4cd- cycles + human inf Flashcards
CARBON CYCLE
- CO2 USED FOR PHOTOSYNTHEISS
- ENERGY PASSES ALONG FOOD CHAIN
- AEROBIC RESP RELEASES INTO AIR
- DECOMP, DEAD CELLS AND CO2 RELEASED INTO SOIL
- FOSSILISATION, STORED AS FOSSIL FUIELS
- COMBUSTION OF FFS RELEASES CO2 BACK INTO AIR
WHY IS NITROGEN CYCLE A THING WHEN IT IS ABUNDANT IN AIR?
- n2 unreactive, unable to take straight from air
- only NH3 & NO3
NITROGEN FIXING BACTERIA
N2 –> NO3 (plant root nodules)
N2 –> NO3 (Lightning gives enough energy to react)
DECOMPOSING BACTERIA
urea/proteins –> into soil –> NH3
NITRIFYING BACTERIA
NH3 –> NO2 –> NO3
DENITRIFYING BACTERIA
NO3 —> N2
NITROGEN CYCLE:
- N2 –> NO3
using a) root hair nodules and nitrogen fixing bacteria OR b) lightning gives enough energy to react)
- N2 –> NH3 –> NO2 –> NO3
using a) decomposing bacteria to convert urea by animal into NH3 and THEN b) nitrifying bacteria to further convert into NO3
- NO3 –> NO2
using denitrifying bacteria to convert back to N2 into atmosphere
greenhouse effect
SUN = SHORT WAVE RADIATION
earth –> reflects as long wave (some)
earth –> absorbs and trapped by GHG in atmosphere
BUTTT excess of GHG trapps too much heat into atmospher = GLOBAL WARMING
GHGS: (5)
- H2O
- CO2
- NO2/NO3
- CH4
- CFCS
CO2 AS A GHG
- burning FFS
- houses, veichles, powerstations, manufacturing
- deforestation (carbon cycle ref.)
NO2/3 AS A GHG
- car fumes (But now catalytic converters)
- fertilisers (denitrying bacteria –> more n2 into earth and reacts w o2)
CH4 AS A GHG
- more cattle from intensive farming and need to feed + product of digestion
- decay of landfills
- rise production, bacteria produce
CFCS AS A GHG
- aerosols and fridges
- destroyed ozone layer
- more uv rays in, cell mutation.. cancer
effects of GLOBAL WARMING
- ice caps melt
- sea level rise
- loss of habitat
- desertification/droughts
- extinctions –> disrupted food chains/migration
- change in ecosystems
- spread of disease
- extreme changes in weather patterns and climate change
CO POISINING
- incomplete combustion of fuel
- binds w haemoglobin
- prevents o2 from being carried in blood
ACID RAIN
- caused by sulfates and nitrates
- fuel inpurities, combusted
- acidic gases dissolve in rain water, producing acidic solutions
effects:
- acidifies lakes
- kills animals and plants
- releases toxic subs from soil
- stops minerals from being absorbed
-destroys limestone
DEFORESTATION
- less evotranspiration: local climate is drier, humidity decreases
- leeching: exposed soil dries up, rainwater runs off and takes minerals w it = infertile soil
- soil erosion: rain causes soil to get washed away, no tree roots hold it in place and less interception
- less o2, more co2
EUTROPHICATION
causes: untreated sewage, pesticides, fertiliser nitrates
process:
LEECHING
excess nitrates in ponds
growth of algae (algal bloom)
blocks light for bottom plants
plants die due to lack of light (no ps)
plants decay and decompose
bacteria uses up o2 in water
anoxic water levels
other animals die
no respiration
