IGCSE Edexcel - Plant Physiology

Terms	Definitions
Tanglin Trust School
Photosynthesis	6CO2 + 6H2O → C6H12O6 + 6O2
Palisade mesophyll	Tissue in the leaves that contain many chloroplasts and are the main site of photosynthesis
Stomata	A hole in the epidermis of the leaves that allows for gas exchange to occur
Guard Cells	Cells which control the opening and closing of the stomata
Xylem	Plant tissue that transports water and minerals from the roots to the leaves / flowers
Phloem	Plant tissue that transports sugars and amino acids
Active transport	A process where energy is used to transport molecules from areas of low concentration to areas of high concentration through membrane proteins
Limiting Factor	A factor that is in the shortest supply and hence stops the rate of reaction from being any higher
Magnesium	Used to make chlorophyll
Nitrate	Used to make proteins
Phosphate	Used in photosynthesis and respiration
Osmosis	The movement of water molecules from areas of high concentration (higher water potential) to areas of low concentration (lower water potential) across a partially permeable membrane
Hypertonic	A solution with a lower concentration of water (water potential) than the cell
Hypotonic	A solution with a higher concentration of water (water potential) than the cell
Isotonic	A solution with the same concentration of water (water potential) as the cell
Turgid	A plant cell that is full of water
Plasmolyzed	A plant cell that has lost so much water that the cell membrane has shrunk away from the cell wall
Transpiration	Loss of water via evaporation and diffusion of water vapour out of the leaves
Concentration gradient	The difference in concentrations between one area and another