Biology 🌿🪴☘️

• Excess glucose is stored as starch, an insoluble storage molecule.
• Plants can produce cellulose, a strong polymer which strengthens the cell wall.
• Plants can produce amino acids which synthesise proteins.
• For plants to produce amino acids, they must absorb nitrate ions.
• Glucose releases energy in respiration, which takes place in the mitochondria.
• Excess glucose can be converted into fats & oils, which are used as a storage form of energy.
• Cell Component: Cell Membrane controls what enters & exits a cell.
• Mitochondria: Where most energy is released during respiration.
• Cell Wall: Gives structure / support to cells, made of cellulose.
• Cytoplasm: Where most chemical reactions occur.
• Nucleus: Contains genetic information about chromosomes, controls a cell.
• Vacuole: Contains cell sap, acts as a storage space.
• Chloroplasts: Contain chlorophyll, absorb light for photosynthesis.
• Ribosomes: All proteins are synthesised here.
• Photosynthesis: carbon dioxide + water → glucose + oxygen
• Sunlight is captured in the leaves’ chloroplasts.
• Water enters through a plants roots and goes up the stem through xylem cells.
• Carbon dioxide enters through the stomata.
• Guard cells control the opening & closing of the stomata.
• Each hole is a single stoma.
• The further the distance from the light source, the less oxygen bubbles appear.
• This shows that less oxygen is released and that the rate of photosynthesis decreases when there is a limiting factor involved.
• Aerobic Respiration: glucose + oxygen → carbon dioxide + water
• In nutrient poor soils, nitrogen and other minerals are difficult to absorb.
• Palisade (mesophyll) cells: At the top of a plant since they are specialised for trapping light, packed with chlorophyll
• Stomata: Open up so that CO2 can diffuse into the leaf, controlled by guard cells
• Spongy (mesophyll) cells: An airy layer of cells, far apart so CO2 can enter easily
• Epidermis (upper & lower) cells: Produce a waxy layer called the cuticle
• Cuticle: Seals up the leaf so the only way in and out is through the stomata
• Chloroplasts: Vertical to allow space for maximise sunlight absorption
• Most leaves have a large surface area so they can trap as much sunlight as possible
• They are also quite thin so that CO2 doesn’t have very far to travel.
• Fertilisers are used to improve plant growth and include a concentrated form of mineral salts (potassium, phosphates, nitrates).
• Manure is a natural fertiliser.
• Herbicides kill weeds which compete with crops.
• Plants produce many different lipids, including the cuticle of a leaf which makes it waterproof.
• Insecticides and pesticides kill pests which reduce the yield.
• Seeds contain a store of all the resources a new seedling will need to grow.
• Selective breeding is when certain plants are chosen to breed together so the product can have certain characteristics.
• Advantageous Characteristics are characteristics which make insects more likely to survive, if they are more likely to survive, they are more likely to breed and thus pass on the gene for the advantageous characteristic(s).