plant Flashcards
function of waxy cuticle
Protective layer,
prevents excessive
water loss from leaves
so that they do not dry
out
Upper epidermis
Thin and Transparent
to allow as much light
as possible to reach
the photosynthesizing
cells
Palisade mesophyll cells
Where most
photosynthesis takes
place; found in the
uppermost half of leaf to
receive as much
sunlight.rectangular to pack tightly,contains large central vacuole
Stomata function
Largely found on
underside of leaf, allows
for movement of air in
an out of leaf for
efficient gas exchange,
allows for water loss
vascular bundle function made of xylem and phloem
Xylem: transports
water and minerals
from roots to leaves
Phloem: transports
sucrose from leaves
to other parts of the
plant
Adaptation of leaf being thin
Allows carbon dioxide to diffuse to palisade mesophyll cell quickly
Adaptation of large surface area
Increase surface area for the diffusion of carbon dioxide and absoroption of light for photosynthesis
Adaptation of chlorophyll
Absorbs light energy so photosynthesis can take place
Network of veins
Allows transport of water to the cells of the leaf and carbohydrates from the leaf for photosynthesis
epidermis is thin and transparent
alows more light to reach the palisade cells
thin cuticle made of wax
protect leaf without blocking sunlight
palisade cell layer at top of leaf
maximises the absorption of light as it will hit chloroplast directly
spongy layer
air spaces allow carbon dioxide to diffuse through leaf,increasing surface area
vascular bundles
thick cell wall of tissue in bundle help support stem and leaf
chloroplast
contain chlorophyll to absorb light energy,pcked at sides of cell
Photosynthesis definition
process where green plants where in the presence of light energy and chlorophyll produce oxygen and glucose from carbon dioxide and water.oxygen is waste product
process of photosynthesis
carbon dioxide enters through stomata in leaves,water enter through roots,sunlight absorbed by chlorophyll and chemical reaction happens and glucose made and oxygen exits through stomat
products of photosynthesis
final product is glucose,but leaf stores excess glucose as starch because starch molecules are long chains of glucose,they are insoluble and can be stored in cells without affecting water potential and osmosis,some plants store large amounts of starch in tubers
How is glucose transported?
it is transported in the form of sucrose(fructose+glucose),soluble but not as reactive as glucose,so its more easily carried arount the plant
How is photosynthesis tested
remove leaf and place in boiling water,place leaf in hot ethanol by putting over water bath which dissolves chlorophyll,waash leaf in cold water and add iodine to leaf on petri dish
Investigating factors needed for photosynthesis
Light-put one in light and one dark,carbondioxide-2 bell jars-one with carbon dioxide and one with carbon dioxide removed by potassium hydroxide,chlorophyll-using variegated leaves,white portion doesnt have chlorophyll
other methods to test photosynthesis
volume of oxygen produced,oxygen sensor probe connected to data logger,time taken for submerged leaf discs to rise,measures oxygen production
factors affecting photosynthesis
temperature,light intensity,carbon dioxide concentration
Why does temperature affect photosynthesis
Enzymes are required for photosynthesis and they have an optimum temperature(above optimum temperature rate falls off)
