Factors affecting Respiration. Level 4/National 4

Transcription

1 Factors affecting Respiration Level 4/National 4

2 Learning Intentions By investigating respiration, I can describe its purpose in living organisms and can describe factors that affect it. Success criteria I can describe how respiration can occur with and without oxygen in both animal and yeast cells and know what products are formed. I can state that more energy is released per molecule of glucose when oxygen is present. I can state that respiration is an enzyme controlled process and so is affected by temperature.

3 Exploding can Exploding Can Demo - YouTube Activity 1 Make a Fire Ball with Lycopodium Powder - YouTube

4 Burning food Activity 1 What are the products of this chemical reaction????

5 Burning Food Results Food sample 1 2 Starting temperature of water ( C) Temperature after burning ( C) Temperature Change ( C) Diagram Label the following diagram and add the missing piece of apparatus.

6 What is respiration? Living organisms need a constant supply of energy which comes from digested food. Green plants make their own food by photosynthesis whereas animals need to feed. Respiration is the process that releases the energy from food for many uses in cells. Use of Energy in Cells Q46 summary page 48 level 4/Nat 4

7 Respiration Respiration can be summarised by the following word equation: glucose + oxygen carbon dioxide + water + energy Respiration using oxygen is called Aerobic Respiration. Carbon dioxide and water are waste products. In animals, carbon dioxide is breathed out. Water is got rid of in several ways. Can you suggest how??

8 Activity 2 Respirometer DVD Energy 3mins Coloured dye woodlouse sodium hydroxide

9 Respiration

10 Aerobic Respiration

11 Cells need oxygen to release energy from food during aerobic respiration. O 2 O 2 O 2 O 2 O 2 11

12 Cells release carbon dioxide during Complete page 48 summary Nat 4 CO aerobic respiration. CO 2 CO 2 2 CO CO 2

13 Comparing inhaled and exhaled air What are the differences between inhaled and exhaled air? inhaled air exhaled air nitrogen (78%) oxygen (21%) carbon dioxide (0.04%) other nitrogen (78%) oxygen (17%) carbon dioxide (4%) other How could you test for the differences between inhaled and exhaled air? BBC - Learning Zone Class Clips - Respiration in humans - Science Video

14 How much energy is in food? By burning a sample of food, we can see how much energy it releases in heating up a volume of water. COLLECT: Testube 20ml water thermometer food samples clamp stand deflagrating spoon.

15 Instructions 1. Place 20ml water into a test tube 2. Measure the temperature of water with a thermometer and record in table. 3. Place food sample onto deflagrating spoon and light using a bunsen burner. 4. Hold burning food sample beneath test tube of water until it stops burning. 5. Measure temperature of water and note in table.

16 Results Food sample Starting temperature of water ( C) Temperature after burning ( C) Temperature Change ( C) Conclusion

17 What foods contain the most energy? Activity 3 Sort the food labels into order by how much energy the food contains. What type of foods contain the most energy?

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20 Does respiration use up oxygen? Oxygen is needed by living cells to release energy from food during respiration.

21 Does respiration release heat? Activity 4 Page 50 summary Nat 4 Teacher demonstration A B

22 Fermentation in yeast

23 Cells release heat energy during respiration.

24 Does respiration release carbon Activity 3 dioxide? Gently blow air through a straw into a test tube containing Bicarbonate Indicator. What happens to the colour of the indicator? What gas must be in exhaled air? What process happening in cells produces this gas?

25 Does respiration release carbon dioxide? Conclusion After a few hours, the bicarbonate indicator in tubes A, B and C turns from red to yellow showing that each organism has given out carbon dioxide during respiration. Tube D, the control remained unchanged.

26 What does yeast need to reproduce and grow?? Carbon dioxide gas control

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29 How can respiration be measured? Write the equation for aerobic respiration in yeast How can respiration be measured?

30 Anaerobic respiration What happens when all of the oxygen is used up?? Remove the balloon from your flask Write down any observations that you make.

31 Fermentation Write the heading Fermentation Watch the Twig video fermentation Write short notes on fermentation IN YOUR OWN WAY

32 Respiration without oxygen Yeast Yeast are capable of carrying out respiration in the absence of oxygen under certain circumstances. When respiration occurs without the presence of oxygen it is called anaerobic respiration. Fermentation of sugar by yeast is an example of anaerobic respiration. glucose alcohol + carbon dioxide + energy This process is made use of by brewers and winemakers who ensure no oxygen is available (If oxygen is available, yeast will carry out aerobic respiration as shown instead).

33 Is respiration affected by temperature? Pupil Activity Within your cooperative groups, follow your teachers instructions and plan an investigation to test if respiration in yeast during bread making is affected by temperature. Discuss your plan with your teacher before carrying out the investigation. Record your findings then report them back to your class.

34 Investigate What factors might affect respiration in yeast?????

35 apparatus Gas syringe sugars Glass tubing

36 Planning

37 What variable will I Investigate

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39 Variables that are kept the same 25 ml water (volume)/yeast solution 2 spatulas yeast solution (mass) 4 small spatulas of sugar (mass) Water bath at 37 0 C (temperature) 5 minutes

40 Can respiration be measured? Demonstration Your teacher will show you how you can measure respiration in yeast using an carbon dioxide sensor connected to a laptop computer. This measures how quickly the yeast releases carbon dioxide and so tells us how fast respiration is happening. Can you think of any advantages of using this high tech method?

41 Respiration without oxygen Animals DVD Biological reactions 5mins When our muscles don t receive enough oxygen during hard exercise they carry out anaerobic respiration. A substance called Lactic Acid is made which makes muscles feel sore and tired. glucose lactic acid + little energy The Lactic Acid eventually gets broken down when we stop exercising and breathe in lots of oxygen.

42 Anaerobic Respiration

43 What kind of respiration releases the most energy? Aerobic respiration releases much more energy per molecule of glucose than anaerobic respiration so is said to be much more efficient.

44 Is respiration affected by other factors? Respiration in cells is controlled by enzymes. From your earlier work, you should be able to give examples of factors which could affect how well enzymes work. How many can you name? Complete page 53 summary Nat 4

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47 Learning Intentions By investigating respiration, I can describe its purpose in living organisms and can describe factors that affect it. Success criteria I can describe how respiration can occur with and without oxygen in both animal and yeast cells and know what products are formed. I can state that more energy is released per molecule of glucose when oxygen is present. I can state that respiration is an enzyme controlled process and so is affected by temperature.