- 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.
Respiration 3 e_part 1
Respiration<br />The Breath of Life<br />
Lesson OutLine<br />RESPIRATION<br />Aerobic Vs Anaerobic Respiration<br />Anatomy of the Respiratory System<br />Smoking and Lung Diseases<br />Physiology of the Respiratory System<br />Mechanism of Breathing<br />Aerobic Respiration<br />Anaerobic Respiration<br />
Learning Objectives<br />By the end of the lesson, you should be able to:<br />Define aerobic respiration as the release of a relatively large amount of energy by the breakdown of food substances in the presence of oxygen<br />State the equation (in words and symbols) for aerobic respiration<br />Define anaerobic respiration as the release of a relatively small amount of energy by the breakdown of food substances in the absence of oxygen<br />State the equation (in words only) for anaerobic respiration in humans<br />
Energy Makes the World Goes Round<br />Everything in the world works only because they could use energy.<br />and Life is no exception…<br />
Burning Food… …<br />Early Earth is a tough neighbourhood<br />Earth was borne out of the solar nebula without oxygen.<br />Why is this so?<br />If there was no oxygen, how did life begin?<br />
A Thirst for Energy -An Ancient Battle<br />Life didn’t really need oxygen, but there is one thing that all life needs… and that is Energy.<br />The battle for energy is an ancient one, and even today, people war with one another for sources of energy such as fossil fuel.<br />Sulphur Bacteria<br />Methanogens<br />
Aerobic and Anaerobic Respiration<br /><ul><li>Those who uses oxygen to oxidize food:
Those who do not use oxygen to oxidize food:</li></ul>Aerobic Respiration<br /><ul><li>is the oxidation of glucose in the presence of oxygen with the release of a large amount of energy.
Carbon dioxide and water are released as waste products.</li></ul>Anaerobic Respiration<br />is the breakdown of food molecules in the absence of oxygen. Anaerobic respiration releases less energy than aerobic respiration.<br />
Aerobic Respiration<br />Glucose + oxygen carbon dioxide + water + release large amount of energy <br /><ul><li>Catalysed by enzymes
Aerobic respiration generate heat, which is circulated around the body to maintain a constant optimum body temperature
Many processes in living organisms require energy:
Transmission of nerve impulses</li></li></ul><li>Anaerobic respiration<br />Pg 195-196<br />Definition:<br />Anaerobic respiration is the release of a relatively small amount of energy by the breakdown of food substances in absence of oxygen<br /><ul><li>Glucose is only partially broken down.
The ethanol/lactic acid produced still contain much energy.
Hence only a small amount of energy is released in the process</li></ul>Glucose Carbon dioxide + ethanol + little energy<br />Glucose Lactic acid + little energy<br />
Some microbes living in the mud… low oxygen level …<br />Respire ananerobically!<br />
Production of lactic acid<br />PG 196<br />In Muscles<br />During strenuous exercise, the breathing rate and heartbeat will be increased so that oxygen can be brought faster to muscles<br />There is a limit to rate of breathing and heartbeat<br />Extra energy for strenuous exercise is thus produced by anaerobic respiration in muscles<br />
What happens when you need more energy but not enough oxygen?<br />PG 196<br />
Anaerobic Respiration in the Muscles<br />Vigorous muscle movement increase rate of aerobic respiration (oxidation of glucose) to release more energy.<br />Prolonged muscular contraction<br />2. Insufficient oxygen available leads to muscle cells undergoing anaerobic respirationto release even more energy.<br />3. Lactic acid accumulates in muscles causing fatigue, muscle pain, cramps.<br />4. Muscle cells incur oxygen debt.<br />PG 196<br />
PG 196-197<br />During recovery…<br />Breathing rate continues to be fast.<br />Provides oxygen to repay oxygen debt.<br />Oxygen can break down lactic acid:<br />to produce energy<br />Convert lactic acid back into glucose<br />Oxygen debt is repaid when lactic acid is used up.<br />“Repaying” oxygen debt<br />
Oxygen debt<br />PG 196-197<br />The amount of oxygen needed to dispose of the lactic acid is called oxygen debt<br />The time taken to remove all the lactic acid is called the recovery period<br />
PG 196<br />Energy needed for vigorous exercise<br />Aerobic respiration <br />Glucose + oxygen Carbon dioxide + water + energy<br />Anaerobic respiration <br /> Glucose + Oxygen Lactic acid + little energy<br />Total amount of energy needed for vigorous muscular contractions<br />
