food production Flashcards
what conditions can be manipulated in a glasshouse
Artificial heating (enzymes controlling photosynthesis can work faster at slightly higher temperatures - only used in temperate countries such as the UK)
Artificial lighting (plants can photosynthesise for longer)
Increasing carbon dioxide content of the air inside (plants can photosynthesise quicker)
Regular watering
what farmers in tropical countries may consider to manipulate?
need to be ventilated to release hot air and avoid temperatures rising too high, which could cause the denaturation of the enzymes controlling the photosynthesis reaction
polyethene tubes
large plastic tunnels that cover crops
polythunels uses
They can protect crops grown outside from the effects of the weather, including excessive wind, rain and extreme temperatures
They also increase the temperature slightly inside the tunnel
They can prevent the entry of pests that can damage plants or diseases that can kill plants
3 limiting factors of photosynthesis
Temperature
Light intensity
Carbon dioxide concentration
how does temperature affect the rate of photosynthesis
.temperature increases the rate of photosynthesis
.this is only to a certain point as enzymes begin denature and the rate of reaction decreases.
how does light affect the rate of photosynthesis
more light, faster rate of photosynthesis
This trend will continue until some other factor required for photosynthesis prevents the rate from increasing further because it is now in short supply
how does carbon dioxide affect the rate of photosynthesis
.more carbon dioxide faster rate of photosynthesis
.This trend will continue until some other factor required for photosynthesis prevents the rate from increasing further because it is now in short supply
fertilisers
increase the amount of key nutrients in the soil for crop plants, therefore plants can grow more larger and healthy which increases crop yield
pesticides
these chemicals kill off unwanted insects and weed species, meaning that there is less damage done to crop plants by insects, as well as reducing competition from other plant species, which increases yields
organic fertilisers
manure and compost
chemical fertilisers
dry granules or can be sprayed on in liquid form
They mainly provide crop plants with nitrogen, phosphorus and potassium:
nitrogen in fertilisers
Absorbed in the form of nitrates
Needed to make amino acids which are the building blocks of proteins
Lack of nitrogen causes weak growth and yellowing of the leaves of plants
potassium in chemical fertilisers
Absorbed in the form of various compounds of potassium
Allows enzyme reactions to take place to produce ATP in respiration as well as being needed for the enzymes involved in photosynthesis
Lack of potassium can cause poor growth of flowers and fruits, as well as brown spots on leaves
phosphorus in fertilisers
Absorbed in the form of phosphates
Needed to make DNA and cell membranes
Lack of phosphorus can cause poor root growth and discoloured leaves