy Total amount of energy needed for vigorous muscular contractions
39. Investigation 10.3 (page 199) 3 To allow oxygen to diffuse in and carbon dioxide to diffuse out of the flask. 5 The reading should be higher than room temperature for flask A. Germinating seeds release heat during respiration. 6 Advantages are: a) fewer seeds need to be used. b) the thermometers need not be inserted too deeply into the flask so that they can be read more easily.
40. Test Yourself (Page 200) Test Yourself! (page 200) 1(a) The solution would turn yellow. The snail would respire and give out carbon dioxide. Carbon dioxide would dissolve in the water to form carbonic acid. (b) The solution would turn purple. The green plant would photo synthesise and remove carbon dioxide from the solution. (c) Any carbon dioxide released by the snail is used up by the plant for photosynthesis. The rate of photosynthesis = the rate of respiration in both organisms. No. It serves as a control. 23(a) Rate of oxygen uptake (b) To absorb carbon dioxide (c) To the left (d) Rate of oxygen uptake = (100 X ( X 12)/2) mm2/minute 4 Refer to Investigation 10.2 (page 199).
41. 2(a) The set-up would be similar to that in question 3, if the boiling tube in question 3 were replaced by the conical flask containing germinating bean seeds. The tube of sodium hydroxide could be suspended within the flask. (b) The sodium hydroxide would absorb any carbon dioxide produced as a result of respiration, therefore any change in the volume of air inside the flask would be due to the uptake of oxygen by the seeds. As oxygen is taken up by the seeds, the droplet of coloured water would move along the capillary tube. The position of the coloured droplet would indicate the volume of oxygen taken in. Readings would be taken at suitable time intervals, e.g. 5 s, 10 s, 15 s and then averaged to find out the rate of oxygen uptake by the germinating seeds. (c) Changes in the temperature of the surroundings may affect the rate of oxygen uptake by the germinating bean seeds. The temperature of the surroundings should be kept constant (set-up should be placed in a warm environment as the seeds are germinating).
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43. Learning Objectives By the end of the lesson, you should be able to: identify on diagrams and name the larynx, trachea, bronchi, bronchioles, alveoli and associated capillaries state the characteristics of, and describe the role of, the exchange surface of the alveoli in gaseous exchange describe the role of cilia, diaphragm, ribs and intercostal muscles in breathing
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45. As such all respiratory surfaces must be moist.
46. This is no problem for an aquatic animal such as a fish.
56. Nasal Passages (Nasal cavity) Lined with moist mucus membrane. Advantages of breathing through nose: Hairsand moist mucous membrane lining alls of external nostrils filter air, trap dust and foreign particles Blood capillaries and mucuswarm and moisten air respectively before entry into lungs. Sensory cells(small receptor cells) in mucous membrane may detect harmful chemicals in the air (sense of smell)
57. Path of Air Through the Respiratory System atmosphere external nostril nasal passages Pharynx (throat) nasal passages pharynx external nostril Located behind the mouth cavity, air passes through it on the way to glottis
75. PG 205 What causes air movement into the lungs? Vertebral column sternum ribcage lung Internal intercostal muscle External intercostal muscle Diaphragm
76. The workings of the intercoastal muscles and the diaphragm changes the volume of the thoracic cavity PG 205 Mechanism of Breathing
77. PG 206 Mechanism of Breathing - Inhalation When you breathe in or inhale, the following events take place: Movement of rib cage during inhalation Front view Side view TB PG vertebral column sternum rib rib cage
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85. PG 206 Mechanism of Breathing - Inhalation What causes air movement into the lungs? Diaphragm contracts External Intercostal Muscles contract Internal Intercostal Muscles Relax Rib cage and sternum move upwards and forward Volume of thoracic cavity increase Pressure of thoracic cavity decrease Lungs expand and air pressure in lungs lower than atmospheric air pressure Air rush in from atmosphere to lungs Biomechanical Physical Parameters
86. PG 206 Mechanism of Breathing - Inhalation Demonstration of Changes in Physical Parameters Volume in thoracic cavity increase Pressure in thoracic cavity decrease Pressure in Lungs > Pressure in thoracic cavity Lungs expand Pressure in lungs drop Atmospheric pressure > Pressure in lungs Air rushes in
87. PG 207 Mechanism of Breathing -Exhalation When you breathe out or exhale, the following events take place: Movement of rib cage during expiration Side view Front view vertebral column sternum rib rib cage
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94. 6 August 2011 Mechanism of Breathing What happens to your intercostal muscles when you are breathing?
