Download Commercial uses of cells

Commercial uses of cells
Intermediate 2 Biology
Unit 1: Living Cells
Learning Objectives
• To revise knowledge on cell variety and cell
structure
• Revise the function of nucleus, cytoplasm, cell
membrane, cell wall, chloroplasts and
vacuole.
• To revise anaerobic respiration / fermentation
in yeast
• Revise the use of fungi to make antibiotics
• Revise yoghurt production
• Revise biogas and gasohol production
Cell Structure and Function
• Why is the cell described as the basic unit
of life?
• Name three structural features that a
typical plant cell and a typical animal
cell have in common.
• Name three structural features present in
an Elodea leaf cell but absent from a
cheek epithelial cell.
• Give the function of each of the following
structures: cell membrane, cell wall,
nucleus.
Commercial and Industrial Uses of Cells
• Give the word equations for aerobic and anaerobic
respiration in yeast.
• Describe the role of carbon dioxide in bread making
• Write a simple word equation to summarise the process of
malting in barley grains about to be used in the brewing
of beer.
• Copy the following sentences choosing the correct
answer from each choice in brackets:
– During the production of yoghurt, (bacteria/yeast)
respire (aerobically/anaerobically) and convert
(maltose/lactose) to (lactic acid/alcohol). This
chemical brings about the coagulation of milk
(proteins/sugars) and acts as (an antibiotic/a
preservative).
Commercial use of Microorganisms
• Microbes used commercially and in
industry are:
– Fungi
• bread making, brewing, gasohol (alternative
fuel) and antibiotics
– Bacteria
• yoghurt production and biogas (methane gas)
GASOHOL AND YEAST
• Alcohol and Gasohol are renewable fuels.
• Alcohol is produced in fermentation
• When yeast ferments sugar, alcohol is
produced, but in small amounts.
• The alcohol can be separated from the
fermentation mixture by distillation. Alcohol
is flammable and can be used as a fuel.
• If Alcohol is mixed with petrol it produces
gasohol
Gasohol Production
BIOGAS AND BACTERIA
• Some bacteria produce methane gas
in conditions where oxygen
concentrations are low.
• This gas is rich in chemical energy and
can be burned. This is biogas.
• Biogas can be produced from organic
waste and is a gas produced by
decaying rubbish
Biogas Production
Commercial and Industrial uses of cells –
YEAST SUMMARY
• Bread making
– anaerobic respiration in yeast produces
carbon dioxide which makes the dough rise.
• Alcohol production
– fermentation (anaerobic respiration) in yeast
produces alcohol. The sugar comes from
malted barley or fruit.
• Alternative fuels
– When alcohol is mixed with petrol it is gasohol
Commercial and Industrial uses of cells –
BACTERIA SUMMARY
• Yogurt production
– bacteria convert the sugar (lactose) in
milk into lactic acid. The lactic acid
causes the milk to thicken and curdle.
• Alternative fuels
– Bacteria ferment (anaerobic respiration
waste products and produce methane
gas.
– This is called Biogas
5 Mark Questions
Labelled diagrams may be included where appropriate.
• Describe how cells are used in the
production of yoghurt and alternative
fuel. Include in your answer for both,
the type of cell used, the substrates
and the products.( Int 2 2005)
• Describe the function of yeast in bread
making and the anaerobic pathway
of respiration involved in this process.
(Int 2 2008)
Question – 5 marks
• The diagram below
shows a container
used for home wine
production.
• Describe the
anaerobic pathway
of respiration which
results in wine
production in this
container.