Food productionCROP PLANTS

5.1 describe how glasshouses and polythene tunnels can be used to increase the yield of certain crops 5.2 understand the effects on crop yield of increased carbon dioxide and increased temperature in glasshouses

Greenhouses and polythene tunnels raise the temperature, which increases the rate of photosynthesis, which increases crop yield.

(Yield - The total mass of the edible part of crop.) 1) If the level of CO2 in the greenhouse is increased the yield will further increase .

2) Heating units increase temperature and CO2. (combustion)

(remember, CO2 is a limiting factor in photosynethsis)

3) In winter months using artificial lights gives a ‘longer day’ for growing

4) Transparent glass and plastic allow short wave energy in (light) and reflect long wave energy back (heat) to keep temperature high.

Glasshouses and Polythene tunnels5.1 describe how glasshouses and polythene tunnels can be used to increase the yield of certain crops

5.2 understand the effects on crop yield of increased carbon dioxide and increased temperature in glasshouses

What is grown5.1 describe how glasshouses and polythene tunnels can be used to increase the yield of certain crops

High value crops are grown in polythene tunnels and greenhouses.

Some examples are:• Strawberries• Tomatoes• Flowers

Only high value crops make sense to grow in this intensive way. (Value of crop must exceed cost of production)

Fertilizer and Crop Yield5.3 understand the use of fertiliser to increase crop yield

If fertilizers are added (specifically those that contain Potasium, Nitrate and Phosphate– KNP fertilisers) then the yield will increase even more!

Potassium – essential for plant membranes

Nitrate – essential for making plant proteins

Phosphate – essential for DNA and membranes

• Nitrogen is used to make protiens• Proteins increase biomass (more

plant)• Increase in biomass increases

marketable part of the crop (more corn on a plant)

• Increased crop increases revenue(the cost of fertilizer must be less then the increase in value of the

crop)

Fertilizer and Crop Yield5.3 understand the use of fertiliser to increase crop yield

Eutrophication againSimply but Clearly

5.3 understand the use of fertiliser to increase crop yield

Nitrates > Algae Grow > Algae Die >

Algae Decay > No Oxygen >

Fish & Animals Die

Pest Control5.4 understand the reasons for pest control and the advantages and disadvantages of using pesticides and biological control with crop

plants

Pest Control can also be used to increase Yield. This can be done either using pesticides or biological controls.

• Pesticide – a chemical that kills pests (anything that eats your

crop), but does not harm the crop plant • Biological control – introducing a biological organism which will

eat the pest, but not the crop plant (e.g. birds are sometimes encouraged inside greenhouses because they eat caterpillars)

Name some –cides5.4 understand the reasons for pest control and the advantages and disadvantages of using pesticides and biological control with crop plants

• Herbicides• Insecticides• Fungicides• Molluscicides• Fratricides • Suicides• Homicide• Uxoricide• Matricide• Patricide• Vatricide• Deicide• Tomeicide• Mundicide

PlantsInsectsFungiShellfishBrotherSelfPersonWifeMotherFatherPoetsGodBooksEverything

Pesticides5.4 understand the reasons for pest control and the advantages and disadvantages of using pesticides and biological control with crop plants

DDT

Disadvantages of using pesticides:• pesticides may enter and

accumulate in food chains

• pesticides may harm organisms which are not pests

• some pesticides are persistent.

Biological Control5.4 understand the reasons for pest control and the advantages and disadvantages of using pesticides and biological control with crop plants

Advantages and disadvantages of biological control, to include:• advantages:– no need for chemical pesticides– does not need repeated treatment

• disadvantages:– predator may not eat pest– may eat useful species– may increase out of control– may not stay in the area where it is

needed.

Micro Organisms 5.5 understand the role of yeast in the production of beer

Yeast

Remember that yeast are capable of respiring

1) aerobically (producing CO2 and water)

& 2) anaerobically (producing CO2 and ethanol).

Yeast are therefore used in the brewing industry.

