Sciences ‒ Fourth Level Exemplification
Significant aspect of learning
Knowledge and understanding of scientific ideas, principles and
concepts relating to biological systems.
Relevant sciences experiences and outcomes
Related experiences and outcomes
MNU 4-20
I can evaluate and interpret raw and graphical data using a
variety of methods, comment on relationships I observe within
the data and communicate my findings to others.
SCN 4-13b
I have taken part in practical activities which involve the use of
enzymes and microorganisms to develop my understanding of
their properties and their use in industries.
SCN 4-20a
I have researched developments in science and can explain
how their current or future applications might impact on
modern life.
Context for learning
This piece of learning was a biology and chemistry based topic around the subject of enzymes and their use in everyday life.
Learners completed a series of experiments investigating the function and effect of an enzyme in a chemical reaction. Evidence of
learners’ understanding was drawn from the following tasks:
• An investigation into the effect of changing conditions of pH and temperature on enzyme activity using catalase in potato discs
• An investigation into the effect of changing temperature on the production of alcohol during fermentation
• An analysis of a washing detergent label – learners were asked to highlight and explain the important details on the packaging.
Task: Investigation into the effect of changing temperature and pH on enzyme activity
Teacher note: This learner has represented the
breakdown of hydrogen peroxide as a word
equation and identified a feature of the reaction
that allows them to measure the activity of the
enzyme (production of oxygen gas).
Teacher note: The term ‘optimum conditions’ has been applied appropriately
and the learner has described the effect on the activity of an enzyme acting
outwith its optimum conditions. They have referred to the enzyme being
‘denatured’ and explained the consequences of this on enzyme activity.
Teacher note: From a graph of enzyme activity at
varying temperature and pH, this learner has
been able to identify the optimum conditions for
catalase. When questioned, the learner was also
able to identify that the enzyme had been
denatured when its activity was reduced to 0.
Learner voice: ‘I had to carefully plan a fair experiment using same size bits of potato, same concentration of Hydrogen Peroxide etc. I did
this to try and get reliable results. I also repeated my experiments to calculate an average.’
TASK: Investigation into the effect of changing temperature on the production of alcohol during fermentation.
Context and success criteria:
This learner has selected the alcoholic beverage
industry to investigate. They have used the production
of carbon dioxide gas as a measure of reaction rate
and thus enzyme activity.
They have expressed the reaction as a word equation.
The learner has appreciated that the yeast is a
microorganism that contains the necessary enzymes
for fermentation to occur.
They included a list of dependant, independent and
constant variables in their experiment plan.
Next steps:
The learner has not appreciated that there is a maximum
concentration of alcohol that can be achieved during
fermentation, rendering their conclusion that the optimum
temperature would “make the most alcohol” inaccurate
without an accompanying statement of time limit e.g.
“would make the most alcohol in the shortest time”.
Teacher note: From their results, this learner has concluded that the
largest volume of carbon dioxide implies the fastest rate of alcohol
production and therefore the higher enzyme activity. They’ve shown
they understand the fermentation equation and can evaluate the
relationship between enzyme activity and Carbon Dioxide production.
Learner voice: ‘ I had to set up my experiments in a fair way so that I could compare my results in a reliable way. This meant planning my
experiment to have constant variables e.g. the volume of water, the mass of sugar added and the type of balloon. I judged which
balloon had more as by its size. I could have removed the balloon, tied it and displaced it in water to measure the molar volume of
carbon dioxide. If I had 1 mole of carbon dioxide (44g) I would expect to have 24L of gas!’
TASK: Analysis of washing detergent label
Learners were presented with a label from a
biological washing detergent and asked to annotate,
with justifications, the important information.
Success criteria:
The learner has:
•
Identified that ‘biological’ means that the
washing powder contains enzymes
•
Identified the function of the enzymes
mentioned and suggested a function for lipase in
washing powder
•
Applied the term ‘optimum conditions’ to the
temperature described
•
Suggested that a boiling temperature may
denature the enzyme and thus reduce its
efficiency.
Learner voice:
‘I had to bring together all the vocabulary and
knowledge that I had learned in this summary task. I
was able to recognise that having the washing
machine too hot would denature the enzymes, as my
graph from the earlier experiment showed this. I can
now explain this to my mum when she has the
washing machine at a high temperature. The
temperature of 40O that the packaging recommends,
will be the optimum, meaning that this should be the
best cleaning conditions. I could set up an experiment
washing stains at different temperatures to prove
this.
Next steps:
The learner could investigate:
•
The reason why enzymatic cleaning may not be suitable for silk fibres
•
Allergic reactions associated with biological washing detergents
•
Products used to clean washing machines following a build-up of
biological material
•
The advantages and disadvantages of using biological washing
detergents in a large hotel.
Teacher comment: This learner
decided on a practical of their choice
to investigate further the use of
enzymes in washing powders. They
formulated their own method which
included accurate measurements and
also mentioned the variables needed
to be kept constant to ensure a fair
test. They have used the terms
‘independent’ and ‘dependant’
variables correctly. They have also
been able to identify how they could
improve their experiment, by using a
wider range of stains, to get more
reliable results.
Peer feedback: ‘I like how you have
included the masses and volumes
needing to be measured out. I could
follow this method to carry out the
experiment myself. Have you
considered investigating how
effective the washing powders are at
different temperatures to see if they
denature above a certain
temperature?’
Next steps:
This learner could start to explore different ways of presenting their data. By developing their ICT skills they could learn to produce
tables and graphs digitally, selecting the most appropriate format for their data.
They have also demonstrated good evaluation skills. They could look to develop analytical thinking skills, comparing graphs from
other enzymes and predicting optimum conditions for others.
This learner could continue to develop their understanding of enzymes and their uses in industry in National 5 Biology, where the
idea of optimum conditions is developed. That enzymes are proteins will also be introduced.
In National 5 Chemistry, they would develop their evaluative skills to use features of a chemical reaction to measure average
reaction rate. This may be related to enzyme activity and identifying optimum conditions.