95. PG 207 Mechanism of Breathing What happens to your intercostal muscles when you are breathing? R When you inhale, you… Relax your Internal intercostal muscles and Contract your External intercostal muscles I C E
96. PG 207 Mechanism of Breathing What happens to your intercostal muscles when you are breathing? R When you inhale, you… Relax your Internal intercostal muscles and Contract your External intercostal muscles I C E When you exhale, your… External intercostal muscles Relax and your Internal intercostal muscles Contract E R I C
97. Mechanism of Breathing - Exhalation Demonstration of Changes in Physical Parameters Volume in thoracic cavity decrease Pressure in thoracic cavity increase Pressure in Lungs < Pressure in thoracic cavity Lungs contract Pressure in lungs drop Atmospheric pressure < Pressure in lungs Air rushes out
99. Learning Objectives By the end of the lesson, you should be able to: State the characteristics and role of alveoli in gaseous exchange Describe the removal of carbon dioxide from the lungs, including the function of carbonic anhydrase.
101. Mechanics of Breathing - Expiration What causes air movement out of the lungs? Diaphragm ________________ . External Intercostal Muscles _______________ . Internal Intercostal Muscles _______________ . Rib cage and sternum move _____________ and _____________ . Volume of thoracic cavity ______________ . Pressure of thoracic cavity ____________ . Lungs ___________ and air pressure in lungs ___________ than atmospheric air pressure Air flows from ___________ to _______________ . Biomechanical relaxes relaxes contracts downwards inwards Physical Parameters decreases increases collapse higher lungs atmosphere
105. Pg 208 Gaseous Exchange- Oxygen How is oxygen taken into the blood capillaries during inspiration? PART 1 – Diffusion Atmospheric air higherconcentration of oxygen. Deoxygenated blood arriving at the alveoli from the pulmonary artery a lower concentration of oxygen. This sets up a concentration gradient for oxygen in the alveolar cavity and the blood in the capillaries.
106. Gaseous Exchange- Oxygen Pg 208 How is oxygen taken into the blood capillaries during inspiration? PART 2 – Structure Oxygen thus diffusesfrom the alveolar cavity into the blood capillaries, By dissolving in the thin film of moisture along the alveolar walls. And crossing the one-cell thick membrane of the alveolar wall and blood capillary.
107. Gaseous Exchange- Oxygen Transport in body Pg 208 How is oxygen taken into the blood capillaries during inspiration? PART 3 – Association with Haemoglobin Haemoglobin in red blood cells bind reversibly with oxygen: Oxygen concentration higher in lungs. Hb binds O2. Hb + O2HbO(oxyhaemoglobin)
108. Pg 209 Gaseous Exchange- Carbon Dioxide Transport in body In Actively Respiring Tissues & Blood plasma CO2 diffuses into blood capillaries from actively respiring tissues. CO2 dissolved in blood plasma then combines with water to form carbonic acid: This reaction is catalysed by an enzyme known as carbonic anhydrase. Carbonic acid then dissociates further into hydrogen carbonate anions in blood plasma MOST OF THE CO2 is carried as hydrogencarbonate ions in blood plasma CO2 + H2O H2CO3 Carbonic anhydrase(from RBC) H2CO3H+ + HCO3-
109. Gaseous Exchange- Carbon Dioxide In Lung Tissues Hydrogen carbonate anions in blood recombines with H+ to form carbonic acid. Carbonic acid converted back to CO2 and H2O. CO2 diffuses across capillary and alveolar walls into alveolar cavity. Expelled out of lungs by expiration.
111. Oxygen and carbon dioxide concentration gradient between alveolar air and blood are maintained by:-A continuous flow of blood through blood capillaries- Breathing air in and out of alveoli
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114. Test Yourself (Page 213) INCREASE Rate of diffusion of oxygen from the lungs into the blood and of carbon dioxide out of blood into the lungs. This result in a lower concentration of carbon dioxide in blood or in alveolar air, which lessen the stimulus to breathe. (b) Increasing the carbon dioxide in the air to 8%, even with a 71% increase above normal in oxygen concentration, still increases the rate of breathing greatly. This shows that the stimulus to breathing is carbon dioxide.
