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Weekly plan 9
Respiration 3
Student book links
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Specification links
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1.4.8
1.4.9
4.4.1 (t)–(w)
Link to GCSE/AS specification
Suggested time allowed (includes contact and non-contact time):
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GCSE Respiration
Nutrition and diet
3 hours
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AS 1.1.1 Cell structure
1.1.2 Cell membranes
2.1.1 Biological molecules
2.1.2 Nucleic acids
2.1.3 Enzymes
Suggested teaching order
Weekly learning outcomes
Student should be able to:
 Explain why anaerobic respiration produces a much lower yield of ATP than aerobic respiration.
 Compare and contrast anaerobic respiration in mammals and in yeast.
 Define the term: respiratory substrate.
 Explain the difference in relative energy values of carbohydrate, lipid and protein respiratory
substrates.
Key words
Anaerobic respiration
Relative energy value
1.
2.
3.
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5.
6.
Glycolysis as a common factor to aerobic and anaerobic
respiration
Effect of lack of oxygen
Lactate fermentation
Alcoholic fermentation
Define the term: respiratory substrate
Energy values of different substrates
How Science Works
Respiratory substrate
Lactate fermentation
Aerobic respiration
Alcoholic fermentation
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HSW 5 Investigate the effect of a variable on the rate of
respiration or compare aerobic and anaerobic respiration in
yeast. Calculate rates of respiration; plot graphs showing the
effect of a variable on respiration; and identify and evaluate
the limitations of measuring respiration rate.
Learning styles (S = Starter activities, M = Main activities, P = Plenary activities)
ICT activities
Kinaesthetic
Activities S1–3
Activities M1–7
Activities P2–3
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Interpersonal
Activities S1–3
Activities M1–7
Activities P1–3
Auditory
Activities S1–3
Activities M1–7
Activities P1–3
Visual
Activities S1–3
Activities M1–7
Activities P1–3
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See Activity S2 below – writing risk assessments using a word
processor and collating ideas via an IWB.
See Activity S3 below – use of a spreadsheet to help with
calculations.
See Activities M1–7 below – writing investigations using a
word processor and processing data using a spreadsheet.
The web links referred to here are some that the author has found personally helpful but are not intended to be a comprehensive list, many other
good resources exist.
© Pearson Education Ltd 2009
This document may have been altered from the original
1
Weekly plan 9
Suggested starter activities
Equipment
Teacher notes
1. Introduce each practical investigation and its aims to the
class.
2. As a class, conduct a risk assessment for each Practical
activity in the Main activities below.
3. In groups, students use nutritional data from cereal packets
to calculate energy values from different food groups.
Cereal packets
Suggested main activities
Equipment
Teacher notes
1. Practical activity 10: Determining the respiration rate using
respirometers
See technician worksheet.
See teacher worksheet.
2. Practical activity 11: Determining the respiratory quotient
(RQ) of germinating seeds
See technician worksheet.
See teacher worksheet.
3. Practical activity 12: Investigating dehydrogenase activity in
anaerobic respiration of yeast
See technician worksheet.
See teacher worksheet.
4. Practical activity 13: To investigate the effect of the type of
substrate on yeast respiration
See technician worksheet.
See teacher worksheet.
5. Practical activity 14: The effect of temperature on yeast
respiration
See technician worksheet.
See teacher worksheet.
6. Practical activity 15: The effect of ethanol on yeast
respiration
See technician worksheet.
See teacher worksheet.
7. Practical activity 16: Comparing anaerobic and aerobic
respiration
See technician worksheet.
See teacher worksheet.
Suggested plenary activities
Equipment
Teacher notes
1. Collate practical results and conclusions from the Practical
activities as a class.
2. Each student has to stand up and say one thing they have
learned from this topic.
3. In groups, students draw a concept map showing how yeast
respiration is affected by the variables investigated in the Main
activities above.
Any other student who has learned the same thing must
also stand up – all those standing need to swap places.
A3 paper
© Pearson Education Ltd 2009
This document may have been altered from the original
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Weekly plan 9
Homework suggestions
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Compare and contrast anaerobic respiration in mammals and in yeast.
Research a booklet which examines the industrial applications of anaerobic respiration.
Complete the write-up of all the Practical activities.
Cross-curriculum links
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Physics – forms of energy
Chemistry – redox, mole calculations
Physical education – aerobic and anaerobic respiration
Home economics – alcohol and bread production
PSHE – diet
Stretch and Challenge
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The links to the AS specification stated on page 1 are a good opportunity to develop Stretch and Challenge skills.
Pasteur observed that yeast consumes far more glucose when growing under anaerobic conditions than when growing under aerobic conditions. Scientists now know
that the rate of ATP production by anaerobic glycolysis can be up to 100 times faster than that of oxidative phosphorylation, but much glucose is consumed and the
end product, ethanol, still has a lot of potential chemical energy. When mammalian muscle tissues are rapidly using ATP, they can regenerate it almost entirely by
anaerobic glycolysis and lactate fermentation. A great deal of glucose is used but this process is not as wasteful as ethanol fermentation – suggest why.
Palmitic acid produces eight 2-carbon fragments. This requires seven turns of the -oxidation cycle. For each turn of the -oxidation cycle, one reduced NAD and one
reduced FAD are produced. The seven FAD and seven NAD are reoxidised via oxidative phosphorylation, the hydrogen from reduced NAD being involved in
chemiosmosis and ATP synthesis. Each acetyl group enters the Krebs cycle and produces one reduced FAD and three reduced NAD, as well as one ATP by
substrate-level phosphorylation. Eight turns of the Krebs cycle are needed to deal with the eight fragments produced during -oxidation. The energy equivalent to the
hydrolysis of two ATP molecules is used to combine the fatty acid with acetyl CoA. Calculate the net gain of ATP for one molecule of palmitic acid, oxidised via oxidation and the Krebs cycle.
Potential misconceptions
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Students can find the concept of energy difficult to understand.
Some students may still think that respiration equates to breathing.
Some students think ATP is a form of energy rather than a storage molecule.
It is important to clarify the nature of reduction and oxidation reactions early on, as these can be confusing at GCSE.
When you present an overview to the students, it is worth doing so against a diagram of the cell – they can link the stages to the different locations early on.
Students often confuse NAD with NADP, and NAD with FAD, and these can also appear in diagrams with H added, e.g. NADH! – refer to oxidised NAD or reduced
NAD as appropriate.
Only present the level of detail given in the textbook – although many other textbooks will give much more detail, it is more important for students to pick up the main
ideas rather than the detail of every compound produced.
© Pearson Education Ltd 2009
This document may have been altered from the original
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Weekly plan 9
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Spend some time on terminology such as: decarboxylated; dehydrogenated; dehydrogenase; decarboxylase; and phosphorylation.
It is worth reinforcing the relationship between proton concentration and pH.
Distinguish between the structure and composition of ethanal and ethanol.
Notes
The web links referred to here are some that the author has found personally helpful but are not intended to be a comprehensive list, many other
good resources exist.
© Pearson Education Ltd 2009
This document may have been altered from the original
4