4.2.1Unit 4: Energy, Environment, Microbiology and Immunity
Plant-Based Products for Sustainability — IAL Edexcel Linear Revision Notes & Topical Questions
5 min read 4 parts Lesson 14 of 28 Unit quiz
Curriculum Equation Key قوانين الرقم الهيدروجيني والاتزان الأيوني - pH & Acid-Base Equilibrium FormulasFast Exam Solution
pH = -log[H⁺] | pOH = -log[OH⁻] | pH + pOH = 14 | [H⁺][OH⁻] = 10⁻¹⁴
Word Equation & Conditions: الرقم الهيدروجيني = -لوغاريتم تركيز أيون الهيدروجين | pH + pOH = 14
Location & Specifications: الاتزان الأيوني، كيمياء 3 ثانوي، التحصيلي، و AP Chemistry.
Part 1 of 4Sustainability
Sustainability means meeting present needs without using up resources that future generations will need.
Sustainability
Renewable resource
- Renewable resource A resource such as solar energy or a replanted crop that can be used without running out.
Non-renewable resource
- Non-renewable resource Fossil fuels form over millions of years, so they can be used up faster than they are replaced.
Sustainable practice
- Sustainable practice An action that limits damage to the environment, such as replanting trees after logging.
Unsustainable practice
- Unsustainable practice An action limited by a finite supply, such as making plastics from oil.
Part 2 of 4Plant Fibres and Starch
Plants can replace oil as the raw material for many everyday products.
Fibres versus plastic
- Fibres versus plastic Ropes and cloth from plant fibres use fewer fossil fuels, and the plants can be regrown for the next generation.
Biodegradable
- Biodegradable Plant fibres can be broken down by microbes, which reduces environmental pollution compared with most oil-based plastics.
Cost
- Cost Growing and processing plants is easier and cheaper than extracting and refining oil, which helps developing countries.
Limitation
- Limitation Ropes made from plant fibres are typically not as strong as plastic ones.
Starch uses
- Starch uses Starch can be made into bioplastics or fermented to bioethanol, a fuel that is more sustainable than oil-based fuel.
Part 3 of 4Bioplastics
Bioplastics are made from biological polymers such as starch and cellulose, and several types are in use.
1
Cellulose-based plastics are made from wood pulp and are mainly used as food wrappers, for example cellophane.
2
Thermoplastic starch is mixed with other compounds such as gelatine and is used to make easy-to-swallow drug capsules.
3
Polylactic acid is made from maize or sugar cane and has properties similar to polyethene.
4
Poly-3-hydroxybutyrate is made from sugar industry products and is used in ropes, bank notes and car parts.
5
Challenges include higher cost, properties not always matching oil-based plastics, and controversy over using food crops for plastics.
Part 4 of 4Exam Checklist & Tips
4.2.1 – Key Points for the Exam
- Sustainability Using resources so that the needs of the present are met without harming future supply.
- Renewable A resource that is replaced as fast as it is used.
- Biodegradable Able to be broken down by microorganisms.
- Bioplastic A plastic made from biological polymers such as starch or cellulose.
- Bioethanol A fuel made by fermenting plant sugars or starch.
Common Mistakes
- Saying bioplastics are always better than oil-based plastics, without mentioning cost, properties and land use.
- Describing biodegradable as the same as renewable;
- biodegradable means broken down by microbes, renewable means can be replaced.
- Stating that plants fibres are stronger than oil-based plastic fibres, when they are usually weaker.
- Forgetting the food-crop issue when evaluating the use of starch from crops for plastics or fuel.
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