5. Use Of Biological Resources

• sterilise equipment to kill unwanted bacteria • pasteurise milk at 85 degrees for 10-30min • milk is homogenised • milk is cooled to 30-40 degrees to stop good bacteria being killed • inoculated with lactobacillus for 3-12h • if its below the optimum there’s less production and bacteria stops growing • thickened yoghurt is stirred + cooled to 5 degrees

Lactobacillus ferments the lactose to lactic acid so there’s no lactose present

Fruit increases fibre and prevents constipation, natural sweetener stops excess sugar and vitamin C prevents scurvy Fat-free yoghurt has no fat and reduces risk of heart disease

Procès by which humans breed plants or animals with desired characteristics to develop them

• enclosed environment protects crops from harsh weather conditions, pests/diseases • CO2 levels are maintained for photosynthesis • heat trapped from sun creates optimum temp

Paraffin lamps burned increases CO2 levels so it’s not the limiting factor of photosynthesis

Heat trapped by sun increases temperature which is optimum for enzymes in photosynthesis

Contains nutrients so plants grows faster Water soluble => absorbed via active transport

Nitrates - AA for proteins and growth Phosphates - respiration for roots growth Potassium - growth of fruit/flowers/enzymes

Prevents insects eating plants Fungicide/herbicides/insectisices

Quick/efficient Can kill entire pest population

• can develop resistance • nonspecific and can kill other organisms • needs to be applied continuously • bioacculumation -> toxic to others in food chain

Anaerobic respiration => CO2 bubbles

Glucose (C6H12O6) —> ethanol (2C2H5OH) + carbon dioxide (26O2)

• dissolve sugar in boiling tube as glucose • mix yeast and sugar tog in tube • add layer of oil to prevent O2 entering (anaerobic) • connect to lime water test tube • count n. Bubbles For other conditions: water bath or conc sugar

Lactobacullis breaks down lactose sugar to form lactic acid Acid lowers pH of milk and denatures it to protein

Grows bacteria and fungi in large amounts - replicates bacteria and produces large amounts of - useful for transgenic bacteria

Aseptic conditions - no microorganisms grow and contaminate container

Agitation -> stirring paddles are used to ensure everything (nutrients/oxygen/temp/pH/microorganisms) distributed evenly

• contains nutrients needed for microorganisms to use in respiration • optimum temp and pH needed for enzymes so they don’t denature

Cool water keeps temp constant

Provides source of O2 and the filter stops other organisms entering

Creates optimum pH levels for bacteria - usually 6.5

Heat prevents conimatination