3Remember respiration is a chemical process Define respiration as the chemical reactions that break down nutrient molecules in living cells to release energy.Remember respiration is a chemical processWhich releases energy from foodDon’t confuse it with the exchange of gases or breathing
4State the uses of energy in the body of humans: muscle contraction,protein synthesis,cell division,growth,the passage of nerve impulsesthe maintenance of a constant body temperatureALL these processes require energyYou need to be able to quote these
6Remember aerobic respiration needs oxygen It releases a lot of energy Define aerobic respiration as the release of a relatively large amount of energy in cells by the breakdown of food substances in the presence of oxygen.Remember aerobic respiration needs oxygenIt releases a lot of energy
7State the word equation for aerobic respiration. Food + oxygen carbon dioxide + water
8State the equation for aerobic respiration using symbols C6H12O6 + 6O2 → 6CO2 + 6H2OLearn this equationYou’ll need it if you’re doing the higher tier
10Define anaerobic respiration the release of a relatively small amount of energy by the breakdown of food substancesin the absence of oxygen.Because the food is not completely broken down some of the energy remains in the waste products
11State the word equation for anaerobic respiration in muscles during hard exerciseglucose → lactic acidand the microorganism yeastglucose → alcohol + carbon dioxideNote that a lot of the energy here remains locked up in the lactic acid or alcohol
13Look at the diagram below and compare the number of ATP molecules Compare aerobic respiration and anaerobic respiration in terms of relative amounts of energy released.Aerobic respiration produces much more energy ATP than anaerobic respirationLook at the diagram below and compare the number of ATP molecules
14State the balanced equation for anaerobic respiration in musclesC6H12O6 → 2C3H6O3and the microorganism yeastC6H12O6 → 2C2H5OH + 2CO2using symbolsYou should learn theseNote that no carbon dioxide is produced in anaerobic respiration in animals
15Describe the role of anaerobic respiration in yeast during brewing and bread-making.
16Bread making The fermentation process serves three primary purposes: To produce carbon dioxide gas to create a light and airy texture in the breadTo enhance the flavour of the breadTo change the protein structure of the bread to prevent a chewy texture
17Beer making Similar to baking bread, yeast is critical to making beer. Yeast is added to the wort to turn the sugars into alcohol and carbon dioxideThis process is called fermentation.
18Describe the effect of lactic acid in muscles during exercise (include oxygen debt in outline only). Lactic acid build up is often blamed for post workout muscle fatigue and pain
19During short intense burst of exercise such as sprinting Energy is generated anaerobically or without oxygen.Lactic acid builds upWhen you stop exercising you are still breathing heavily.
20This is your body taking in extra oxygen to 'repay' the oxygen debt. When you stop sprinting and start to recover you will actually need more oxygen to recoverThis is oxygen is used to break down the lactic acidThe difference between the oxygen the body required and what it actually managed to take in during the sudden sprint is called oxygen deficit.
22List the features of gas exchange surfaces in animals. Large surface areaSo diffusion is more efficientMoistSo gases can dissolveGood blood supplyTo remove the oxygen and maintain concentration gradientVentilation systemTo bring more supplies of oxygen
23Cross-section through leaf Circulation of gases in and out of leaf
24This is a useful website Identify on diagrams and name the larynx, trachea, bronchi, bronchioles, alveoli and associated capillariesThis is a useful website
25The Breathing SystemFunction is to take air into and out of the lungs to allow gas exchangeOxygen moves from the lung to the bloodCarbon dioxide moves from the blood into the lungGases move by diffusion
32Mucus traps the pathogens and particles Explain the role of mucus and cilia in protecting the gas exchange system from pathogens and particles.Mucus traps the pathogens and particlesCilia move the mucus upwards to the mouth where it is swallowed
33The structure of the trachea C-shaped ring of cartilageCiliated cells
38You need to learn the sequence of events here Describe the role of the ribs, the internal and external intercostal muscles and the diaphragm in producing volume and pressure changes leading to the ventilation of the lungsYou need to learn the sequence of events here
39When we breathe in… Intercostal muscles contract So, ribcage moves out and upDiaphragm contracts and flattensThe volume (or space) inside the thorax increasesThe lungs are stretched to fill that space
40The pressure inside the lungs decreases Now the pressure outside the body is higher than the pressure in the lungsSo, air rushes into the lungsTHE LUNGS INFLATE - This is inhalation
41When we breathe out… Intercostal muscles relax So, ribcage moves in and downDiaphragm relaxes and curves upThe volume (or space) inside the thorax decreasesThe lungs are return to their original size
42The pressure inside the lungs increases Now the pressure inside the lungs higher than the pressure outside the bodySo, air rushes out of the lungsThis is exhalation
44Breathing and gas exchange There are some good videos here
45What is lung capacity?Lung capacity is the maximum volume of air that can be breathed out after a maximum breath inWhat is your lung capacity?Adult male = 4 litresAdult female = 3 litres
46State the differences in composition between inspired and expired air. Not all the oxygen is removed from the airExhaled air still contains some oxygen but has much more carbon dioxide and water vapour than inhaled air
47Is exhaled air different? ComponentInhaled airExhaled airOxygen21%17%Carbondioxide0.04%4%Nitrogen78%WatervapourVariableSaturated
48Lime water goes cloudy when carbon dioxide is bubbled through it Use lime water as a test for carbon dioxide to investigate the differences in composition between inspired and expired air.Lime water goes cloudy when carbon dioxide is bubbled through itThe experiment below uses a different indicator but lime water could be used with the same apparatus
50Here are the results using limewater Breathe in and out through the long tubeOne tube has inhaled air bubbled through itThe other has exhaled air bubbled through it
51Investigate and describe the effects of physical activity on rate and depth of breathing You can try this on yourself or family membersTAKE CARE if anyone has heart or lung problems !!!
