Plant Nutrition IGCSE

photosynthesis (word equation)

water + carbon dioxide (+ light energy) --> oxygen + glucose

photosynthesis (balanced chemical equation)

6H2O + 6CO2 --> C6H12O6 + 6O2

photosynthesis (definition)

the process by which plants manufacture carbohydrates from raw materials using energy from light

starch

excess glucose is stored in leaves in the form of this polymer

chlorophyll

a green chemical found in some plant cells (especially palisade cells) which is able to capture light energy

light intensity

the strength of light - a limiting factor in photosynthesis

carbon dioxide

a gas made of two oxygen and one carbon atom - a limiting factor in photosynthesis

chloroplast

the organelle in some plant cells which are the site of photosynthesis - contain chlorophyll

limiting factor

something present in the environment in such short supply that it restricts life processes - e.g. in photosynthesis = carbon dioxide concentration, light intensity, temperature, water supply

cuticle

the waxy layer on the surfaces of leaves to protect and prevent water loss from epidermis cells

epidermis cells

upper and lower the cells at the top and bottom of a leaf

palisade mesophyll

the layer of a leaf with closely packed cells - where most of the photosynthesis takes place

spongy mesophyll

the layer of a leaf with gaps between cells to allow for gaseous exchange and evaporation

stomata

the whole in the underside of leaves formed by opened guard cells allows for gaseous exchange of oxygen and carbon dioxide with surroundings, and water loss (transpiration)

transpiration

the loss of water from leaves through the stomata

xylem

the vessel which transports water and minerals in a plant

fluid travels upwards towards leaves

dead hollow cells

thickened with lignin (and so give support to the plant)

phloem

the vessel which transports dissolves foods (glucose) in a plant

transport food products away from the leaves to all parts of the plant

living tissue with reduced cytoplasm and seive plates

have companion cells to help with translocation

stem

supports the plant

leaf

adapted to make food for the plant by carrying out photosynthesis

roots

anchors the plant firmly in the ground

absorbs water and minerals from the soil

root hairs give a large surface area

root hair cells

a cell adapted to absorb water and minerals from the soil - root hairs provide a large surface area

vein

the vascular bundle in a leaf

air spaces

allow gases to move to and from the site of photosynthesis

nitrate ions

NO3

soluble ions required for the production of proteins in plants

magnesium

a mineral required for making chlorophyll (and so essential for photosynthesis)

found in the soil as ions

nitrogen

the most important plant mineral

used for making leaves

found as soluble nitrate ions

vascular bundle

contain the tubes which transport substances to every tissue and organ in a plant