Topic 4: Starch and sustainability Flashcards
Define sustainability (2 points - 1 general definition, 1 definition in terms of resources for humans)
- The ability to MAINTAIN A BALANCE OF A PROCESS in a system
- Using resources to meet the needs of the present generation, whilst preserving resources for future generations.
How can humans be sustainable with their materials?
2 points
- use RENEWABLE RESOURCES of materials
2. use materials and methods which MINIMISE HARM TO {BIODIVERSITY / THE ENVIRONMENT}.
For humans to live sustainably, the Earth’s resources must be replenished at the ____ ____ at which they are used.
same rate
Define sustainable (2 points)
A resources that can be renewed,
so will not run out and is therefore available for future generations.
Define biodegradable (2 points)
Something that:
- Will decompose and not accumulate
- Will not contribute to landfill
Define ecological footprint
1 point
The area of land you would require to support your current lifestyle.
List 5 human activities that have negative impacts
any 5 from the list
Deforestation Pollution Over-hunting/fishing Illegal pet trade Ozone depletion Global warming Wasting electricity Replacing working products eg. mobile phones, TVs Over-use of cars
List 5 human activities that have positive impacts
any 5 from the list
Recycling waste, clothes etc Reusing/upcycling Make do and mend Tree planting and habitat regeneration Quotas/bans (eg. on whaling) Conservation initiatives Banning CFCs Fair trade products and ethical purchasing Waking, cycling, car sharing
List 5 things an individual could do to help the environment
any 5 from the list
Recycle old clothes and buy from charity shops
Cycle, walk or take {bus/train} – rather than driving
Don’t replace electronic devices (eg. mobile phones) that work, just to get the ‘latest model’
Buy a refillable {water bottle/coffee cup} to reuse
Recycle plastics and drinks cans
Don’t buy so much food, that a lot gets wasted
Buy fair trade chocolate, coffee etc.
Eat sustainable fish
Don’t use plastic bags, food bags etc.
Key Summary: Why are products made from crude oil/plastic OR petrol/diesel (from crude oil) not sustainable?
(5 points)
- Crude oil is a FOSSIL FUEL, so is non-renewable OR {plastic/petrol/diesel} COMES FROM crude oil which is a fossil fuel, so is NON-RENEWABLE
- Crude oil WILL RUN OUT, so will NOT BE AVAILABLE FOR FUTURE GENERATIONS
- Burning fossil fuels releases CO2 which contributes to Global Warming
- Plastics may BIODEGRADE, decompose MORE SLOWLY – so will CONTRIBUTE TO LANDFILL
- Plastics made from crude oil generate NON-BIODEGRADABLE WASTE
Explain how the use of plant-based products can contribute to sustainability (3 points)
Examples of plant-based products: plant based plastics, starch bags, canvas bags, biodiesel
- LESS FOSSIL FUELS are used up, so will last longer/be available for future generations
- {Crops/trees/plants} CAN BE RE-GROWN – they are RENEWABLE to maintain supply for future generations
- Plant based products are BIODEGRADABLE (decomposed by microbes) so don’t contribute to landfill
Key Summary: Explain why a product made from starch/plants/jute fibres/bioplastic is sustainable
(3 points)
- Made from plants OR comes from PLANTS - which are a renewable resource which will not run out
- More PLANTS can be grown to REPLACE THOSE USED, so will be available for future generations
- Biodegrade, decompose MORE QUICKLY – so will not contribute to landfill
Plant fibres can be added to other materials to form ______________.
What are the advantages of ______________? (3 advantages)
NOTE: both “______________” are the same
biocomposites
eg. oilseed rape fibres and plastic are combined to make a material stronger than plastic alone
1. Renewable
2. More biodegradable
3. Easier and safer to handle than artificial composites
Mats of plant fibres ABSORB _______ _______ and ____________ from polluted water
What is the advantage of this?
(1 advantage)
heavy metals
hydrocarbons
- Avoids the use of chemicals
Plant-based plastics or bio-plastics have been developed using renewable plant biomass sources from the __________ of sugars from wheat, sugar beet, potatoes, vegetable fats, corn starch, pea starch or agricultural waste.
fermentation
How can plastic bags be replaced?
