guard cell
Stomatal aperture regulator
Guard cells are specialized plant cells that occur in pairs flanking each stoma—the tiny pores in leaf surfaces through which gases and water vapor pass.
By swelling or shrinking, guard cells open and close the stomata, regulating gas exchange and water loss.
Their kidney-shaped structure allows them to bow apart when turgid, creating the pore opening.
Body or leaf opening
- stomataMicroscopic plant pores
- poreTiny dermal opening
- apertureAdjustable optical inlet
- epidermisOutermost tissue layer
chloroplast · vacuole · cytoplasm · kidney-shaped · cuticle · cellulose · inner wall · outer wall
Cellular fluid pressure
- osmosisSolvent crossing semipermeable barrier
- potassiumNineteenth element, symbol K
- openingGap or start
- closingFinal stage of something
swelling · shrinking · turgid · flaccid · malate · sucrose · aquaporins · ATP
Botanical water vapor release
- water vaporH₂O in gaseous state
- carbon dioxideRespiration byproduct, photosynthesis fuel
- oxygenElement eight, colorless gas
- diffusionPassive molecular spreading
stomatal conductance · evaporation · vapor pressure · boundary layer
Light-harvesting cell structure
- chlorophyllLight-harvesting plant pigment
- glucosePrimary cellular fuel
- starchComplex plant carbohydrate
- mesophyllPhotosynthetic tissue in leaves
Lawyers' professional body
- circadian rhythmBuilt-in sleep-wake cycle
- environmental cuesStimuli from one's surroundings
- blue lightHigh-energy visible radiation
- red lightTraffic control meaning halt
stoma
Body or leaf opening
epidermis · chloroplast · vacuole · cytoplasm · kidney-shaped · cuticle · cellulose · inner wall · outer wall
turgor
Cellular fluid pressure
- osmosisSolvent crossing semipermeable barrier
- potassiumNineteenth element, symbol K
- openingGap or start
closing · swelling · shrinking · turgid · flaccid · malate · sucrose · aquaporins · ATP · osmotic pressure
transpiration
Botanical water vapor release
- water vaporH₂O in gaseous state
- carbon dioxideRespiration byproduct, photosynthesis fuel
- oxygenElement eight, colorless gas
diffusion · stomatal conductance · evaporation · vapor pressure · boundary layer
chloroplast
Light-harvesting cell structure
- chlorophyllLight-harvesting plant pigment
- glucosePrimary cellular fuel
- starchComplex plant carbohydrate
ABA
Lawyers' professional body
- circadian rhythmBuilt-in sleep-wake cycle
- environmental cuesStimuli from one's surroundings
- blue lightHigh-energy visible radiation