Download Banjos to biodiesel – linking products to photosynthesis Teaching

Banjos to biodiesel – linking products to photosynthesis
Teaching notes
Task 1
Working in pairs/groups, students are given all the 'structure', 'use' and 'function' words all
jumbled up together. They are asked to sort the words into three groups.
Suggested groupings:
Plant structures: bark, bulbs, corms, flowers, fruit, leaves, nuts, phloem, roots,
seeds, sprouting seeds, stems, thorns, trunk, tubers, xylem.
Uses of plants: adhesives, biofuels, bioplastics, boats, construction, cosmetics,
decorations, dyes, food, fuel, medicines, musical instruments, paper, perfumes, rope,
sports, textiles, tools, varnish.
Functions of plant cells, tissues and organs: absorption, growth, photosynthesis,
protection, reproduction, respiration, storage, support, transport.
They are asked to discuss what might be a connection between all the words.
From plants we can make all these materials as well as eating them.
Move the discussion on to what process/product is at the heart of all these things.
Photosynthesis and glucose.
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Banjos to biodiesel – linking products to photosynthesis
Task 2
Explain that they are going to decide how glucose is linked to the wide range of 'uses' by
giving examples of many of the uses:
e. g. Lavender is used in perfume.
What part of the plant is used?
Flower.
How does this link to glucose?
The plant uses glucose to make the chemicals in the perfume.
To stimulate their ideas, 6 examples are provided which give some unusual and
contemporary uses of plants.
Task 3
Groups can work on this for a few minutes before being introduced to the 'fact cards'
which provide more detailed information about certain parts of the plant.
Cellulose makes up cell walls and so relates to all parts of the plant; lignin occurs where
strength and/or water resistance is needed; plant saps are found in and around plant cells
and in xylem and phloem; plant proteins are required for growth so are found in growing
tips and seeds and are stored; plant oils and starch are stores of energy for the plant,
although fats are an essential part of cell membranes.
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Banjos to biodiesel – linking products to photosynthesis
Task 1
Cut out the keywords and sort them into three groups.
Discuss the connections between the words in each group.
leaves
reproduction
sprouting seeds
boats
dyes
bulbs
decorations
fruit
bioplastics
cosmetics
xylem
stems
photosynthesis
rope
varnish
sports
construction
biofuels
growth
fuel
bark
flowers
roots
transport
paper
trunk
tubers
phloem
seeds
protection
perfumes
thorns
storage
nuts
medicines
adhesives
textiles
respiration
support
tools
food
musical
instruments
corms
absorption
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Task 2
Plants photosynthesise to produce glucose. How is glucose linked to the wide range of
uses of plants?
Choose six plants and their uses and fill in the table below. There are some information
cards to help.
Plant
Lavender
Use
perfume
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Part of plant used
How does this link to glucose
Plant uses glucose to make the
chemicals in perfume.
flower
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Information cards – plants and their uses
Galantamine is a drug used to treat Alzheimer's
disease. It is found in plant sap in the leaves
and bulbs of daffodils and is thought to protect
the plant from grazing animals. Daffodils are
grown on farms in the Black Mountains, Wales.
10 tons of bulbs yield 1 kg of galantamine.
Daffodil
Aloe vera has been used for more than 3 000
years. It is cultivated worldwide, primarily as a
crop for "Aloe gel", which comes from the leaf.
Today, it is used in: food - as a natural
flavouring, cosmetics, food supplements and
herbal remedies.
Aloe
vera
Aloe latex contains anthraquinones, compounds
that are used in healing and reducing pain
because of their natural anti-inflammatory
effects.
A study published in General Dentistry reported
that Aloe vera in tooth gel is as effective as
toothpaste in controlling cavity-causing oral
bacteria.
The botanical name of abaca is Musa Textilis, a
tree-like herb which is of the same genus as the
common banana which it closely resembles. It is
indigenous to the Philippines.
Abaca
© Cherrie Mio Rhodes 2011
https://flic.kr/p/9zsdUp
© www.teachitscience.co.uk 2014
Car manufacturers have used a mixture of
polypropylene thermoplastic and abaca yarn in
car body parts. Production of abaca fibre from
cellulose and lignin uses an estimated 60% less
energy than production of glass fibre and is
biodegradable over time.
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Evening primrose oil is extracted from seeds of
the evening primrose plant (Oenothera biennis) a wild flower that grows in eastern and central
North America.
