B6 plant nutrition Flashcards
define photosynthesis
- process by which plant synthesise carbohydrates from raw materials
- using energy from light
word equation for photosynthesis
carbon dioxide + water –> glucose + oxygen
in the presence of light. and chlorophyll
what is chlorophyll
- green pigment
- found in chloroplasts
balanced symbol equation for photosynthesis
6CO2 + 6H2O –> C6H12O6 + 6O2
what does chlorophyll do
- transfer energy from light into energy in chemicals
- for synthesis of carbohydrates
what is starch used for (photosynthesis)
energy store
what is cellulose used for
build cell walls
what is glucose used for (photosynthesis)
respiration to provide energy
what is sucrose used for
transport in phloem
what is nectar used for
attract insects for pollination
what are nitrate ions used for
making amino acids
what are magnesium ions used for
making chlorophyll
how does light intensity affect rate of photosynthesis
- light intensity inc, photosynthesis inc
- up to certain point, any further inc will not inc rate
how does co2 conc affect photosynthesis
- conc inc, photosynthesis inc
- up to certain point, any further inc will not inc rate
how does temp affect photosynthesis
- inc as temp inc
- up to point, then decreases
- because of denaturation of enzyme (photosynthesis is enzyme catalysed)
how does hydrocarbonate indicator solution show how light intensity affects gas exchange in aquatic plant
- dark condition: respiration > photosynthesis, orange (high conc co2)
- light condition: photosynthesis > respiration, purple (low conc)
- control: equal, red (normal atmospheric conc)
adaptations for photosynthesis
leaves have large surface area and are thin
how does large leaf surface area improve photosynthesis
- larger area exposed to sunlight & air
- easier absorption of these materials
how does thin leaf improve photosynthesis
- co2 from air diffuses quickly to photosynthetic cells
- light penetrates easily
function of cuticle
stop water from evaporating from leaf
adaptation of cuticle
waxy layer
function of chloroplast
site of photosynthesis
adaptation of chloroplast
- contain chlorophyll to absorb light
- contain enzymes and structures needed for photosynthesis
function of upper epidermis
protect inner cells
adaptation of upper epidermis
- thin layer wo chloroplasts
- let light pass thru for photosynthesis
function of palisade mesophyll layer
tissue in which photosynthesis happens
adaptation of palisade mesophyll layer
- box-shaped cells packed closely tg
- each cell has many chloroplasts to absorb more light
function of xylem
carry water and mineral ions from roots to leaf
adaptations of xylem
- made from dead cells
- form hollow, waterproof tubes thru which water passes
function of phloem
carries sucrose away from leaf
adaptations of phloem
consists of
- sieve tubes (thru which sucrose is transported)
- companion cells (provide energy for transport)
function of vascular bundle
contain xylem and phloem tissues
function of lower epidermis
protect inner cells
adaptations of lower epidermis
- thin layer
- does not contain chloroplasts (except guard cells)
- lets light pass thru for photosynthesis
function of guard cell
- work in pairs
- control size of opening of a stoma
adaptations of guard cell
- entry/loss of water (osmosis) changes shape
- lead to opening/closing of stoma
function of stomata
control diffusion of water vapour and gases in/out of leaf
adaptations of stomata
- size of opening changes
- in response to internal/external environments of plant
function of air spaces
allow diffusion of gases throughout leaf
function of spongy mesophyll layer
site of gas exchange
adaptations of spongy mesophyll layer
- cells loosely spaced
- creates air spaces to allow diffusion of gases throughout leaf
