Plant nutrition - Unit 3 Flashcards
what is photosynthesis
Photosynthesis describes the process by which plants use light energy to produce glucose.
Palisade mesophyll cells are adapted for photosynthesis by…?
having lots of chloroplast
what is most likely to affect the rate of photosynthesis
change if temperature
Photosynthesis converts..?
Light energy into chemical energy
Why do plants need magnesium
to make chlorophyll
What do phloem vessels transport?
sucrose
If there is no starch in a leaf, this suggests
The leaf has not been able to photosynthesise
how the waxy cuticle on the surface of a leaf aids efficient photosynthesis
It helps to reduce water loss by evaporation
what happens to the rate of photosynthesis if a plant is put in a dark place?
it will stop as there is no light energy available for photosynthesis
2 other factors that can affect the rate of photosynthesis
Temperature
Water availability
why unicellular organisms can rely on diffusion to move substances in and out of a cell
Because substances only have small distances to travel, so the diffusion rate is quick enough.
the word equation for photosynthesis
Carbon dioxide + water → Glucose + Oxygen
the balanced equation for photosynthesis
6 CO2 + 6 H2O → C6H12O6 + 6 O2
where does photosynthesis occur
in chloroplasts
what do plants need glucose for, name 5
respiration stored as starch make amino acids make cellulose for cell walls make lipids
light intensity
Limiting as it provides energy
Increasing light intensity increases
Rate of photosynthesis, while it does this,light is the limiting factor (while the graph increases)
After a point, it no longer increases rate of photosynthesis, another factor has become limiting
(CO2 or temp - when the graph is constant)
carbon dioixide
Limiting as it is a reactant
Increasing CO2 increases rate of
photosynthesis, while it does this, CO2 is the limiting factor (while the graph increases)
After a point, it no longer increases rate of photosynthesis, another factor has become limiting
(light or temp - when the graph is constant)
temperature
Limiting as it affects enzymes
Increasing temp at first increases rate
of photosynthesis, as enzymes / particles have more energy (collide more)
It reaches an optimum for rate of photosynthesis
At too high temps, enzymes denature (active site changes shape) so rate decreases.
where is starch stored
in cells which can photosynthesise
prove chlorophyll is neaded for photosynthesis
No starch as white parts of the leaf do not contain chlorophyll, so do not photosynthesise, so do not produce glucose to store as starch.
name 1 leaf adaptation
large area to absorb more light
name another leaf adaptation
waxy cuticle to prevent water loss
name another leaf adaptation
Upper epidermis transparent
name another leaf adaptation
Palisade cells near surface and tightly packed, to absorb as much light as possible
name another leaf adaptation
Air spaces to allow movement of carbon dioxide
name another leaf adaptation
Vascular bundle where water transported to leaf in the xylem
name another leaf adaptation
Stomata (holes in the bottom of the leaf) which allow CO2 to diffuse into the leaf
name another leaf adaptation
Guard cells to open stomata in day for photosynthesis, and close them at night to prevent water loss.
where does gas exchange occur
in plants occurs through stomata.
why do plants need co 2
for photosynthesis and to produce oxygen
why do plants need oxygen
plants need oxygen for respiration (aerobic) and to produce carbon dioxide