115. Learning Objectives By the end of the lesson, you should be able to: identify on diagrams and name the larynx, trachea, bronchi, bronchioles, alveoli and associated capillaries state the characteristics of, and describe the role of, the exchange surface of the alveoli in gaseous exchange describe the role of cilia, diaphragm, ribs and intercostal muscles in breathing
116. Learning Objectives By the end of the lesson, you should be able to: describe the effects of constituents of tobacco smoke and its major toxic components – nicotine, tar and carbon monoxide, on human health describe how smoking results in respiratory diseases such as emphysema, bronchitis, and lung cancer
142. The agent causes the rapid abnormal growth of cells in bronchial tube wall
143. If growth is unchecked or destroyed, cancer may spread to neighbouring cells and organs
144. Growth also blocks the bronchial tube so that breathing becomes more and more difficult
145. Life expectancy is usually decreased by smoking, especially if smoking was started at a young age
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151. Photosynthesis rate is higher than respiration rate in bright sunlight oxygen in excess diffuse out through stomata
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Notes de l'éditeur
- Different organisms have several alternative ways of getting energy from food, without using oxygen, but all are less efficient than aerobic respiration, and do not break food down fully into the simplest substances.Some organisms they live in places where there is very little oxygen such as these muddy soils. So how do they get energy? To survive in this habitat, the microbes have to adapt by using anaerobic respiration to provide them with energy. Although anaerobic respiration is a primitive and inefficient form of energy release, deriving from the period when oxygen was missing from the atmosphere, it can also be seen as an adaptation. To survive in some habitats, such as the muddy bottom of a polluted river, an organism must be to a large extent independent of oxygen; such habitats are said to be anoxic. In the thick mud at the bottom of this pond, there is very little oxygen. Some bacteris live in this mud. They break down glucose without using osygen. So they respire anaerobically. During anaerobic respiration, less energy is released than aerobic, because the glucose molecule is only partly broken down. Co2 is released, alcohol may be formed as a waste product. And we call this fermentation to make alcoholic drinks.
What is this? This is used to make your wine and bread. Yeast are a type of fungi. Yeasts are characterized by a wide dispersion of natural habitats. Common on plant leaves and flowers, soil and salt water. Yeasts are also found on the skin surfaces and in the intestinal tracts of warm-blooded animals, where they may live symbiotically or as parasites.Use of anaerobic respiration in industryIn plants, yeasts, and bacteria, anaerobic respiration results in the production of alcohol and carbon dioxide, a process that is exploited by both the brewing and the baking industries (see fermentation).Many industries have made use of the waste pdts from yeast’s ananerobicresoiration(c02 and ethanol) to make useful pdts. Can you make a guess to what they are?
If u look closely at many fruits e.g grapes, there are yeast living on their surface. And we know yeast respire anerobically and grapes is made up of sugar. So if you were to store these fruits with yeast on it for a while, u will taste alcohol. Becos the yeast can undergo anaerobic respiration and breakdown the sugar to give alcohol. Another term for anaerobic respiration is fermentation, or alcoholic fermentation, since it produces alcohol. So what brewery industry does is they add yeast to food such as rice, barley, corn whereby yeast will ferment the sugar in these food to produce alcoholic beverages such as wine and beer.
in the baking industry the bakers also use yeast to make bread. And the yeast used is called baker’s yeast. Bakers are more interested in the carbon dioxide released rather than the alcohol.Yeast is added to dough, the yeast starts to feed on he sugar in the flour, fermenting the sugar to give co2, which expand and cause dough to be raised. So when its put in the oven, the heat will kill the yeast and evaporate the alcohol, leaving behind light bread with light, fluffy texture. Some of the bread u eat is made with yeast.
Besides some bacteria and yeast which respire anaerobically, larger organisms like humans too! Who ran for last sat’s sports day? How did you feel when you were running during the race? Were u breathing very hard? After the race, were you panting?During an intensive exercise such as sprinting, initially, your body undergo aerobic respiration to provide energy to power the run. But if you are exercising so intensely, you may reach a point where you cannot take in oxygen any faster. You are making energy by aerobic respiration as fast as you can, but your body still needs more energy. So where does your body get more energy from to sustain your run? At this point, some of the glucose will be broken down anaerobically, due to insufficient oxygen, to provide a bit of extra energy.And in this case, for human, the waste product is not alcohol; bit lactic acid. So after your run, u will usually see the runners, breathing heavily and catching their breath even though they have stopped running. That’s because, during the run, lactic acid has build up in the leg muscle, so the runners need to breath fast and gard to get extra energy to break down the accumulated lactic acid to pay back the oxygen debt built up during the sprint.
