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Unformatted text preview: Respiration Custard powder experiment
Custard powder experiment
Did the food contain
• • 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
of water (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
► 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)
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
Respiration energy and mitochondria clip 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:
ADP + Pi ATP The whole process is under the control of enzymes The role of ATP
► 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
to do work Pi Summary
energy (out) cellular respiration cellular
ADP + Pi energ
(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
glyco lysis glucose splitting In glycolysis, a glucose molecule is broken down into
glucose energy released to
quantity of ATP
(2 molecules) series of enzyme
controlled reactions pyruvic acid Glycolysis does not require oxygen Stage 2 – Breakdown of pyruvic acid
The pyruvic acid made in glycolysis
(stage1) still contains a lot of energy
It can only be broken down to release the
rest of the energy in the presence of
oxygen pyruvic acid series of enzyme
reactions energy released
to make large
quantity of ATP
(36 molecules) carbon dioxide + water ATP production – summary
2 ADP + 2 Pi =
2 ATP pyruvic acid
36 ADP + 36 Pi =
36 ATP carbon dioxide + water Summary of ATP production
► 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
anaerobic = in the absence of oxygen In low oxygen conditions or during heavy
In exercise, when not enough oxygen can be exercise
supplied, muscle cells swap to anaerobic
respiration respiration glucose
happens as it does
not require oxygen pyruvic acid
in absence of
acid is turned into
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
glucose pyruvic acid oxygen debt
e.g. during hard
exercise oxygen debt
recovery time lactic acid Anaerobic Respiration
in The same process occurs in plants
and yeast in low oxygen conditions,
e.g. muddy, flooded soils.
e.g. glucose 2 ADP + 2 Pi glycolysis still
2 ATP molecules 2 ATP
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
► 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
www.worldofteaching.com http://www.worldofteaching.com 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.
- Winter '08