Transcript Topic 2.5 Function

Topic 2.5
Function
Review
• Producers-basis of ecosystems,
constant inputs of energy
• Consumers- do not contain
photosynthetic pigments.
Cannot make their own food
• Decomposers- break down
tissues of dead orgainc matter,
release nutrients back into soil
Photosynthesis
• Convert solar energy into chemical
energy
• Oxygen is a waste product when
water is split
• Imputs-sunlight, CO2, H2O
• Processes- Chlorophyll traps
sunlight, energy used to split H2O,
H from H20 is used to combine with
Carbon to make glucose
• Outputs-Glucose used as (E) source
for plants and for
cont
• Building blocks for other
materials e.g. cellulose, starch
• Output- O2 released from
stomata
• Transformations- Light (E) is
transformed into Chemical (E)
that is stored.
Solar Radiation
Respiration
• Begins as an anerobic process
in the cytoplasm of cells and
moves into the mitochondria
for aerobic reactions
• Controlled by enzymes
Respiration
• Inputs- O2, Glucose
• Processes- Oxidation
Reduction reactions inside cells
• Outputs- Release of (E) for
work and heat
• Transformations- Stored
Chemical energy to kinetic
energy and heat
Carbon Cycle
• Carbon is essential
• Key component of carbohydrates,
lipids, proteins
• Carbon is fixed from simple to more
complex molecules e.g. glucose
• Decomposers release Carbon back
into the atmosphere when they
respire
• Oil/Gas formed when marine
organisms die to bottom of ocean.
• Anaerobic conditions halt decay
process
• Burial/pressure/heat over time
create these fuels
• E.g. Limestone (calcium
carbonate)formed by shells/corals
being crushed and compressed into
sedimentary rock
• Weathering of Limestone, acid rain,
and burning of fossil fuels return
Carbon back into atmosphere
• Denitrifying- N2 is returned;
bacteria removes O2 from
nitrates for use in repiration
• Live in O2 poor soils
Nitrogen Cycle
• Important in amino acids=proteins,
nucleic acids=DNNA
• Most abundant 80%
• Very stable
• Not directly accessible for
plants/animals
• Only certain bacteria (N-fixing) can
generate (E) to convert N2 into
ammonia
• Driven by 4 types of bacteria
–
–
–
–
N fixing bacteria (e.g. mychorrhizae)
Decomposers
Nitrifying bacteria
Dentirifying bacteria
• N-fixing: Azotobacter or Rhizobium
(sybiotic relationship)
• Decomposers- produce ammonia
and ammonium compounds; also
present in excretory compounds
• Nitrifying bacteria- oxidize
ammonia into nitrates and then
nitrites; ammonia/nitrites =toxic to
plants/animals , BUT nitrates are
taken up by H2O=amino
Water Cycle
• One major input= Precipitation
(PPT)
• Two major outputsevapotranspiration (EVT) and run
off
• Storages of water-vegetation,
surface, soil moisture,
groundwater, and water channels.
• Also includes the atmosphere and
the oceans
Gross/Net Productivity
• Primary productivity-The gain
of producers in energy or
biomass
• Secondary-biomass gained by
heterotrophic org. through
feeding
• Can be divided into gross and
net
• GP- Gross Productivity- total gain in
(E) of (BM)/area/time
• GPP- gross primary productivitygained through photosynthesis in
primary producers
• GSP- gross secondary- gained
through absorption in consumers
• NP- Net productivity- the gain in
(E) or (BM) after respiratory losses
( R)
– can have NPP and NSP