• Student practical 9.3.3- The effect of temperature on fermentation
DO THIS NOW…
Think about aerobic and anaerobic
respiration then answer the questions
below. Explain your answers.
1. Which of the two runners is more
likely to rely on anaerobic energy
and why?
2. How would a runner ensure his
body is given a steady supply of
oxygen?
3. Does a marathon runner sprint?
Learning Objectives
Understand some applications of fermentation
Success Criteria
K- state what is meant by fermentation. name the organism used to make bread, beer, and wine.
make observations about the rising of bread dough in an investigation.
A- write the word equation for fermentation. describe how bread, beer, and wine are made. carry
out an investigation to investigate the effect of temperature on fermentation, recording
measurements and drawing a conclusion.
E- explain how the process of fermentation works in relation to the word equation. explain why
temperature is important in the making of bread, beer, and wine. carry out an investigation to
investigate the effect of temperature on fermentation, using results to draw a conclusion, and
suggest one way to minimise error.
Key terms- biotechnology, fermentation
Equipment out, date and title underlined, key terms written down
Think, pair, share…
What links these foods & drink?
This
Photo
by
Unkno
wn
Author
is
license
d
under
CC BYNC
This Photo by
Unknown Author is
licensed under CC
BY
This Photo by Unknown Author is licensed
under CC BY
New information- biotechnology
Many of the foods and drinks we consume have been made
using microbes. For example, yeast is added to bread to make
it rise. The first recording of this is by Ancient Egyptian bakers in
300BC but it was probably discovered long before this.
Biotechnology is the use of
biological process or
organisms to create useful
products. Many of these
products are food and drinks.
Demonstrate understanding
Task: State what is meant by the
term biotechnology.
The term biotechnology means when we
make use of biological processes or
organisms to create useful products like
foods or drinks.
New information- Yeast
This
Photo by
Unknown
Author is
licensed
under
CC BYNC-ND
Yeast is a microorganism that
reproduces and ferments sugar
rapidly. It is used in the production of
bread and many alcoholic drinks.
Can you remember the word equation for fermentation (a
type of anaerobic respiration) from last lesson?
Glucose à ethanol + carbon dioxide (+energy)
The alcohol in
wines, beers
and spirits.
Enzymes present in the yeast speed
up fermentation, what temperature
do you think they work best at?
The gas is trapped
as bubbles inside
the dough.
New information- Baking bread
Flour, water, and yeast are mixed to make dough. The dough is
then left in a warm place to rise. The carbon dioxide produced
during the fermentation is trapped inside the dough, making it rise.
The dough is then baked. In
the high temperatures of the
over, the ethanol evaporates.
The bubbles of gas expand,
making the bread rise further.
Demonstrate understanding
Task: Some types of bread are made without using
yeast. Suggest and explain how these breads would
differ in appearance from bread made with yeast.
Bread made without yeast will be flatter in
appearance and will not contain air bubbles. This
is because fermentation will not have occurred,
so carbon dioxide is not made. This means that
the bread will not rise.
Practical activity- The effect of temperature on fermentation
Task: Investigate the effect of increasing temperature on the
volume of bread dough. The hypothesis is the amount of carbon
dioxide produced depends on the temperature.
For this investigation what is the• Independent variable? Temperature
• Dependent variable? Volume of dough
How can you ensure it is a fair test? (control variable)
Design a suitable results table to record your data.
Include columns for the time (in minutes) and for the
volume (in cm3) of the bread dough.
Think, pair, share…
How are beer and wine made?
New information- Brewing
Beer and wine are made in very similar ways. When
they are being made, air is kept out of the juice
mixture to make sure it ferments.
The type of alcoholic drink produced depends on
the source of the sugar. This determines the type of
ethanol produced.
Wine is made
when yeast is
used to
ferment
grape sugar.
This is
known as
brewing
Beer or lager is
made when
yeast is used to
ferment sugar in
malted barley.
New information- Brewing
Plant sugar is
added to a large
container- often
the plant needs
to be crushed.
Yeast is added to
ferment the
sugar into
alcohol.
The container is
sealed to keep
out oxygen and
other microbes.
The mixture is left
until the sugar
has fermented
into alcohol.
Sediment is
removed from
the liquid, often
by filtration.
The liquid is
bottled or put
into barrels,
ready for use.
Demonstrate understanding
Task:
Cider
is an alcoholic drink
Apples
are squeezed/crushed
(to made
releasefrom
the
apples.
Explain
how The
cider
could be
produced.
juice).
Yeast
is added.
container
with
the juice
and yeast is sealed. This keeps out oxygen and
microorganisms. Yeast ferments the sugar in the
apple juice. The mixture is left until the sugar has
fermented into alcohol/cider. Sediment is removed
from the liquid (by filtration). The liquid is bottled
or put into barrels.
Review and reflect
Review: Write down…
things you have learned today
things you would like to learn more about
question you have
Reflect:
How do you feel about today’s learning?
Which objective did you reach?
What skills do you do well?
What could you do to reach the next objective?
How could you strengthen your learning at home?
Make a note of any area you need to improve…
Aiming for…
K- state what is meant by fermentation.
name the organism used to make bread,
beer, and wine. make observations about
the rising of bread dough in an
investigation.
A- write the word equation for
fermentation. describe how bread, beer,
and wine are made. carry out an
investigation to investigate the effect of
temperature on fermentation, recording
measurements and drawing a conclusion.
E- explain how the process of fermentation
works in relation to the word equation.
explain why temperature is important in the
making of bread, beer, and wine. carry out
an investigation to investigate the effect of
temperature on fermentation, using results
to draw a conclusion, and suggest one way
to minimise error.