Plant-Based Products and Sustainability

Plant-Based Products for Sustainability

• Sustainability means using resources to meet current needs without depleting them for future generations.
• This requires the use of renewable resources.
• Solar energy is a renewable resource.
• Fossil fuels are non-renewable because they take millions of years to form.
• Sustainable practices minimize environmental damage to ensure resources for future generations.
• An example of a sustainable practice is replanting trees after logging.
• Unsustainable practices are limited by a finite supply of resources.
• An example of an unsustainable practice is using fossil fuels to make oil-based plastics.

Plant Fibres and Sustainability

• Using plant fibres is more sustainable than using oil-based plastics for products such as ropes and fabric.
• Less fossil fuels are used when using plant fibres, and plants can be replanted.
• Plant fibres are biodegradable, unlike most oil-based plastics.
• This means the products can be broken down by microbes, minimizing environmental pollution.
• Extracting and processing oil is expensive and difficult, whereas growing and processing plants is generally easier and cheaper in developing countries.
• Plant fibre ropes aren't typically as strong as plastic ones.

Starch and Sustainability

• Plants store excess sugars as starch in their cells.
• Starch can be used to make bioplastics, which is more sustainable than making oil-based plastics.
• Bioplastics require less fossil fuels and can be replanted.
• Starch can also be used to make bioethanol as a fuel for vehicles.
• Using starch to produce biofuels is more sustainable than producing them from oil.

Bioplastics

• Bioplastics are made from biological polymers, such as starch and cellulose.
• Using the bioplastics offers many advantages as a replacement for traditional plastics
• Starch and cellulose are plant-based materials that can be replaced at a sustainable rate, unlike oil-based plastics from non-renewable fossil fuels
• As bioplastics are made from biological material, they are biodegradable unlike oil-based plastics
• Using bioplastics could decrease plastic pollution.
• There are multiple types of bioplastics in use:
• Cellulose-based plastics are made from wood pulp and are mainly used as food wrappers (e.g. cellophane).
• Thermoplastic starch is a mixture of starch and other compounds, such as gelatin, to create a smooth and shiny plastic
• This has been used with great success in the pharmaceutical industry to create easy to swallow capsules that contain drugs
• Polylactic acid (PLA) produced from maize or sugar cane and have properties similar to polyethene
• Poly-3-hydroxybutyrate (PHB) which is made from products of the sugar industry and used in ropes, bank notes and car parts
• Burning bioplastics, once they are no longer used prevents methane during decomposition.
• Methane is a more potent greenhouse gas than the carbon dioxide released during combustion.
• The energy released during burning can be used to generate electricity and produce more bioplastics.
• There are several challenges concerning the use of bioplastic.
• The properties of bioplastics aren't as useful as oil based plastics
• Bioplastics are more expensive than oil based plastics.
• Using limited food crops to produce plastics is controversial in some parts of the world.

Roles of Water & Ions in Plants

• Plant cells perform variety of different functions
• Plants require water and minerals to perform functions efficiently.
• Water and minerals are absorbed through root hairs and travel up via xylem vessels.
• Deficiencies in water or minerals will result in symptoms such as yellow leaves and stunted growth.

Water

• Is important for photosynthesis
• Acts as a transport medium for minerals
• Maintains turgidity in plant cells though pressure in cell vacuoles
• Regulates temperature to ensure that enzymes can function at their optimum tolerances.

Magnesium Ions

• Is an important requirement for the production of chlorophyll.
• Chlorophyll provides the green color of stems and leaves and is essential for photosynthesis.

Nitrate Ions

• Without it, the plant cannot synthesise DNA, proteins, and chlorophyll.
• Enzymes are important proteins for which nitrate ions are needed.
• These molecules are essential for plant growth, as well as the production of fruit and seeds.

Calcium Ions

• Form important cell wall components.
• Required for proper growth.

Determining the Tensile Strength of Plant Fibres

• The tensile strength of a fibre refers to the maximum load it can carry before breaking.
• For example, this information would be important when determining the strength of a rope made of plant fibres.

Required materials

• Plant fibres
• Retort stand (clamp stand)
• Clamp
• Weights

Method

1. Attach the fibre to a clamp stand.
2. Attach a weight on the other end of the plant fibre.
3. Carefully continue to add one weight at a time until the fibre breaks.
4. Record the mass at which the fibre broke.
5. This represents the tensile strength.
6. Repeat this process with more samples of the same plant fibre to increase the accuracy of your results.
7. Use these values to calculate the mean tensile strength for the fibre.
8. It is important to ensure that the fibres are all of the same length and that all other variables are kept constant.