Plant Nutrition I Flashcards
what is the equation for photosynthesis?
carbon dioxide + water –(light / cholorphyll)-> glucose + oxygen
6CO2 + 6H2O —> C6H12O6n+ 6O2
what is chlorophyll?
the chemical found inside chloroplasts which allows plants to absorb light
what are chloroplasts?
they contain chlorophyll
label this chloroplasts and chlorophyll diagram
why are most plants green?
becasue most plants don’t absorb the colour green, they reflect it
during photosythesis … energy is absorbed by a pigment called … which can be found in the … of plant cells
this light energy is then used to convert … from the air to … from the soil into a simple sugar called …
as a by-product of photosnythesis … is made
during photosythesis **light **energy is absorbed by a pigment called chlorophyll which can be found in the chloroplasts of plant cells
this light energy is then used to convert **carbon dioxide **from the air to water from the soil into a simple sugar called glucose
as a by-product of photosnythesis oxygen is made
what is the test for glucose?
glucose made by plants is stored in plants in the form of starch which can be tested by iodine solution which turns from brown to blue/black
how do you test a leaf for starch?
- remove a leaf from a plant
- boil it in a test tube for 30 seconds
- boil it in ethanol to remove colour
- wash the now colourless leaf in cold water
- add iodine solution
how do demonstrate that carbon dioxide is needed for photosynthesis?
soda lime:
soda lime traps carbon dioxide by a chemical reaction and removes it from the air
leaves grown in the presence or absence of soda lime can then be tested for strach production using iodine
in the presence of carbon dioxide, leaves will turn blue/black when tested with iodine
lime water:
alternatively, the consumption of carbon dioxide can be tested using lime water
if photosynthesis has taken place, this will be less cloudy than when photosnythesis has not taken place
how do you demonstrate that light is needed for photosynthesis?
by covering a section of the leaf with paper, no light can get in
light needs to be absorbed by the chlorophll to convert carbon dioxide into glucose for photosynthesis
the section of the leaf covered will remain brown (iodine solution) because no starch is present because glucose has not been made
the non-covered part of the leaf will turn blue/black when tested with iodine solution
how do you demonstrate that chlorophyll is needed for photosynthesis?
test a green area of a leaf (with chlorophyll) with iodine solution and it will turn blue/black indicating that glucose has been made
test a white area of leaf (without chlorophyll) with iodine solution and it will remain brown (iodine colour) indicating that glucose has not been made
how do you demonstrate that oxygen is produced in photosynthesis?
an underwater plant that is good at photosnythesising is placed under water and a test tube on top
the gas formed will collect at thetop of of the test tube
once full, you an test for oxygen by placing a glowing splint in the test tube
if the splint relights oxygen is present
what is the function of a leaf?
to absorb light and carry out photosynthesis (chlorophyll is needed)
to import raw materials for photosynthesis (CO2 and water)
to get rid of photosynthesis waste products (O2)
to export products from photosynthesis to parts of the plant that need them
label this leaf structure
label this leaf cross section diagram
what is the function of the waxy cuticle?
waterproof
reduces water loss
reduced infection by fungi
what is the function of the upper epidermis?
protection
no chloroplasts
absorbs harmful light but allows light for PS to pass through
what is the funtion of the palisade cells?
tightly packed, elongated
lots of chloropasts
high rate of photosynthesis
what is the function of the spongy cells?
loosely packed with air spaces between cells
some chloroplasts
some photosnythesis
what is the function of the air spaces?
between spngy cells
provides air channels through leaf allowing gas exchange
what is the function of the leaf vein: xylem?
rigid vessels with lignin
carry water and minerals from root to stem and leaves
what is the function of the leaf vein: phloem?
vessels of thin living cells
sieve tube cells that form tubes
carry dissolved sugars around the plant to points where suar is used or stored as starch
what is the function of the guard cells?
change shape depending on amount of water inside
control opening and closing of stomata
what is the function of the stomata?
space between guard cells
control the gas exchange and water loss from leaf
how have leaves adapted to absorb light and carry out photosynthesis?
(chlorophyll is needed)
lots of chloroplasts
chlorophyll in palaside cells on top can absorb a lot of sunlight
chloroplasts on all layers absorb all the sunlight that goes through
how doeswater enter the stomata?
by osmosis
when there is light and CO2, does the stomata open or close? how doe sit do this?
opens
guard cells are turgid (filled with water)
when it is dark, there is a drought or it is cold, does the stomata open or close? why?
close
guard cells are flaccid (not filled with water)
how do you carry out a stomata peel observation?
- apply nail vanish to bottom of leaf
- leave for a few minutes
- put cellotape over nail varnished area
- gently peel off cellotaoe
- stick cellotape on glass slide
. observe under microscope