Food Production Flashcards
Use of glasshouses
-provide farmers with an enclosed environment which they can control the climate of and increase crop yields
How are conditions of the glasshouse are manipulated
-additional lighting (winter months)
-burn fuels - higher temp and CO2 and water vapour
-Hydroponics for balance of minerals
-transparent material allows sunlight in for photosynthesis (greenhouse effect)
How does burning fuels increase crop yield
-CO2 (more photosynthesis)
-water vapour (less transportation so plant does not wilt)
-temperature (enzyme activity)
Protein denature
How does the greenhouse effect keep the greenhouse warm
-shortwave radiation enters then reflects off contents of greenhouse
-they reflect off as long wave radiation which cannot pass through glass, so stays in the glasshouse and becomes warmer
What are polythene tunnels/polytunnels
-large plastic tunnels that cover crops
-protect crops from effects of weather
-increase temperature in the tunnel
-prevent entry of pests that can damage plants or diseases
What are fertilisers
-increase the amount of key nutrients in the soil for crop plants
-grow larger and healthy
What are pesticides
-Chemicals kill off unwanted insects and weed species
-less damage done to crop plants by insects
-less competition from other plant species, increasing yield
Organic fertilisers examples
-farmyard manure and compost
Forms of chemical fertilisers
-applied to the soil as dry granules
-sprayed on in liquid form
Use of nitrates and its deficiency in plants
-needed to make amino acids
-weak growth and yellow leaves
Use and deficiency of phosphorus (phosphates) in plants
-needed to make DNA and cell membranes
-poor root growth and discoloured leaves`
Potassium use in plants and its deficiency
-needed for enzymes in respiration and photosynthesis
-poor growth of flower and fruits, brown spots on leaves
Types of pesticides
-insecticides
-herbicides
-fungicides
How do pests, weeds and fungi affect plant crowth
-pests: eat crops and damage them
-weeds: outcompete crop plants for space, water and soil nutrients
-fungi: infect crop plants and spread disease that affects growth and yield
Advantages of pesticides
-accessible and cheap
-immediate effect
-increase crop yield and quality
-can kill entire population of pests
Disadvantages of using pesticides
-organisms can develop resistance
-non specific chemical and can kill beneficial organisms (like bees)
-can lead to bioaccumulation
-need to be repeatedly applied
Biological control
Using a natural predator to eat pest species
Advantages of biological control
-avoids bioaccumulation
-no resistance
-can target specific species
-long lasting
-does not need to be reapplied
disadvantages of biological control
-may eat other organisms instead of the pest
-takes a longer period of time to be effective
-cannot kill the entire population
-may become a pest itself
-may eat other organisms instead of the pest
fermentation
using respiration carried out by microorganisms to make a useful product
how is beer made
-made from barley
-barley is mashed and put into hot water to activate enzymes (starch to maltose)
-yeast added to mixture
-maltose from barley is fermented by yeast
how is bread made
-wheat flour and water are mixed together, then yeast is added
-enzymes from cereal grain in the flour break down starch to form sugars
-yeast respires using sugars
-initially yest respires aerobically
-when air runs out, yeast respires anaerobically and produce more CO2 and ethanol
-CO2 produced is trapped in small air pockets which later rise
-when the dough is baked in the oven, the gas bubbles expand
-baking kills yeast and evaporates the ethanol
anaerobic respiration of lactobacillus in milk
lactose -> lactic acid
what does the lactic acid do in yoghurt
-lactic acid released by the bacteria causes physical and chemical changes in the milk to make yoghurt
-the acid denatures the milk protein, causing it to coagulate
-it also makes the milk taste sour
-the acidity also prevents other microorganisms from growing in the yoghurt, acts as a preservative
how is yoghurt made
-equipment is sterilised to kill other bacteria and prevent chemical contamination
-milk is pasteurised at 85-95C to kill other bacteria
-milk is cooled to 40-45C and lactobacillus bacteria is added
-mixture is incubated at this temp for hours, lactobacillus digest milk proteins and ferment the sugar in milk
-lactobacillus converts lactose into lactic acid and increases acidity sours and thickens the milk in the yoghurt
-yoghurt is stirred and cooled to5C to halt action of the lactobacillus
why is the milk pasteurised and equipment pasteurised in when making yoghurt
-less production, spoil taste
-other bacteria no killed would compete and use lactose in the milk
what are industrial fermenters
-containers used to grow microorganisms like bacteria and fungi in large amounts
-conditions can be carefully controlled to produce large quantities of the microorganisms
useful products that can be made in fermenters
-insulin
-antibiotics
-hormones
-yeast
components of an industrial fermenter
-paddle stirrers
-gas outlet
-water jacket, place to add and remove water
-probes
-equipment to analyse probe
-tap
-air inlet with filter
-nutrient input
-microbe input/tap in
purpose of the paddle stirers
-distribute food nutrients
-distribute oxygen
-distribute heat/even out temp
purpose of gas outlet
-ensures pressure does not build up, CO2 can be collected and sold to fizzy drinks companies
purpose of water jacket
-ensure temp remains constant
-promotes optimum enzyme activity and prevents denaturing of enzymes in microbes
purpose of the probes and the analyser
-these continuously detect the internal conditions within the fermenter, analyser analyses information from probes and adjusts the setting and inputs to maintain optimum conditions
-pH, temp, oxygen levels
purpose of air inlet
supply organisms that respire aerobically with sterile air
nutrient input
provides microbes with energy source and growth materials they require
how are fermenters kept clean
-steam to clean it to kill microorganisms and prevent chemical contamination, ensures only desired microbes will grow
why is fish farming needed
-most fish are caught in the wilds, overfishing has lead to declines in many fish populations
-fish farms raise large numbers of fish in a small space to provide food (protein) for humans
advantages of fish farming over wild caught fish
-fish types: can select species that produce bigger fish and carry out selective breeding
-easy to catch, can catch all year round, produces large numbers
-reduce overfishing, no food chain disruption, sustainable yield
-less risk to fishermen
methods in fish farms to ensure high yields
-control intraspecific predation and overcrowding (separated by size and age)
-control interspecific predation (separated by tanks)
-control disease an infection (kept ion small numbers)
-antibiotics and remove dead fish
-biological control of pests
-control oxygen
-remove waste products (faeces and sewage)
-frequent feeding ion small amounts (no overeating)
-high protein diet
-selective breeding (fish with desired characteristics to reproduce)
-hormones?
-maintain high water quality
