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© Boardworks Ltd 2004 1 of 20 © Boardworks Ltd 2005 1 of 26 KS3 Biology 8B Respiration.

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Presentation on theme: "© Boardworks Ltd 2004 1 of 20 © Boardworks Ltd 2005 1 of 26 KS3 Biology 8B Respiration."— Presentation transcript:

1 © Boardworks Ltd of 20 © Boardworks Ltd of 26 KS3 Biology 8B Respiration

2 © Boardworks Ltd of 20 © Boardworks Ltd of 26 8B Respiration Contents Releasing energy The circulation system Summary activities The breathing system Anaerobic respiration

3 © Boardworks Ltd of 20 © Boardworks Ltd of 26 The body needs a constant supply of energy which comes from digested food. Glucose from digested carbohydrate is an important substance that contains stored chemical energy. How is digested food used by the body? When glucose reacts with oxygen a lot of energy is released. The release of energy from glucose is called… In the body’s cells, glucose and oxygen react to release energy. Some of this is released as heat and the rest is used by the cells. respiration

4 © Boardworks Ltd of 20 © Boardworks Ltd of 26 from the digestive system from the breathing system useful! waste product exhaled This type of respiration is called aerobic respiration because energy is released with oxygen. Respiration is the process that the body uses to release energy from digested food (glucose): What is respiration? carbon dioxide glucose oxygen water energy How do the glucose and oxygen needed for aerobic respiration get to the all the body’s cells?

5 © Boardworks Ltd of 20 © Boardworks Ltd of 26 Aerobic respiration: word equation activity

6 © Boardworks Ltd of 20 © Boardworks Ltd of 26 When something burns, heat and light energy are released and carbon dioxide and water are also produced, so combustion is similar to respiration. Burning is the reaction between a fuel and oxygen. This reaction is called combustion: Comparing respiration and combustion carbon dioxide fuel oxygen water However, combustion is different because it is not a controlled reaction. Respiration is a controlled reaction which slowly releases energy from food in the body’s cells and the cells do not catch fire!

7 © Boardworks Ltd of 20 © Boardworks Ltd of 26 8B Respiration Contents Releasing energy The circulation system Summary activities The breathing system Anaerobic respiration

8 © Boardworks Ltd of 20 © Boardworks Ltd of 26 The dissolved food and oxygen needed for respiration are carried around the body by the circulation system. The circulation system includes the blood, blood vessels, the heart and the lungs. Which part of the circulation system actually carries dissolved food and oxygen to the body’s cells? The body’s transport system body’s cells body’s cells lungs

9 © Boardworks Ltd of 20 © Boardworks Ltd of 26 The blood carries oxygen and dissolved food to all the body’s cells so that respiration can take place. Blood

10 © Boardworks Ltd of 20 © Boardworks Ltd of 26 The heart is made of very special muscle called cardiac muscle. This is because it has to keep beating for the whole of a person’s life! If you tried to do the same action repeatedly (like the heart does), your muscles would get tired and after a while stop working. Your beating heart For example, if you keep clenching and unclenching your hand, it will get tired and may even start to get cramp. Why is it important for respiration that the heart keeps beating?

11 © Boardworks Ltd of 20 © Boardworks Ltd of 26 What happens to the pulse rate whilst someone is running? The body needs to release more energy: so oxygen and glucose need to reach muscle cells quickly; so blood is pumped around the body faster; so the pulse is faster. Different types of activity What happens to the pulse rate whilst someone is sleeping? The body needs to release less energy: so oxygen and glucose need to reach muscle cells slowly; so blood is pumped around the body slower; so the pulse is slower.

12 © Boardworks Ltd of 20 © Boardworks Ltd of 26 8B Respiration Contents Releasing energy The circulation system Summary activities The breathing system Anaerobic respiration

13 © Boardworks Ltd of 20 © Boardworks Ltd of 26 The breathing system is used by the body to get the oxygen needed for respiration. It is also use to get rid of the waste product of respiration, the gas carbon dioxide. Breathing in and breathing out are separate processes in the body: What is breathing? Breathing in is also known as inhalation. When you inhale you breathe in air, including oxygen, into your lungs. Breathing out is also known as exhalation. When you exhale you breathe out the contents of our lungs and getting rid of the waste gas carbon dioxide.

14 © Boardworks Ltd of 20 © Boardworks Ltd of 26 Inhalation

15 © Boardworks Ltd of 20 © Boardworks Ltd of 26 In the lungs, oxygen travels to thousands of tiny air sacs called alveoli. These are covered with tiny blood vessels. The alveoli The alveoli give the lungs a huge surface area which is equal in size to the area of a tennis court!

16 © Boardworks Ltd of 20 © Boardworks Ltd of 26 Gas exchange takes place in the alveoli – oxygen is transferred into the blood and carbon dioxide moves out of the blood. Each alveolus has a thin wall so that gas exchange between Gas exchange the lungs and the blood can take place quickly.

17 © Boardworks Ltd of 20 © Boardworks Ltd of 26 Exhalation

18 © Boardworks Ltd of 20 © Boardworks Ltd of 26 What are the differences between inhaled and exhaled air? inhaled air nitrogen (78%) oxygen (21%) carbon dioxide (0.04%) other Comparing inhaled and exhaled air How could you test for the differences between inhaled and exhaled air? exhaled air nitrogen (78%) oxygen (17%) carbon dioxide (4%) other

19 © Boardworks Ltd of 20 © Boardworks Ltd of 26 8B Respiration Contents Releasing energy The circulation system Summary activities The breathing system Anaerobic respiration

20 © Boardworks Ltd of 20 © Boardworks Ltd of 26 aerobic When the body is able to supply the cells with the oxygen and glucose that they need, it carries out aerobic respiration. Anaerobic respiration anaerobic When the body cannot supply the cells with the oxygen needed to break down glucose, then it has to carry out anaerobic respiration. Energy is released without oxygen: Aerobic and anaerobic respiration Aerobic respiration carbon dioxide glucose oxygen water energy lactic acid energy glucose

21 © Boardworks Ltd of 20 © Boardworks Ltd of 26 When anaerobic respiration takes place, the lactic acid produced soaks the muscle cells and prevents muscles from doing their job. This causes fatigue and sometimes cramp. After activity that has lead to anaerobic respiration, the person involved pants and breathes heavily. This happens because they need lots of oxygen to get rid of lactic acid that has built up in their body. Not enough oxygen! lactic acid energy glucose carbon dioxide lactic acid oxygen water

22 © Boardworks Ltd of 20 © Boardworks Ltd of 26 Anaerobic respiration: word equation activity

23 © Boardworks Ltd of 20 © Boardworks Ltd of 26 8B Respiration Contents Releasing energy The circulation system Summary activities The breathing system Anaerobic respiration

24 © Boardworks Ltd of 20 © Boardworks Ltd of 26 Glossary aerobic – The type of respiration that occurs with oxygen. alveoli – Tiny air sacs in the lungs where gas exchange takes place. anaerobic – The type of respiration that occurs without oxygen. exhalation – The process of breathing out. glucose – A type of sugar that the body releases energy from during respiration. inhalation – The process of breathing in. respiration – The process that the body uses to release energy from digested food.

25 © Boardworks Ltd of 20 © Boardworks Ltd of 26 Anagrams

26 © Boardworks Ltd of 20 © Boardworks Ltd of 26 Multiple-choice quiz


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