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34 Cards in this Set
- Front
- Back
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What is respiration? |
It is the breakdown of food substances with the release of energy in living cells |
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What is aerobic respiration? |
Aerobic Respiration is the breakdown of food substances in the presence of oxygen with the release of large amounts of energy |
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What is the waste product of aerobic respiration? |
Carbon dioxide and water |
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What is equation for aerobic respiration? |
glucose + oxygen -------> carbon dioxide + water + energy C6H12O6 + O2 ------> CO2 + H20 + energy |
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What is anaerobic respiration? |
Anaerobic respiration is the breakdown of food substances (glucose) in the absence of oxygen |
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What is the difference between anaerobic and aerobic respiration? |
Anaerobic respiration releases less energy compared to aerobic respiration |
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What is the equation for anaerobic respiration in yeast? |
Glucose ----> ethanol + carbon dioxide + small amt of energy C6H12O6 -----> 2 C6H6OH + 2CO2 + small amt of energy |
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What happens during strenuous exercise? |
1) During vigorous muscle contractions, the muscle cells respire aerobically 2) However, during strenuous exercise, there may not be sufficient oxygen supplied to the muscle cells to sustain aerobic respiration as there is a limit to the rate of breathing an heart rate 3) Hence, muscle cells respire anaerobically for short durations in order to meet the energy demands of the activity. 4) The extra energy released by anaerobic respiration supplements the energy released by aerobic respiration to allow continuous musclecontraction 5) When anaerobic respiration occurs, there is a buildup of lactic acid in the muscle cells. 6) The muscles are incur an oxygen debt and lactic acid build up causes fatigue and muscular pains |
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What happens during the recovery period after exercise and how is the oxygen debt repaid? |
1) During the recovery period, the breathing rate continues to be fast for some time to take in more oxygen to repay the oxygen debt. 2) Lactic acid is removed from the muscles and transported to the liver. 3) In the liver, oxygen is also used to oxidized some of the lactic acid to release energy. 4) This energy is used to convert the remaininglactic acid back into glucose. 5) When all the lactic acid has been converted to glucose, the oxygen debt is repaid. |
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How do we know that aerobic respiration is taking place? |
During aerobic respiration, an organism take sin oxygen and gives off carbon dioxide and heat energy |
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How do we know that anaerobic respiration in yeast is taking place? |
We can say that it is respiring anaerobically when it gives carbon dioxide in the absence of oxygen |
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What are the advantages of breathing through the nose? |
1) Dust and foreign particles are trapped by the hairs in the nostrils 2) Air is warmed and moistened as air passes through the nasal passages 3) Harmful chemicals may detected by small sensory cells in the mucous membrane |
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what are 2 types of cells in the epithelium of the trachea? |
Gland cells and ciliated cells |
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what is the purpose of the gland cells? |
Gland cells secrete mucus to trap dust like particles and bacteria |
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what is the purpose of the ciliated cells? |
Ciliated cells have cilia which sweep the dust trapped mucus up the trachea |
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what are alveoli? |
They are the sites of gaseous exchange in the lungs. |
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How are the oxygen and carbon dioxide concentration gradients between the alveolar air and the blood maintained? |
1) Continuous flow of blood through the bloodcapillaries. 2) Movement of air in and out of the alveoli, caused bybreathing. |
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How do gases diffuse into the alveolus? |
1) Blood entering the lungs from the heart has a lowerconcentration of oxygen and a higher concentrationof carbon dioxide than the atmospheric air enteringthe alveoli in the lungs. 2) Oxygen diffuses from the alveolar air into the bloodcapillaries 3) Carbon dioxide diffuses from blood capillaries to thealveoli |
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What are the adaptations of the lung for efficient gas exchange? |
1. The numerous alveoli in the lungs provide a large surface area to volume ratio for gaseous exchange. 2. The wall of the alveolus is only one cell thick. This provides a short diffusion distance for gases, ensuring afaster rate of diffusion. 3. A thin film of moisture covers the surface of the alveolus. This allows oxygen to dissolve in it. 4. The walls of the alveoli are richly supplied with blood capillaries. The flow of blood maintains the steepconcentration gradient of gases. |
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How is oxygen absorbed? |
1) The alveolar air contains a higher concentration of oxygenthan the blood, oxygen dissolves in the moisture lining thealveolar walls and then diffuses into the blood capillaries. 2) Oxygen combines with the haemoglobin in red blood cells toform oxyhaemoglobin. |
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How is oxygen transported and utilised? |
1) When the blood passes through oxygen-poor tissues, theoxyhaemoglobin releases oxygen, which will then diffusethrough the walls of the blood capillaries into the cells of thetissues |
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How is carbon dioxide removed from your lungs? |
(a) Carbon dioxide produced by tissue cells due to respiration diffuses into blood plasma and then enters into red blood cells.