MAKING BEER5.5 understand the role of yeast in the production of beer

In order to make beer: • barley seeds are allowed to germinate by soaking

them in warm water (This is called malting). • The germinating barley seeds break down their

carbohydrate stores, releasing sugar. • After a couple of days the barley seeds are gently

roasted (which kills them).• The dead seeds are put into a fermenter with

yeast. • The yeast use the sugar for anaerobic respiration

and produce ethanol.

Well it’s beer

EXPERIMENT 5.6 describe a simple experiment to investigate carbon dioxide production by yeast, in different conditions

You need to know: An experiment that shows the production of CO2 by yeast, in different

conditions:IV (choose one and keep the others constant):a) Type of sugarb) Concentration of sugar (mass meter/measuring cylinder - %)c) Temperature of solution (thermometer – 0C)DV (Measure one):d) Height of frothy bubbles (ruler - cm)e) Volume of CO2 produced (gas syringe - mL)f) Volume of CO2 from delivery tube to inverted container over water

(graduated cylinder – mL)

The best example is to mix a yeast suspension with sucrose Any CO2 produced can be collected over water or bubbled through lime water or

hydrogen carbonate indicator

5.6 describe a simple experiment to investigate carbon dioxide production by yeast, in different conditions

Graphs and Limiting Factors 5.6 describe a simple experiment to investigate carbon dioxide production by yeast, in different conditions

The rate of CO2 production levels off in the experiments over time.

Reason:1) Sugar (glucose/sucrose) is a limiting factor

2) Ethanol is produced which is toxic to micro-organisms (yeast)

MAKING YOGHURT 5.7 understand the role of bacteria (Lactobacillus ) in the production of yoghurt (TA)

Lactobacillus bacterium is This bacterium is used to turn milk into yoghurt.

It uses lactose sugar in the milk to produce lactic acid by anaerobic respiration.

A. The lactic acid affects the milk proteins, making the yoghurt curdle (go solid) and giving it the characteristic tart taste.

B. lowers the pH of milk to inhibit harmful to human bacterial growth

Industrial Fermenters 5.8 interpret and label a diagram of an industrial fermenter and explain the need to provide suitable conditions in the fermenter,

including aseptic precautions, nutrients, optimum temperature and pH, oxygenation and agitation, for the growth of micro-organisms (TA)

Fermenters are huge containers that hold up to 200,000dm3 of liquid.

They make it possible to control the environmental conditions such as: 1. Temperature2. Oxygen3. Carbon Dioxide concentrations4. pH5. Nutrient levels

This allows microorganisms can grow and respire without being limited and can work as efficiently as possible

(High Yield)

It is very important the everything in the fermenter is sterile, so that only the

microorganisms that are wanted grow in the culture.

Fermenters are used to produce commercially:• Penicillin (antibiotic) in aerobic conditions• Beer (ethanol) in anaerobic conditions• Yoghurt (lactic acid) in anaerobic conditions

MAKING MONEY FROM BACTERIA5.8 interpret and label a diagram of an industrial fermenter and explain the need to provide suitable conditions in the fermenter, including

aseptic precautions, nutrients, optimum temperature and pH, oxygenation and agitation, for the growth of micro-organisms (TA)

FERMENTER5.8 interpret and label a diagram of an industrial fermenter and explain the need to provide suitable conditions in the fermenter, including

aseptic precautions, nutrients, optimum temperature and pH, oxygenation and agitation, for the growth of micro-organisms (TA)

Important details: Water Cooling jacket – keeps the microorganisms at optimum temperature. They will produce lots of heat through respiration, therefore need to be cooled! Paddles – keep stirring the mixture. This stops waste products from building up and keeps the air evenly mixed Nutrient medium – supplies the microorganisms with fuel for respiration Sterile Air supply – supplies clean O2 for respiration (note: this is not required in anaerobic fermentation processes) Data-logger – monitors temperature and pH, keeps the fermenter at optimum conditions

Fermenter Diagram5.8 interpret and label a diagram of an industrial fermenter and explain the need to provide suitable conditions in the fermenter, including aseptic precautions,

nutrients, optimum temperature and pH, oxygenation and agitation, for the growth of micro-organisms (TA)

You don’t need to be able to draw this out, but you could be asked to label a diagram of a fermenter or be asked to explain the function of the various parts of a fermenter.