2 points
- Use bags made of canvas, cotton, linen or jute that can be reused
and are biodegradable at the end of their life - Use bags made of plant based plastic
How can plastic packaging be replaced?
2 points
- Buy loose fruit and veg at the supermarket and
take your own reusable bags to put fruit and veg in - Take containers to put meat and fish in from the {counter/butcher}
Carbohydrate polymers (starch) and oils from seeds have many important industrial uses.
List them
(5 uses)
- Thickening
- Stiffening
- Super absorbents
- Starch foam
- Starch based plastics
Starch is easily extracted – starch granules do not _______ in water and can be washed out of seeds
dissolve
Explain “Thickening” of starch
3 points
- Heating starch granules in water,
- they swell, absorb water, and thicken liquid.
- This is called ‘gelatinisation’
Explain “Stiffening” of starch
5 points
- Starch mixture is applied to {fabric/paper},
- then gelatinised,
- then cooled.
- Bonds form between starch molecules
- This is called “sizing”.
How can the stiffening of starch be reversed? (1 point)
What is this process called? (1 point)
- By adding water (the material becomes flexible again)
2. Plasticisation
Explain how “Super Absorbents” made from starch
4 points
- Starch is chemically cross-linked,
- then gelatinised.
- This forms particles which are dried.
- Particles can absorb large amounts of water.
e. g. Cross-linked starch is found in super-absorbent nappies
Explain how “Starch foam” is made from starch
4 points
- Starch granule containing very little water is put under pressure in a starch extruder, which is a machine that applies pressure,
- heating takes place and pressure builds up.
- Pressure is suddenly released (eg. seed coat ruptures during cooking to make popcorn).
- Steam forms, so starch ‘puffs’ into an expanded structure.
NOTE: Starch foam is used in pop corn, packing foam, puffed cereals etc…
Seeds are a rich source of ____ used for cooking and also ____.
________ can be used in unmodified diesel engines alternating with petroleum diesel (produces less ________ _______ and ________ _______ than diesel).
oils
fuel
Biodiesel
sulphur dioxide
carbon dioxide
What can biodiesel be made from? (2 things)
- Waste vegetable cooking oil
2. Oil crops (e.g. rapeseed oil)
Give 3 examples of what starch is used in
any 3 from the list
custard powder, wallpaper paste, nappies, packaging foam, adhesives, paints, textiles, plaster, insulation, toiletries i.e. shampoo, mousses, sunscreens & anti-perspirants
Give 2 examples of what oils are used in
2 examples
- Cooking oil (e.g. sunflower oil)
2. biofuels
In terms of sustainability, what needs to be considered about plant based products? (2 things)
- the SOURCE of the plant product and whether land has been cleared of trees to be used for growing the plant crop
e. g. reduced biodiversity due to palm oil plantations for biodiesel - the {ENERGY/FUEL} USED and POLLUTION created during PRODUCTION and TRANSPORT of product
What should be considered about a sustainable resource to determine its advantages and disadvantages? (7 points)
NOTE: Do not list adv/disadv. just list what needs to be considered.
- {How carbon neutral it is/how well crop removes carbon dioxide from atmosphere (by photosynthesis) as plant grows} + link to {greenhouse effect / global warming}
- How much {water/fertilisers/pesticides} the crop requires and effect of fertilisers on the ecosystem
- Which fuel is used to transport the {crop/resource}
- What else the land could be used for? eg. food production
- The low biodiversity of a monoculture
- {Production costs/support for the economy}
- Does it provide jobs for local people?
What are the key terms that should be used when answering a question about {sustainability/a sustainable product} (8 points)
- Sustainable (if not mentioned in the question)
- From a RENEWABLE RESOUCE (eg. plant), so WILL NOT RUN OUT, so AVAILABLE FOR FUTURE GENERATIONS (often compared to products from crude oil which is a non-renewable resource)
- MORE PLANTS CAN BE GROWN to replace those used
- BIODEGRADABLE – so will DECOMPOSE and NOT CONTRIBUTE TO LANDFILL
- COST – plant products may be cheaper
- STRENGTH – plant products e.g. jute ropes, may not be as strong as plastic/synthetic ones
- Using plant products will allow crude oil supplies to last longer
- Time scale – plants can be grown quickly, fossil fuels/crude oil takes millions of years to form
(NOTE: when answering a question, choose the most appropriate points)