(b) In RBC, carbon dioxide reacts with water to give carbonic acid, catalyzed by carbonic anhydrase.
(c) Carbonic acid then dissociates into hydrogen carbonate ions/bicarbonateions and hydrogen ions.
(d) The hydrogen carbonate ions diffuse out of red blood cells, into the plasma•
(e) In the lungs, hydrogen carbonate ions diffuse back into red blood cells where they combine with hydrogen ions to form carbonic acid, then into water and carbon dioxide which is catalysed by carbonic anhydrase again
(f) The carbon dioxide diffuses out of the blood into the alveolar space where it is expelled during exhalation. |
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What happens during inspiration/inhalation? |
1. During inhalation, the diaphragm contracts, flattens and movesdownwards. 2. The external intercostal muscles contract while the internalintercostal muscles relax, causing the ribs to move upwards andoutwards. 3. Sternum moves up and forward. 4. The thoracic cavity increases in volume, causing the air pressure ofthe lungs to fall below that of the atmosphere. 5. Air rushes into the lungs. |
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What happens during expiration/exhalation? |
1. During exhalation, the diaphragm relaxes and arches upwards. 2. The internal intercostal muscles contract while the externalintercostal muscles relax, moving the ribs downwards and inwards 3. Sternum returns to its original position. 4. The thoracic cavity decreases in volume, causing the air pressure inthe lungs to be higher than that of the atmosphere. 5. Air flows out of the lungs |
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what is the pathway of air? |
During inhalation: Nostrils → Nasal Passages → Pharynx → Larynx →Trachea → Bronchi → Bronchioles → Alveoli Exhalation is the reverse |
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How does inspired air differ from expired air? |
Inspired Air: Oxygen ----> 21% Carbon dioxide -----> 0.03% Nitrogen ------> 78.0% Water vapour -----> Rarely saturated Temperature ------> Variable Dust particles -----> Usually present Expired air: Oxygen ----> 16.4% Carbon dioxide -----> 4% Nitrogen ------> 78.0% Water vapour -----> saturated Temperature ------> About body temperature (37C) Dust particles -----> Little |
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What are the effects of nicotine? |
1)_Increases heart rate and blood pressure 2) Increase the risk of blood clot 3) Blood clots in arteries leads to increased risk of heart attack 4) Blood clots in blood capillaries in the brain increases risk ofstroke |
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What are the effects of tar? |
1) Increases risk of cancer 2) Paralyses cilia lining air passages. - Dust and irritant are trapped inthe mucus which cannot be removed, increasing risks of chronicbronchitis and emphysema |
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What are the effects of carbon monoxide? |
1) Combines irreversibly with haemoglobin to formcarboxyhaemoglobin, which reduces efficiency of blood totransport oxygen 2) Increases the rate of fatty deposits on the inner arterial wall,increasing risk of atherosclerosis |
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What are the effects of irritants? |
1) Paralyses cilia lining air passages, dust and irritant are trapped inthe mucus which cannot be removed, increasing risks of chronicbronchitis and emphysema. |
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What are the effects of chronic bronchitis? |
1) Prolonged exposure to tar and irritant particles leads to excessive mucus is secretedby the epithelium. 2) The cilia on the epithelium are paralyzed thus mucus and dust particles cannot beremoved.- The air passages become blocked, making breathing difficult. |
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What are the effects of emphysema? |
1) Alveolar walls break down due to persistent and violent coughing. 2) This decreases surface area for gaseous exchange. 3) Lungs lose their elasticity and reduce ability to expel air, causing severebreathlessness as a result. |
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What are the similarities between aerobic and anaerobic respiration? |
- Both of them release energy stored in food substances such as glucose for the cells to use |
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What are the differences between aerobic respiration and anaerobic respiration? |
- During aerobic respiration, water and carbon dioxide are released whereas during anaerobic research, lactic acid is produced - Aerobic respiration produces a large amount of energy while anaerobic respiration releases a small amount of energy - Aerobic respiration requires oxygen while anaerobic respiration does not - The level of fatigue produced during aerobic respiration is less than that of anaerobic respiration |
