Zusammenfassung der Ressource
BIOLOGY 4.3
- PLANTS NEED MINERALS
- NITRATES
- Contain nitrogen for making amino acids
- Needed for proteins for cell growth
- Without: poor growth & yellow leaves
- PHOSPHATES
- Contain phosphorus for making
DNA and cell membranes
- Needed for respiration and growth
- Without: poor root growth
& discoloured leaves
- POTASSIUM
- Potassium compounds to
help enzymes in respiration
and photosynthesis
- Without: poor flower/fruit
growth & discoloured leaves
- MAGNESIUM
- Magnesium compounds
for photosynthesis
- Needed to make chlorophyll
- Without: yellow leaves
- ACTIVE TRANSPORT
- Root hairs give the plant a big
surface area for absorbing minerals
- Concentration of minerals in soil
is low - higher in root hair cell
- Uses energy from respiration
to help plant pull minerals into
the root hair against the
concentration gradient (from
low to high conc)
- DECAY
- Things decay because of microorganisms/decomposers
- The rate of decay depends on:
- Temp
- Hotter = faster - respiration
in microorganisms is sped up
- Water
- Moist = fast decay
- Oxygen/air
- More oxygen = faster -
microorganisms can
respire aerobically
- DETRIVORES
- Feed on dead and
decaying material
- e.g. earthworms, maggots, woodlice
- Break material
up into small bits
- This gives a bigger surface area
to work on and speeds up decay
- SAPROPHYTES
- Feed on decaying material
by extracellular digestion
- i.e. feed by secreting digestive enzymes
on to the material outside of their cells
- The enzymes break down the
materials into smaller bits which
can be absorbed by the saprophyte
- Many saprophytes
are fungi
- PRESERVING FOOD
- Canning
- Keeps decomposers out
- Cooling
- Slows
decomposers'
reproduction
rate
- Freezing
- Decomposers can't reproduce
- Drying
- Decomposers need water for cell reactions
- Pickling
- Acid kills decomposers
- Adding
sugar/salt
- High sugar conc = loss of water by
osmosis - decomposers can't work properly