respiration2 - Respiration Custard powder experiment...

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Unformatted text preview: Respiration Custard powder experiment Custard powder experiment Did the food contain energy? • • What kind of energy did it have to start with? • What kinds of energy was this released as? Comparing energy in carbohydrates, Comparing energy in carbohydrates, proteins and fats Use different types of food to calculate which will give the most energy Results Results Food Material Carbohydrate Protein Fat Mass of Mass food food (g) Starting Starting temperature of water (0C) of Finishing Finishing temperature of water water (0C) Temperature Temperature rise (0C) rise Calculating energy in food Calculating energy in food ► A given amount of any substance always requires the same amount of energy to produce a particular increase in temperature. ► 1000g of water needs………………..4.2 kJ to make its temperature rise by 1 oC Calculating the energy content of foods Calculating ► The formula to calculate the energy release is ► 4.2 x M x T M = mass of water (g) T=rise in temperature ( °C) 1000 ► Now calculate the energy content of your foods Calorimeter Gases and respiration Gases and respiration ► A: Living Peas B: Dead Peas ► Burn a lighted splint in each gas jar. Do other organisms respire? Do other organisms respire? breathing and respiration 1 Which type of energy does food contain? 1 Which type of energy does food contain? 2 What is this energy converted to by other organisms? Give at least 3 examples. (i) (ii) (iii) 3 What name is given to the process by which organisms release energy? 4 What kind of energy is always released in respiration? The Chemistry of The Respiration Respiration energy and mitochondria clip Adenosine triphosphate Adenosine triphosphate ► The energy released during respiration is not used directly by cells. ► Instead it is used to make a molecule called ATP which stores the energy until it is needed. ATP = Adenosine triphosphate What does ATP do? What does ATP do? ► ATP supplies energy for all the processes that need it. ► For example: ► movement ► chemical reactions ► growth. slow twitch/fast twitch investigation Structure of ATP Structure of ATP adenosine Pi Pi Pi Formation of ATP Formation ATP is made when another molecule called adenosine diphosphate (ADP) is bonded to a third inorganic phosphate (Pi) using the energy released from glucose. Energy from respiration adenosine Pi Pi + Pi Enzymes adenosine Pi Pi Pi Energy Rich bond formed Summarised as: Summarised as: ADP + Pi ATP The whole process is under the control of enzymes The role of ATP The ► ATP stores the energy in the third bond of the molecule ► The energy is released when that bond is broken to release the third inorganic phosphate (Pi) . adenosine Pi Pi Pi ATP Enzymes adenosine Pi ADP Pi + Energy released to do work Pi Summary Summary ATP ATP energy (out) cellular respiration cellular respiration energy (in) ADP + Pi energ y (out) cell activities cell activities The whole process is an enzyme controlled reaction. Aerobic Respiration Aerobic respiration = respiration with oxygen. g lu c o s e + OXYGEN OXYGEN e ne rg y + c a rb o n d io xid e + wa te r (to m a ke AT P ) Aerobic respiration happens in 2 stages: Aerobic respiration happens in Stage 1 – Glycolysis Stage glyco lysis glucose splitting In glycolysis, a glucose molecule is broken down into pyruvic acid. glucose energy released to make small quantity of ATP (2 molecules) series of enzyme controlled reactions pyruvic acid Glycolysis does not require oxygen Stage 2 – Breakdown of pyruvic acid Breakdown The pyruvic acid made in glycolysis The (stage1) still contains a lot of energy (stage1) It can only be broken down to release the rest of the energy in the presence of presence of oxygen. oxygen pyruvic acid series of enzyme controlled reactions energy released to make large quantity of ATP (36 molecules) carbon dioxide + water ATP production – summary ATP glucose 2 ADP + 2 Pi = 2 ATP pyruvic acid 36 ADP + 36 Pi = 36 ATP carbon dioxide + water Summary of ATP production Summary ► Stage 1 and 2 release all the chemical energy in one molecule of glucose to make a total of 38 ATP ATP molecules. 2 molecules ATP from glucose → pyruvic acid 36 molecules ATP from pyruvic acid → carbon­ dioxide + water Total 38 molecules ATP Anaerobic Respiration (in animals) anaerobic = in the absence of oxygen In low oxygen conditions or during heavy heavy In exercise, when not enough oxygen can be exercise supplied, muscle cells swap to anaerobic respiration respiration glucose glycolysis still happens as it does not require oxygen pyruvic acid in absence of oxygen pyruvic acid is turned into lactic acid. lactic acid 2 ADP + 2 Pi 2 ATP A build up of lactic acid produces muscle fatigue. fatigue A build up of lactic acid produces Muscle fatigue makes muscles ache and contract less powerfully. A recovery period is needed. During this time more oxygen is taken in to convert the lactic acid back into pyruvic acid again. The volume of oxygen needed is called the oxygen debt. debt Summary Summary glucose pyruvic acid oxygen debt e.g. during hard exercise oxygen debt repaid during recovery time lactic acid Anaerobic Respiration Anaerobic in plants in The same process occurs in plants The and yeast in low oxygen conditions, e.g. muddy, flooded soils. e.g. glucose 2 ADP + 2 Pi glycolysis still happens, producing 2 ATP molecules 2 ATP pyruvic acid This time in absence of oxygen, pyruvic acid is turned into carbon dioxide and ethanol This is irreversible ethanol + carbon dioxide Comparison of aerobic and Comparison of aerobic and anaerobic respiration Aerobic respiration Anaerobic Respiration in animals in plants and yeast Oxygen required? yes no no Glycolysis occurs yes yes yes ATP yield 38ATP 2ATP 2ATP Glucose completely broke down? yes no no End products Carbon dioxide Lactic acid Ethanol and carbon Task Task ► Prepare a series of PowerPoint slides which show the importance of anaerobic respiration in the brewing and bread­making processes. ► Prepare a couple of slides to show the role of anaerobic respiration in the production of cheese and yogurt. [Pages 4 ­14 of your textbook will help you with these tasks if you are finding it difficult to find information on the internet]. This powerpoint was kindly donated to is home to over a thousand powerpoints submitted by teachers. This is a completely free site and requires no registration. Please visit and I hope it will help in your teaching. ...
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This note was uploaded on 11/07/2011 for the course BIOLOGY 100 taught by Professor Staff during the Winter '08 term at BYU.

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