5.9 fish farming

• fish have low fat and high protein
• they are efficient at changning nutrients unto fish mass

pros
control over water
control over predators
control over pests
control over diseases

high density of fish -> possiblity of disease

some farmers use antibiotics which are a concern to human health

fish farmers also uses pesticides to keep pests away, which is also a concern to human health

5.8 fermentor

fermentor = vessel where fermentation occurs (made out of copper, steel)

to maintain optimum temperature:
• there is water between the two metal jackets as a 'cooling jacket' since fermentation heats up the fermentor. this cooling jacket will keep the fermentor at an optimum temperature
• steam, which sterilises the fermentor in between fermentations
• there is a heater inside the heater to raise temperature

we also need
• for fermentation to occur, nutrients must be placed inside the fermenter as food for microorganisms
• a probe to measure temperature. informs whether to turn on heater or cooling jacket
• a ph probe to keep ph at the optimum rate
• microorganisms
• turning device to agitate mixture, spreading microorganism
• method of draining product = it will then go into a process called downstream processing which will also purify the product

the idea of the fermentor is the keep the reaction at it's optimum level the whole time, so it will be able to produce the product more efficiently

5.7 yoghurt production

understand the role of bacteria (Lactobacillus) in the production of yoghurt




• the cow produces the milk
• the milk is then pasteurized, which kills any pathogens that might be in the milk
• milk sugars are converted into lactic acids, by incubating the milk at 45-46 degrees in a process called lactobacillus
•lactobacillus produces an enzyme which breaks the milk sugars into lactic acid
• this then solidifies and becomes yoghurt

5.4b biological control

another way to get rid of pesticides:

2. biological control

pros
no toxic chemicals
less impact on wildlife

cons
not 100% effective
hard to control (new species will find alternate prey to feed on and not actually die out)
hard to match predator to prey

5.4a pesticides

large fields of crops all of the same type = monoculture
they tend to be susceptible to pests which feed off the crops which reduces the productivity of farming

1. pesticides (chemicals designed to kill pests)

pros
they are easily obtained
easily applicable
very effective

cons
toxic - might kill plants in the process
bio accumulation - pesticides build up in a food chain causing harm to a food source of a higher trophic level
pests mutate and resist the chemicals - more toxic pesticides have to be used

5.3 fertilisers

•fertilizers increase crop yield by taking the form of nitrates or phosphates (sometimes both)
• they are applied into the soil but are absorbed by the roots into the plant, eventually into the leaf and used in the leaf

• nitrates are used to form proteins inside the leaf
• phosphates are used to help form DNA and membrane structures inside the leaf

fertilizers are divided into two groups:

organic
produced from animal waste which goes through the process of decomposition and fermentation which forms slurry. Slurry provides fields with a supply of nitrates and phosphates to help growth.

artificial
take the form of chemicals, synthetically produced e.g. potassium nitrate solution and ammonium nitrate solution. These are bought and applied to fields and supply the fields nitrates and phosphates.

5.2 crop yield

CO2 + H2O --->(light enzyme) C6H12O6 + O2 = rate of p/s

increasing the concentration of CO2 will result in an increase in the rate of p/s
this will mean an increase in the crop yield

increasing the temperature will result in an increase in the rate of p/s again, but after it peaks you have reached the optimum level (increasing the temperature further would result in a decrease in the rate of p/s

increasing temperature also:
- avoids frost damage
- provides constant temperature