Edexcel A Level (IAL) Biology -4.7 Plant-Based Products for Sustainability- Study Notes- New Syllabus
Edexcel A Level (IAL) Biology -4.7 Plant-Based Products for Sustainability- Study Notes- New syllabus
Edexcel A Level (IAL) Biology -4.7 Plant-Based Products for Sustainability- Study Notes -Edexcel A level Biology – per latest Syllabus.
Key Concepts:
- 4.7 understand how the uses of plant fibres and starch may contribute to sustainability, including plant-based products to replace oil-based plastics
Uses of Plant Fibres & Starch in Sustainability
🌱 Introduction
Modern industries often depend on oil-based materials (like plastics and nylon). However, these are non-renewable, non-biodegradable, and harm the environment.
Plants provide a sustainable alternative through natural fibres and starch-based materials.
By using plant fibres and starch, we can reduce pollution, save fossil fuels, and move toward eco-friendly living.
🪶 1. Plant Fibres – Structure & Role
Plant fibres are mainly made of cellulose, giving them high tensile strength and durability. They are obtained from sclerenchyma and xylem tissues in plants.
Common Sources:
- Cotton – from seed hairs
- Flax & Jute – from stem fibres
- Hemp – from bast fibres of the stem
- Coir – from coconut husk
Properties of Plant Fibres:
| Property | Description |
|---|---|
| Strong & Flexible | Cellulose microfibrils arranged in parallel give strength |
| Lightweight | Easier to handle & transport |
| Biodegradable | Breaks down naturally → reduces pollution |
| Renewable | Plants can be regrown easily |
| Water-absorbent | Useful for certain industrial materials |
🧺 2. Sustainable Uses of Plant Fibres
| Use | Plant Fibre Example | How It Improves Sustainability |
|---|---|---|
| Textiles & Clothing | Cotton, hemp, flax | Replace polyester/nylon fabrics (oil-based) |
| Ropes & Cables | Jute, coir | Biodegradable replacements for nylon ropes |
| Paper & Packaging | Bamboo, hemp | Reduces plastic packaging waste |
| Composite Materials | Flax, jute + resin | Used in car interiors, furniture, construction – lightweight & renewable |
| Bioplastics Reinforcement | Jute, sisal | Fibre-reinforced plastics that are partly plant-based |
Memory Tip: “Fibre Fixes Fossil Problems” – natural fibres help cut down oil dependence.
🌽 3. Plant Starch – Structure & Source
Starch is a polysaccharide made of glucose. Plants store starch in grains (e.g., potatoes, maize, wheat, cassava).
Properties:
- Renewable & biodegradable
- Can be chemically modified to form bioplastics
- Can be converted into bioethanol (renewable fuel)
🧴 4. Uses of Plant Starch in Sustainability
| Application | Description | Sustainability Benefit |
|---|---|---|
| Bioplastics (starch-based polymers) | Starch is modified into materials like PLA (polylactic acid) | Replace oil-based plastics → biodegradable |
| Packaging materials | Starch foam used for packing chips, boxes, trays | Replaces polystyrene (non-biodegradable) |
| Biofuel (Bioethanol) | Starch fermented by yeast → ethanol | Renewable, lower CO₂ emissions |
| Adhesives & coatings | Used in paper, card, and fabric coatings | Non-toxic, plant-based alternative |
Example: “Corn starch bioplastic bags” look like plastic but degrade naturally — used in supermarkets as compostable bags.
🌏 5. Why This Supports Sustainability
| Reason | Explanation |
|---|---|
| Renewable resource | Plants can be regrown every season |
| Biodegradable | Decompose naturally without harming soil or water |
| Reduced fossil fuel use | Less dependency on oil-based raw materials |
| Lower carbon footprint | Carbon absorbed during plant growth offsets emissions |
| Less pollution | No microplastic release into oceans |
🧠 6. Limitations to Consider
- Large-scale farming may compete with food production.
- Some bioplastics still require industrial composting to break down.
- More research needed to make them as durable as oil-based plastics.
🌿 7. Summary Table
| Aspect | Plant Fibres | Plant Starch |
|---|---|---|
| Main Component | Cellulose | Amylose + Amylopectin |
| Source | Stem, leaf, or seed tissue | Storage organs (grains, tubers) |
| Main Use | Ropes, textiles, composites | Bioplastics, biofuel, packaging |
| Eco Advantage | Strong, renewable, biodegradable | Renewable, biodegradable, carbon-neutral |
| Replaces | Synthetic fibres, nylon | Oil-based plastics, fuels |
⚡ Quick Recap:
Plant fibres → Strong, renewable → replace synthetic textiles.
Plant starch → Converted into bioplastics or biofuel.
Both are biodegradable → reduce plastic pollution.
Help sustainability by reducing:
– Oil usage
– Greenhouse gases
– Plastic waste
🧠 Mnemonic: F.S.E. – Fibres, Starch, Environment → “From plants to save the planet!”