Plant Biology Key Words Flashcards
Transpiration
The evaporation of water through the stomata in leaves
Translocation
The movement of dissolved sugars through a plant from the leaves (source) to the rest of the plant (sink) in phloem tubes
Limiting Factors
A factor which affects the rate of photosynthesis. High levels of CO2 and H2O, light intensity and temperature will increase the rates of photosynthesis.
Phloem
Cells that transports dissolved sugars (glucose or sucrose) from the leaves (source) to the rest of the plant (sink)
Transpiration Stream
The movement of water around a plant from roots (source) to the leaves (sink)
Xylem
Cells that carry water and minerals around a plant from the roots (source) to the leaves (sink)
Iodine
A chemical used to detect starch (it goes blue / black) in leaves. This proves that photosynthesis has taken place.
Glucose
The sugar made by plants during photosynthesis, used in respiration.
Starch
How a plant stores its glucose.
Photosynthesis
The process that plants use to make their food.
Water + Carbon Dioxide —> Glucose + Oxygen
6H2O + 6CO2 –> C6H12O6 + 6O2
Diffusion
The (random) movement of particles from a region of High to Low concentration until equilibrium is reached. How gases move around. No energy needed (it is a passive process).
Root hairs
Small hairs on roots that increase a root’s surface area and allow more water / minerals to be taken up.
Active transport
The movement of particles (e.g. minerals) from a region of Low to High concentration. Needs energy.
Enzymes
Catalysts that speed up reaction rates. Made of proteins
Chloroplast
Where photosynthesis takes place in cells
Chlorophyll
A green pigment which absorbs sunlight. Found in chloroplasts.
Respiration
C6H12O6 + 6O2 –> 6H2O + 6CO2 + Energy
A reaction that produces energy. The opposite reaction to photosynthesis.
Mitochondria
Where respiration takes place in cells to make energy
Producer
Plants are called this (in food chains) since they produce their own food by photosynthesising.
Leaves
Organs in plants needed for photosynthesis
Flowers
Organs in plants needed for reproduction
Osmosis
The (random) movement of water from a region of High to Low concentration until equilibrium, through a partially permeable membrane. No energy needed (it is a passive process).
Stomata
Pores / holes found in the under surface of a leaf, where gaseous exchange takes place. CO2 enters and O2 leaves.
Guard Cells
Cells found either side of stomata that open and close the stomata to change rates of water loss.
Vascular Bundle
A bundle of xylem and phloem vessels in a plant used to transport materials around a plant.
Waxy Cuticle
A waterproofing layer at the top and bottom of a leaf
Epidermal cells
Upper and lower layers of cells in a leaf
Palisade mesophyll cells
Where most photosynthesis takes place in a leaf. Found near the top of leaves (close to the light) and packed with chloroplasts.
Spongy mesophyll cells
Cells in a leaf surrounding by air spaces to allow for gaseous exchange.
