Presentation on theme: "Glucose + oxygen -> carbon dioxide + water (+ energy)"— Presentation transcript:
1 Glucose + oxygen -> carbon dioxide + water (+ energy) Relevant LO’s…B2.6 Aerobic and anaerobic respirationB2.6.1 Aerobic RespirationThe chemical reactions inside cells are controlled by enzymesDuring aerobic respiration (respiration that uses oxygen) chemical reactions occur that:Use glucose (a sugar) and oxygenRelease energyAerobic respiration takes place continuously in both plants and animalsMost of the reactions in aerobic respiration take place inside mitochondriaAerobic respiration is summarised by the equation:Glucose + oxygen -> carbon dioxide + water (+ energy)Energy that is released during respiration is used by the organism. The energy may be used:To build larger molecules from smaller onesIn animals, to enable muscles to contractIn mammals and birds, to maintain a steady body temperature in colder surroundingsIn plants, to build up sugars, nitrates and other nutrients into amino acids which are then built up into proteinsDuring exercise a number of changes take place:The heart rate increasesThe rate and depth of breathing increasesThese changes increase the blood flow to the muscles and so increase the supply of sugar and oxygen and increase the rate of removal of carbon dioxideMuscles store glucose as glycogen, which can then be converted back to glucose for use during exercise
2 Relevant LO’s B2.6.2 Anaerobic Respiration During exercise, if insufficient oxygen is reaching the muscles they use anaerobic respiration to obtain energyAnaerobic respiration is the incomplete breakdown of glucose and produces lactic acid**As the breakdown of glucose is incomplete, much less energy is released than during aerobic respiration. Anaerobic respiration results in an oxygen debt that must be repaid in order to oxidise lactic acid to carbon dioxide and water** (HT only)If muscles are subjected to long periods of vigorous activity, they become fatigued and stop contracting efficiently. One cause of muscle fatigue is the build up of lactic acid in the muscles. Blood flowing through the muscles removes the lactic acid
4 Short Answer Questions Respiration is a chemical process.Where does respiration take place? Circle the correct answer (1)chloroplasts mitochondria nuclei ribosomesb) Which food material is used in respiration?_________________________________________________________________ (1)c) Name the two waste materials that are produced in respiration._________________________________________________________________ (2)d) Respiration is important in muscle contraction. Explain why.2. a) Copy and complete the word equation for aerobic respiration.Oxygen + __________ -> Water + __________ (+ energy)b) i) Which substance is missing in anaerobic respiration?ii) What is made during anaerobic respiration?iii) Muscles get tired during anaerobic respiration. Explain why.
5 Past Paper Question – Longer Answer In this question, you will be assessed on using good English, organising information clearly and using specialist terms where appropriateThe bar charts show what happens in an athlete’s muscles when running in two races of different distances.Rate at which muscles transfer energy (average)The equations show two processes that occur in muscle cells.Use all the information to explain what happens in the athlete’s muscles when running in the two races (6)Aerobic RespirationGlucose + Oxygen -> Carbon Dioxide + WaterAnaerobic RespirationGlucose -> Lactic Acid100m race m raceRate at which muscles produce carbon dioxide (average)
6 5-6 marks 3-4 marks 1-2 marks 0 marks Use all the information to explain what happens in the athlete’s muscles when running in the two races(6 marks)5-6 marks3-4 marks1-2 marks0 marksThere is a clear, balanced and detailed explanation about the differences between the two races in terms of aerobic and anaerobic respirationThe answer is coherent and in a logical sequenceIt contains a range of appropriate or relevant specialist terms used accuratelyThe answer shows few errors in spelling, punctuation and grammarThere is some attempt to explain the differences between the two races in terms of respirationThe answer has some structure and organisationThe use of specialist terms has been attempted, but not always accuratelyThere may be some errors in punctuation, spelling and grammarThere is a brief description of the differences between the two races, which has little clarity and detailThe answer is poorly constructed with an absence of specialist terms or their use demonstrates a lack of understanding of their meaningThe spelling, punctuation and grammar are weakNo relevant contentExamples of biology points made in the response:Energy is transferred faster in the 100m raceCarbon dioxide produced faster during the 1500m race/moreCarbon dioxide producedCorrect reference to twice/half as fast in either/both casesRespiration during 100m race (mainly) anaerobicRespiration during 1500m race (mainly) aerobicAerobic respiration produced carbon dioxideAnaerobic respiration produced lactic acid