Originally, evening primrose was used by Native
Americans to make poultices and heal wounds.
It was also traditionally eaten and used as a leaf
vegetable.
Evening
primrose
© David Short 2011 https://flic.kr/p/acy1qT
Nowadays evening primrose is mainly used for
the production of its oil, which is commonly used
to help reduce the pains associated with
menstruation and for its therapeutic benefits for
the skin of the face.
Bamboo
Why cut down a 40 to 100 year old tree when
bamboo stems can provide one of the hardest
building materials there is and grow an average
of 50 centimetres a day? Indeed, bamboo is the
fastest growing woody plant in the world. Some
species can grow as much as 121 centimetres in
a 24-hour period. Stronger than steel, bamboo
grows like a weed and can be a very viable
building material.
Soya
bean
Soya bean oil is used to produce flexible foam.
Such foams were first used in automobile
seating, then upholstered furniture and then
mattresses and pillows. The first generation of
these foams had an odour and, unlike
petrochemicals, plant–based oils can turn rancid.
Second and third generations products have
been modified at the molecular level to produce
odourless foams.
© ricoeurian 2006 https://flic.kr/p/r5TV9
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Task 3
1.
Read the information cards about the different chemical substances that are found
in plants. Complete the table to show the structures in plants that they relate to.
Plant chemical
substance
Cellulose
2.
Part of plant substance is found in
Cell walls throughout the plant
strong
Link the uses of plants cards from Task 1 to the properties of the chemical
substances that make them suitable for what they are used for.
Plant chemical substance
3.
Properties of substance
Use of plants
Construct a mind map with ‘photosynthesis and glucose’ at the centre. It should
show the connections between chemical substances in plants, plant structures and
functions and the uses of plants.
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Information cards – substances in plants
Cellulose
The plant cell wall surrounds the cell membrane. It is made up of multiple layers of
cellulose which are arranged into primary and secondary walls. Cellulose is the most
common organic compound on Earth. About 33% of all plant matter is cellulose - the
cellulose content of cotton is 90% and wood is 50% cellulose.
Cellulose is a polymer made of repeating glucose molecules attached end to end. A
cellulose molecule may be from several hundred to over 10,000 glucose units long.
Lignin
The cell walls of all vascular plants also contain a polymer called lignin. Lignin is
water-resistant. It reinforces cell walls, keeping them from collapsing. This is
particularly important in the xylem, because the column of water in the hollow xylem
cells is under tension (negative pressure) and without the lignin reinforcement the
cells would collapse.
Lignin provides the structural strength needed by large trees to reach heights in
excess of 100 m. Without lignin these trees would collapse on themselves. Also, lignin
along with other cell wall constituents provides resistance to diseases, insects, cold
temperatures, and other stresses. Lignin plays a crucial part in conducting water in
plant stems.
Plant oils
Oils produced by plants are found in seeds, nuts and some fruits. They represent a
store of energy. Aromatic plant oils have evolved to attract insects. Vegetable oils
consist of molecules of fatty acids and glycerol and are formed from the elements
carbon, hydrogen and oxygen. These elements also make up molecules of glucose.
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Plant proteins
The glucose in the leaves reacts with nitrates and other salts to form amino acids.
These are then combined to make proteins that are used to form enzymes and
chlorophyll in the cells. Excess amino acids are either stored in the leaves or are
carried to the growing parts of the plant.
Sap
Sap is the name given to fluids found in plants. There are different types of sap e.g.
cell sap, xylem sap and phloem sap. Each contains different concentrations of
dissolved substances. Saps are involved in the transport of sugars, amino acids and
other chemical substances around the plant. Another form of sap is involved in
protecting the plant from herbivores especially herbivorous invertebrates, examples
include plant resins and latex.
Starch
Starch is the main form in which plants store carbon. It occurs as semi‐crystalline
granules composed of two polymers of glucose, called amylose and amylopectin.
Starch is insoluble in water and can act as a store of carbon for a few hours, for
example in leaves, or for many years as in dormant seeds. There is enormous
variation in granule size and shape between plant organs, and between plant species.
Starch is the major carbohydrate of nutritional importance in the diet: it is degraded
to glucose by amylases in the mouth and small intestine. When cooked in water,
starch forms gels or pastes that have a wide range of industrial applications in food
and other industries.
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