STOPPING THE O2, RELEASING CO25.8 interpret and label a diagram of an industrial fermenter and explain the need to provide suitable conditions in the fermenter, including aseptic

precautions, nutrients, optimum temperature and pH, oxygenation and agitation, for the growth of micro-organisms (TA)

The valve • releases CO2 under pressure• stops Oxygen and

microorganisms from entering

Why Fish farming(overview) 5.9 explain the methods which are used to farm large numbers of fish to provide a source of protein, including maintenance of water quality,

control of intraspecific and interspecific predation, control of disease, removal of waste products, quality and frequency of feeding and the use of selective breeding.

• Control feeding diet quality and frequency• Control water quality, temperature and waste removal• Control predation• Control disease and parasites

• Select for species, size and quality• No boats needed and a guaranteed harvest

• Less overfishing of natural wild fish stocks• No risk of catching unwanted (non-marketable species)

Fish farming5.9 explain the methods which are used to farm large numbers of fish to provide a source of protein, including maintenance of water quality, control of intraspecific and interspecific predation, control of disease, removal of waste products, quality and frequency of feeding and the use of selective

breeding.

Fish are farmed in fish farms because they are a good source of protein.

1) Fish farms keep lots of fish in very small tanks to minimize space requirements.

2) To stop the fish fighting with each other these precautions are taken;

Fish farming5.9 explain the methods which are used to farm large numbers of fish to provide a source of protein, including maintenance of water quality, control of intraspecific and interspecific predation, control of disease, removal of waste products, quality and frequency of feeding and the use of selective

breeding.

To reduce predation:

• Nets cover tanks• Barriers separate tanks

Basic Points5.9 explain the methods which are used to farm large numbers of fish to provide a source of protein, including

maintenance of water quality, control of intraspecific and interspecific predation, control of disease, removal of waste products, quality and frequency of feeding and the use of selective breeding.

- Different fish species are kept in separate tanks. This stops competition between species of fish (interspecific competition) - Fish of different genders are kept separately (unless they are being bred) - Fish of different ages are kept separately. This stops competition between fish of the same species (intraspecific competition)

INCREASING YIELD5.9 explain the methods which are used to farm large numbers of fish to provide a source of protein, including maintenance of water quality,

control of intraspecific and interspecific predation, control of disease, removal of waste products, quality and frequency of feeding and the use of selective breeding.

The fish are fed often and in small amounts, or fed with protein-rich food

(where does the protein come from?)

Sometimes hormones are added to the water to speed growth.

Only the biggest and most healthy fish are allowed to breed.

(The small and unhealthy fish end up as fish food.)

This is an example of selective breeding.

INCREASING YIELD, DECREASING DISEASE, MAKING SUPERBUGS AND AFFECTING CONSUMERS

5.9 explain the methods which are used to farm large numbers of fish to provide a source of protein, including maintenance of water quality, control of intraspecific and interspecific predation, control of disease, removal of waste products, quality and frequency of feeding and the use of selective breeding.

The use of antibiotics will increase the rate of growth (yield) & decrease incidence of disease.

Pesticides decrease the growth and spread of parasitesNegatives:1. It can also selectively breed antibiotic resistant bacteria. 2. Pesticides can kill other invertebrates3. Pollution from organic material leads to eutrophication4. Antibiotics may not degrade and can be passed on to

consumers (humans).

DECREASING DISEASE5.9 explain the methods which are used to farm large numbers of fish to provide a source of protein, including maintenance of water quality,

control of intraspecific and interspecific predation, control of disease, removal of waste products, quality and frequency of feeding and the use of selective breeding.

Water is closely monitored.

Fish are continuously supplied with fresh sterile water so that wastes and excess nutrients are washed out constantly.

The fish are kept in sterile water to limit disease, which would spread very quickly in the cramped ponds.

DECREASING DISEASE5.9 explain the methods which are used to farm large numbers of fish to provide a source of protein, including maintenance of water quality,

control of intraspecific and interspecific predation, control of disease, removal of waste products, quality and frequency of feeding and the use of selective breeding.

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