plant structures and their functions

• Stomata are small openings on the underside of leaves, surrounded by guard cells that control gas exchange between the leaf and atmosphere.
• Guard cells regulate the opening and closing of stomata based on environmental conditions such as light intensity, humidity, and temperature.
• Xylem transports water and minerals upwards through the stem and roots.
• Root hairs increase surface area for absorption of nutrients from soil.
• Phloem transports sugars downwards from the leaves to other parts of the plant.
• Leaves contain chloroplasts which carry out photosynthesis to produce glucose using sunlight energy.
• photosynthesis is an endothermic reaction (it absorbs energy from sunlight)
• photosynthesis requires glucose, CO2 and H2O which releases O2 as a waste product
• plants are producers as they make their own food and are at the start of the food chain
• photosynthesis= CO2 + H2O --> C6 H12 O6 (glucose) + O2
• CO2 is diffused into the leaf by stomata
• Water is absorbed by the roots and goes into the xylem to the leaves
• glucose is used in respiration to release energy for the plant
• O2 diffuses out of the leaf through the stomata
• chloroplast produces chlorophyll
• balanced photosynthesis equation: 6 co2 + 6 H2o --> C6 h12 O6 + 6o2
• photosynthesis limiting factors

  temperature light intensity CO2 concentration
• temperature limiting factor

  high temperatures denature enzymes changing the active site so no substrates can bind reducing rate of photosynthesis
• limiting factors of light intensity

  more light means increases rate of photosynthesis reaching a constant
• CO2 limiting factor

  high concentration of co2 increases rate of reaction until it reaches a constant
• chlorophyll absorbs light energy
• Root hairs increase the surface area to volume ratio and absorb mineral ions by active transport which requires energy
• water moves into the root hair cell through osmosis