Minerals And Decay Flashcards
Why are nitrates needed
How are they used
Nitrates are needed to make proteins cell growth
They provide nitrogen for amino acids that form the proteins
Why is potassium needed
How is it used
Potassium is used for respiration and photosynthesis
This helps enzymes actions in these processes to speed them up
Why are phosphates needed
How are they used
Phosphates are needed for respiration and growth
It provides phosphorus for DNA for genetic code and cell membranes
Why is magnesium needed
How is it used
Magnesium is needed for photosynthesis
It makes the chlorophyll molecule for photosynthesis
What happens to plants lacking nitrates
Cells don’t grow properly and leaves are yellow
What happens to plants lacking potassium
Have under developed fruit/flowers and discoloured leaves
What happens to plants lacking phosphates
Under developed roots and discoloured leaves
What happens to plants lacking magnesium
Plant unable to make chlorophyll so leaves are yellow
Substances are sometimes absorbed against a concentration gradient
What is this called and what does it require
Substances absorbed from a low to high concentration (opposite direction to diffusion) is called ACTIVE TRANSPORT
It requires energy from respiration
Decay is..
The breakdown of complex substances into smaller ones by microorganisms
How does temperature affect the rate of microorganisms breaking down substances
Microorganisms responsible for decay work at optimum at 40’c
Below this they work slower and above this they denature and cant carry out reactions
How does amount of oxygen affect the rate of microorganisms breaking down substances
Microorganism rate of activity increases as oxygen increases
How does amount of water affect the rate of microorganisms breaking down substances
Microorganisms prefer moist conditions
With too much water,air spaces in the substrate become waterlogged, reducing oxygen supply and reduces decay rate
Why is decay important for plant growth
It releases minerals into the soil for their healthy growth
Other plants can use them
Why does storing food in dry, cool conditions prevent microorganisms and fungi from growing on it
When food is exposed to air, moisture and warmth, microorganisms will quickly grow on it
What are saprophytes
Give examples
Bacteria and fungi are saprophytes
Feed on dead organic material by secreting enzymes onto their food then absorbing the digested products
Saprophytes are essential for decay
What digestion do saprophytes do
Extra-cellular digestion
How does canning preserve food
Food heated to destroy microbes and sealed in sterile container to prevent microorganisms getting oxygen
How does refrigeration/freezing preserve food
Food kept at low temperatures to slow growth and reproduction of microorganisms
How does pickling preserve food
Food pickled in vinegar slows down growth of microorganisms by denaturing their enzymes with low pH
How does adding sugar/salt preserve food
Conditions are too concentrated fir microorganisms to survive
Higher solute concentration draws water out of microorganisms’ cells by osmosis, killing them
How does drying preserve food
Reduces moisture preventing microorganism growth
Detritivores
Give examples
Feed on dead organisms and waste (detritus) produced by living organisms
Earthworms, woodlice and maggots
What is detritus
Waste and dead organisms that feeds detritivores
How do detritivores speed up the process of decay
How do they work with decomposers
Break down detritus into small particles which have a large surface area making it easier for decomposers to feed on
Also the faeces if detritivores also provide food for decomposers
How do humans use decomposer organisms (microorganisms) to break down waste
Feed on human waste in sewage
Break down plant waste in compost
Why are fertilisers used
Minerals are found in soil but in low concentrations so fertilisers ensure the plant gets the minerals it needs (nitrates,phosphates,potassium compounds)