52EFFECT OF EXERCISE ON HEART RATE AND BREATHING Measure your heart (pulse) rate breathing rate at rest.Do one lot of exercise (10 press ups OR run or walk up one flight of stairs)Take the pulse and breathing rate againWait till you have fully recovered and your pulse has gone back to normalThen do 2 lots of exercise (20 press ups OR run/walk up two flights of stairs)Repeat with three and four lots of exercise.
53RESULTS Plot a graph of heart rate against amount of exercise Plot another graph of breathing rate against exercisePlot a scatter graph of heart rate against pulse rateYou could try this with other members of your family or friends
54Conclusions What are trends in your results? In a couple of sentences explain the relationship between exercise, heart rate and breathing rate.What is the biological explanation for your results?
55EvaluationLook at your method and explain whether or not this was an accurate measure of the effects of exercise on the heart and lungs.Suggest some improvements to this experimentWrite up and send me your experiment
56changes in the rate at which tissues respire Explain the link between physical activity and rate and depth of breathingin terms ofchanges in the rate at which tissues respireand therefore of carbon dioxide concentrationand pH in tissuesand in the blood
57Effects of exerciseThe body needs much more Oxygen. The breathing becomes faster and deeper and produces a large vol. of Oxygen. More Carbon Dioxide is produced which is the waste product, which blood carries back to the lungs to be exhaledPeople taking part in exercise go red because the Veins carrying warm blood back to the heart divert the blood nearer the skins surface. This is called Vasodilation. The heat is then lost through radiation through the skin.Because the body needs more blood to carry more Oxygen and waste products the blood is diverted from parts of the body that don’t require it for example the blood in the stomach is reduced.The heart beats faster and pumps blood around the body faster. The heart also fills up with more blood and squeezes more blood out with each contraction. The Heart Rate, Stroke Vol., Cardiac Output, and Blood Pressure all increase during exercise.More H2O and heat are produced and eliminated by sweating and exhaling. The blood must carry these waste products away from the muscle cells, this is why the breath is hot and moist during exercise. Muscles are required to contract and relax in specific areas of the body.
58Effects on pH The pH of the blood is maintained at about pH 7 When carbon dioxide (CO2) gas dissolves in water, it forms carbonic acidThis lowers the blood pHThe pH of the tissue fluid also lowersThis is detected by the brain which increases the heart and breathing rate
59What happens when we exercise? Exercise increases the rate of which process?RESPIRATIONWhy?More energy needed for muscle contractionHow?ATP is formed when food is broken down.This releases more carbon dioxide
60How does the breathing system respond to exercise? Exercise causes the rate and depth of breathing to increaseThe heart rate increasesThe stroke volume of the heart increases
61This increases the supply of oxygen and glucose to the muscles And increases the rate of removal of carbon dioxide, lactic acid and heat from the muscles
63EFFECT OF EXERCISE ON HEART RATE AND BREATHING Measure your heart (pulse) rate breathing rate at rest.Do one lot of exercise (10 press ups OR run or walk up one flight of stairs)Take the pulse and breathing rate againWait till you have fully recovered and your pulse has gone back to normalThen do 2 lots of exercise (20 press ups OR run/walk up two flights of stairs)Repeat with three and four lots of exercise.
64tar, nicotine, carbon monoxide, smoke particles Describe the effects of tobacco smoke and its major toxic components on the gas exchange system.tar,nicotine,carbon monoxide,smoke particles
66Tar Tar causes cancer of the lungs, mouth and throat. It coats the surface of the breathing tubes and the alveoli.This causes coughing and damages the alveoli, making it more difficult for gas exchange to happen.
67SmokeCells in the lining of the breathing tubes produce sticky mucus to trap dirt and microbes.Cells with tiny hair-like parts, called cilia, normally move the mucus out of the lungs.Hot smoke and tar from smoking damages the cilia.So smokers cough to move the mucus and are more likely to get bronchitis.
68NicotineNicotine is addictive - it causes a smoker to want more cigarettes.Nicotine also increases the heart rate and blood pressure, and makes blood vessels narrower than normal.This can lead to heart disease.
69Carbon monoxideCarbon monoxide is a gas that takes the place of oxygen in red blood cells.This reduces the amount of oxygen that the blood can carry.This means that the circulatory system has to work harder, causing heart disease.