Use of Biological Resources Flashcards
how can we use microorganisms
Microorganisms can be used by humans to produce foods and other useful substances
why do we need flour in bread
contains starch which the yeast can break down into glucose for respiration
why do we need water in bread
to bind the ingredients
to active the dry yeast
why do we need yeast in bread
respires the glucose which creates air pockets in the bread making it rise
why do we knead bread
to mix all the ingredients together and to increase the SA
why do we prove the bread
prove at 35-40c which is optimum temperature for yeast which allows them to respire quickly
allows the yeast to respire and rise and create the air bubbles (CO2) in the bread
why do we bake the bread
the high temperature denatures the enzymes in the bread stopping them from respiring further
high temperature also evaporates the ethanol produced from anaerobic respiration
5.6 practical - investigate the role of anaerobic respiration by yeast in different conditions
- Dissolve sugar in previously boiled water.
- Add yeast and mix to form a suspension, and pour into a boiling tube.
- Add a layer of vegetable oil. (prevents any oxygen getting to the yeast making the yeast respire anaerobically)
- Connect a delivery tube to a second boiling tube, this time containing limewater
to investigate temperature place the boiling tube with the yeast into a warm water bath (not too hot other the enzymes would denature)
to investigate sugar concentration change the amount of sugar added to the yeast
the limewater will turn cloudy as the yeast respires as it will produce CO2
anaerobic respiration formula in bacteria and fungi
glucose –> ethanol + carbon dioxide
what is the type of bacteria used to create yogurt
lactobacillus bulgaricus
how does lactobacillus produce yogurt
Lactobacillus respires anaerobically producing lactic acid. This lowers the pH, acting as a preservative. The acid also coagulates the milk protein, as the acidic conditions change the shape of the proteins, giving yoghurt its texture and flavour
how is milk converted to yogurt
treated at 90c to remove oxygen, kill any harmful bacteria present, change proteins
cooled to 46c which is the optimum temperature for the bacteria
bacteria then respires and creates lactic acid which creates the acidic taste in yogurt
how can glasshouses and polythene tunnels be used to increase the yield of certain crops
growing plants outside does not allow the farmer to control any factors affecting photosynthesis
by growing plants in an enclosed environment the farmer can control these factors better
how do glasshouses and polythene tunnels increase crop yield
several conditions can be manipulated and controlled
artificial heating - enzymes controlling photosynthesis can work faster due to more kinetic energy
artificial lighting - plants can photosynthesis for longer
increasing cardon dioxide content - plants can photosynthesis quicker
regular watering - plants can photosynthesis quicker
high moisture content - lots of water water vapour reduces water loss via transpiration allowing the plants to keep stomata open
burning fossil fuels or wood raises the temperature and also produces CO2 and water vapour
they also protect crops from effects of the weather:
- excessive wind
- excessive rain
- extreme temperatures
what effect does increased CO2 levels have on crop yield
plants can photosynthesis quicker and so grow quicker
the more CO2 present the more photosynthesis however at some point other factors will become limiting
what effect does increased temperature have on crop yield
enzymes controlling photosynthesis can work faster due to more kinetic energy so more photosynthesis and growth
if temperature increases too much then the enzymes will denature
how can fertiliser increase crop yield
fertilisers increase the amounts of key nutrients in the soil for crop plants meaning the plants can grow larger and quicker and are more healthy which increase yields
what mineral ions does fertiliser provide
Nitrogen:
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
Phosphorous:
Absorbed in the form of phosphates
Needed to make DNA and cell membranes
Lack of phosphorus can cause poor root growth and discoloured leaves
Potassium:
Absorbed in the form of various compounds of potassium
needed in vital processes such as photosynthesis and water + nutrient transport
Lack of potassium can cause poor growth of flowers and fruits, as well as brown spots on leaves
advantages of organic fertilisers
improves soil structure
greater range of minerals
releases minerals over a longer time period
less cost
disadvantages of organic fertilisers
slow acting
may contain pests
harder to apply then inorganic ones
advantages of inorganic fertilisers
releases minerals quickly
contents known
easy to apply
disadvantages of inorganic fertilisers
can lead to eutrophication
requires regular reapplication
why do we need pest control
Pests such as insects and other animals can damage crops by eating them
Weeds can outcompete crop plants for space, water and soil nutrients
Fungi can infect crop plants and spread disease which can affect growth and yield
advantages of pesticides
easily accessible and relatively cheap
immediate effect
kill entire population of pests
disadvantages of pesticides
the organisms can develope a resistance to the pesticide
non-specific chemicals which kill other organisms
the chemicals don’t break down so can lead to bioaccumulation
need to be repeatedly applied
advantages of biological control
natural method so no pollution
no resistance can be built up
can target specific species
long lasting
does not need to be repeatedly applied
disadvantages of biological control
may eat other organisms instead of the pest
takes a longer time to be effective
cannot kill entire population so some pests will always be present
may not adapt to the new enviroment or may move out of the area
may become a pest itself
how can selective breeding develop plants with desired characteristics
pick 2 best plants with desired characteristics and breed them
pick 2 best offspring and breed again
this reduces the gene pool and increases the chances of getting desired genes
how can selective breeding develop animals with desired characteristics
pick 2 best animals with desired characteristics and breed them
