gcse science biology unit B6 PART 2
- Created by: charlie
- Created on: 27-05-13 10:46
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- B6
- life in water
- adv.
- no dehydration
- less temp. variation
- provides skeletal support (jellyfish)
- waste disposal easily dispersed
- disad.
- more resistant than air
- more energy needed
- control water in body
- diff. waters have diff. solute content
- osmosis
- salt water
- shrivel and die
- fresh water
- swell and burst
- salt water
- osmosis
- diff. waters have diff. solute content
- more resistant than air
- amoebas
- regulate water content
- use contractile vacuoles
- collects water that diffuses in by osmosis
- moves to cell membrane+contracts to empty water
- use contractile vacuoles
- single cell organism
- regulate water content
- plankton live in s+f water
- phytoplankton
- plants
- zooplankton
- animals+feed on phyto.
- pop. varies according to season
- affected by:
- temp
- light intensity
- minerals (nitrates)
- winter +deep water
- light intensity+temp. low
- limit photo. rate
- min. concen. hig
- light intensity+temp. low
- summer+near surface
- light intensity+temp. high
- algae bloom (phyto.)
- zooplank. inc.- more food
- algae bloom (phyto.)
- min. concen. low
- limit photo. rate
- light intensity+temp. high
- affected by:
- phytoplankton
- diff. food webs
- grazing food webs
- begin- living producer - phyto.
- deep water
- bacterial producer- rely on sulphur
- other food webs
- feed on decomposing matter falling
- 'marine snow'
- feed on decomposing matter falling
- deep water
- begin- living producer - phyto.
- grazing food webs
- causes of water pollution
- fertilisers and sewage
- eutrophication
- fertiliser enter water
- nutrients inc. algae
- algae die
- bacteria feed+use up O2
- fish can't respire+die
- bacteria feed+use up O2
- algae die
- nutrients inc. algae
- fertiliser enter water
- indicator species
- sensitive to level of O2
- clean- stonefly nymph
- dirty-sludgeworm
- sensitive to level of O2
- eutrophication
- industrial chemicals and pesticides
- DDT or PCB pollute water
- not broken down in food chain
- passed on+ inc. in concen
- not broken down in food chain
- DDT or PCB pollute water
- fertilisers and sewage
- adv.
- enzymes in action
- biological washing powder
- non-bio- chemicals break up stains
- same chemicals+enzymes for stubborn stains
- products of enzyme reaction are soluble- wash out
- wash out insoluble (stubborn) stains- proteins, starch, fats
- moderate temps- optimum for enzymes
- correct pH
- medical products
- diagnosed by presence of sugar in urine
- first- tasted sweetness
- then- benedicts solution - heated solution changes colour- blue-orange in presence of sugar
- now- reagent strips (enzymes +chemicals)- dipped in urine+change colour in presence of sugar
- immobilised enzymes - measure blood glucose concen daily
- now- reagent strips (enzymes +chemicals)- dipped in urine+change colour in presence of sugar
- then- benedicts solution - heated solution changes colour- blue-orange in presence of sugar
- first- tasted sweetness
- diagnosed by presence of sugar in urine
- food industry
- low-cal. food
- sucrose sweetens home food
- enzyme sucrase breaks down sucrose=glucose+fructose(sweeter)
- use less sugar for same sweet taste
- cheese
- enzyme rennet clots milk in first stages
- juice extraction
- enzyme pectinase breaks down pectin(cell wall in apple+oranges)- causing juice released
- low-cal. food
- immobilised enzymes
- easier to remove
- encapsulate in alginate beads
- mix with enzyme alginate+drop in calcium chloride solution
- encapsulate in alginate beads
- dont contaminate product
- used in continuous process
- make lactose free milk
- immobilise lactase
- breaks down lactose=glucose+galactose
- easily absorbed by lactose intolerant
- breaks down lactose=glucose+galactose
- immobilise lactase
- easier to remove
- biological washing powder
- genetic engineering
- alters genetic code
- able to transfer genes- genetic code universal
- 4 bases
- able to transfer genes- genetic code universal
- genetic modified organism
- transgenic organism
- can be cloned
- transgenic organism
- identify wanted gene
- remove gene from DNA
- cut open DNA of organism that wants it
- insert the gene
- cut open DNA of organism that wants it
- remove gene from DNA
- done using restriction enzymes
- e.g. bacteria engineered to produce insulin
- bacteria loop (plasmid) - vector(carries gene into another organism)
- taken from human cell
- ligase joins DNA strands together
- alters genetic code
- DNA fingerprinting
- forensic science
- paternity tests
- extract DNA from cell sample
- restriction enzymes cut into unique base order
- if DNA section has little section of bases lots of times- cut into smaller bits
- if only few times- cut into bigger bits
- separated- electrophoresis
- fragments suspended in gel+electricity passed through
- DNA negative charge+travels to anode
- smaller bits travel faster +further
- DNA tagged with radioactive probe
- placed on photographic film
- film dark where radioactivity is
- reveals fragments
- look at pattern of DNA fragment positions
- reveals fragments
- film dark where radioactivity is
- placed on photographic film
- DNA tagged with radioactive probe
- smaller bits travel faster +further
- DNA negative charge+travels to anode
- fragments suspended in gel+electricity passed through
- separated- electrophoresis
- if only few times- cut into bigger bits
- if DNA section has little section of bases lots of times- cut into smaller bits
- restriction enzymes cut into unique base order
- life in water
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