Investigation 10.3 (page 199)<br />3 To allow oxygen to diffuse in and carbon dioxide to diffuse out of the flask.<br />5 The reading should be higher than room temperature for flask A. Germinating seeds release heat during respiration.<br />6 Advantages are:<br /> a) fewer seeds need to be used.<br /> b) the thermometers need not be inserted too deeply into the flask so that they can be read more easily.<br />
Test Yourself (Page 200)<br />Test Yourself! (page 200)<br />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.<br />(b) The solution would turn purple. The green plant would photo synthesise and remove carbon dioxide from the solution.<br />(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.<br />No. It serves as a control.<br />23(a) Rate of oxygen uptake<br /> (b) To absorb carbon dioxide<br /> (c) To the left<br /> (d) Rate of oxygen uptake = (100 X ( X 12)/2) mm2/minute<br />4 Refer to Investigation 10.2 (page 199).<br />
2(a) The set-up would be similar to that in question 3, if the boiling tube in <br /> question 3 were replaced by the conical flask containing germinating bean seeds. The tube of sodium hydroxide could be suspended within the flask.<br />(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.<br />(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). <br />
How do organisms obtain oxygen for aerobic respiration?<br /><ul><li>Gaseous exchange: Exchange of gases between an organism and the environment</li></ul>How do human carry out gaseous exchange?<br />
Learning Objectives<br />By the end of the lesson, you should be able to:<br />identify on diagrams and name the larynx, trachea, bronchi, bronchioles, alveoli and associated capillaries<br />state the characteristics of, and describe the role of, the exchange surface of the alveoli in gaseous exchange<br />describe the role of cilia, diaphragm, ribs and intercostal muscles in breathing<br />
Adaptations to Land Living<br /><ul><li>Oxygen must be dissolved before it can be absorbed.
As such all respiratory surfaces must be moist.
This is no problem for an aquatic animal such as a fish.
What about terrestrial animals?</li></li></ul><li>Respiratory surfaces<br />The surface through which respiratory gases are exchanged between the organism’s internal and external environment<br />The actual design of the surface depends on factors like habitat, size and activity of organism<br />E.g. Lungs –mammals, birds, reptiles, amphibians<br /> Gills –Fish, amphibians<br />Tracheoles – Arthropods<br /> Leaf cells – Plants<br /> Body covering- small animals (amoeba, earthworm)<br />
Adaptations to Land Living<br /><ul><li>As the first vertebrate animal venture onto land, obtaining oxygen becomes a gargantuan task.
There is little moisture for the respiratory surface to function properly.</li></li></ul><li>Respiratory Surfaces<br /><ul><li>Moist respiratory surface (air sacs are located in body cavity)
Allow animal to dissolve oxygen from the air directly into the moist respiratory surfaces.</li></li></ul><li>Characteristics of Respiratory Surfaces<br />Moist surface for oxygen to dissolve<br />Large surface area to volume ratio for gasesous exchange<br />Thin-walled ensure a faster rate of diffusion/exchange of gases<br />Close association with circulatory system: <br />Richly supplied with blood capillaries (continuous blood flow maintains steep diffusion gradient) <br /> Rate of diffusion of gases across respiratory surfaces is increased <br />
Nasal Passages (Nasal cavity)<br />Lined with moist mucus membrane.<br />Advantages of breathing through nose:<br />Hairsand moist mucous membrane lining alls of external nostrils filter air, trap dust and foreign particles<br />Blood capillaries and mucuswarm and moisten air respectively before entry into lungs.<br />Sensory cells(small receptor cells) in mucous membrane may detect harmful chemicals in the air (sense of smell)<br />
Path of Air Through the Respiratory System<br />atmosphere <br />external nostril <br />nasal passages<br />Pharynx (throat)<br />nasal passages<br />pharynx<br />external nostril<br /> Located behind the mouth cavity, air passes through it on the way to glottis<br />
Is the voicebox with vocal chords stretched across it</li></li></ul><li>9 August 2011<br />Path of Air Through the Respiratory System<br />atmosphere <br />external nostril <br />nasal passages<br />pharynx<br />larynx<br />Trachea (Windpipe)<br />nasal passages<br />pharynx<br />external nostril<br />larynx<br />trachea<br /><ul><li>A long tube supported by C-shaped rings of cartilage to keep it open.
Inner wall lined with cilia and mucous membrane
Cilia beat rhythmically and move particles away from lungs</li></li></ul><li>Trachea or Windpipe<br />
Trachea<br />Contains C-shaped cartilage<br />Keeps airways opened and prevent it from collapsing<br />