pick 2 best offspring and breed again
this reduces the gene pool and increases the chances of getting desired genes
what are some examples of desired characteristics animals are bred for
disease resistance
quicker growing
quicker reproduction
fur coat colour
advantages of fish farming
raises a lare number of fish in a small area
allows for selective breeding
protection against predators
can control water quality
control feeding
fish farming water quality method
water is filtered to remove waste and harmful bacteria which prevents diseases
water is also cleaned to maintain high levels of O2 for aerobic respiration
fish farming control of intraspecific predation method
fish are seperated based on size and age so to minimize the chance of them eating each other
fish farming control of interspecific predation method
different species are seperated by nets and tanks to prevent fighting
fish farming control of disease method
antibiotics are given to fish as well as fish being kept in small numbers to stop disease spread
fish farming removal of waste products method
water is filtered to remove faeces and sewage and the tanks are cleaned
fish farming feeding method
fish are fed food that is high in nutrients to ensure fast growth
fed little and often to not waste food and prevent them over eating or eating each other
fish farming use of selective breeding method
fish are seperated by gender so that farmers can selectively breed
suitable conditions needed in an industrial fermenter
aseptic precuations - must clean fermenter with steam to kill other microorganisms and prevent chemical contamination to ensure only desired organisms grow
nutrients - nutrients are needed in respiration to ensure the bacteria can reproduce
optimum temp + pH - must be kept at optimum temp + pH for the enzymes of the desired microorganisms to allow them to reproduce as quick as possible
oxygenation - oxygen is needed for aerobic respiration
agitation - stirring paddles ensures that microorganisms, nutrients, oxygen, temperature and pH are evenly distributed
what is the use of an industrial fermenter
Fermenters are containers used to grow (‘culture’) microorganisms like bacteria and fungi in large amounts
These can then be used for brewing beer, making yoghurt and mycoprotein and other processes not involving food, like producing genetically modified bacteria and moulds that produce antibiotics (e.g. penicillin)
The advantage of using a fermenter is that conditions can be carefully controlled to produce large quantities of exactly the right type of microorganism
what does transgenic mean
the transfer of genetic material from one species to a different species
genetic engineering process
insulin hormone gene cut from a human chromosome using restriction enzymes
plasmid opened up using restriction enzymes (same restriction enzymes must be used from cutting out the insulin so the sticky ends (short sections of single stranded DNA which want to join to their corresponding base) are matching allowing the plasmid to join together)
insulin hormone gene inserted into plasmid by ligase enzyme which joins the sticky ends together if they are corresponding
plasmid with insulin gene inserted into a bacteria cell which becomes transgenic organism
copies of insulin gene created when bacteria reproduce inside fermenter
molecules of insulin hormone purified and packaged
what is a vector
plasmids or viruses as they can take up pieces of DNA and insert the recombinant (DNA of two different organisms) DNA into other cells
viruses - transfer DNA into human cells or bacteria
plasmids - transfer DNA into bacteria or yeast
conditions inside a fermenter for genetic engineering
lots of food for respiration
oxygen for aerobic respiration
stirrer to increase SA to mix food and bacteria and oxygen
cooling jacket to keep cool as temp will increase due to respiration and this prevents enzymes (DNA and RNA polymerase) denaturing
ways to genetically modify a plant to improve food production
crop plants can be GM to contain a gene which produces a poison which kills insects making the plant resistant to insect pests which improves crop yield
crop plants can be GM to make them resistant to some herbicides so when herbicide is sprayed on field it only kills weeds allowing crop plants to get more nutrients
crops can be GM to improve additional vitamins and improved nutritional value which helps improve deficiency diseases in the world
crops can be GM to be drought resistant which improves crop yields
advantages of GM crop plants
more precise than selective breeding
higher crop yield
less pesticides/herbicides used so less pollution
disease/pest/herbicide resistant
disadvantages of GM crop plants
ethical issues
unknown long term affects
may affect food chains and the environment
reduces variation
process of cloning an animal
take a nucleus (diploid as from adult body cell) from the animal you want to clone
insert taken nucleus into enucleated (empty) egg cell using a micropipette
electric shock the now full egg cell
shock causes mitosis to begin in the egg
once egg has replicated enough to form an embryo, insert into uterus of carrier animal (surrogate mother)
how can cloned transgenic animals be used to produce human proteins
transgenic organism contains an foreign gene in its DNA (human protein gene)
the animal is then bred and the gene causes the animal to produce the human protein in its milk
what is micro propagation
how plants are cloned also called tissue culture
method of micropropagation
cut off a growing tip from a healthy parent plant
dip tip into a sterilising fluid to kill any bacteria or fungi present
cut tip into many pieces
each piece is placed in a test tube containing sterilised agar (contains nutrients needed for plant to grow) jelly which is sloped diagonally to prevent any condensation produced to not drown the plant
once plant has grown enough plant in soil
how can micropropagation be used to produce commercial quantities of genetically identical plants
It allows a variety of a plant with desirable characteristics to be produced:
Cheaply
With a greater yield (a large number of plants can be produced per square metre)
Quickly (the plantlets are ready to grow into mature plants)
At any time of the year
Identical to each other (so they retain the desired characteristic)
Disease-free or resistant plants can be bred
