Plant and Animal Physiology Flashcards
ecosystem
Earth is a closed system with respect to matter, but open with respect to
energy – driven by the sun
what elements move around the earth in cycles through living organisms and nonliving
oxygen, carbon, nitrogen, phosphorous and sulfur
flux
the rate at which elements are moved through the cycle
pool
where elements accumulate
sinks
where elements are taken out of the cycle for a long time
photosynthesis
Evolved 2.5 bil yrs ago
• Converts sunlight energy to biological energy
cyanobacteria
earliest photosynthetic organisms, changed the atmosphere
so aerobic organisms could exist
atmosphere is made up of
mostly N (78%), some O (21%) and very little CO2 (0.03%)
CO2
most oxidized form of Carbon, also most stable
Organisms became able to reduce CO2
o Energetic uphill battle so used energy from the sun
• Made Carbon form CO2 useful for other organisms
photosynthesizers
Primary producers
o Solar energy enters the ecosystem through these organisms
o Use some of the energy they assimilate for their own metabolism – the
rest is available to consumers (net primary production)
Net primary production
a rough measure of energy flow through ecosystems
can be a measure of energy flowing in
Ocean and tropics are the most important – over 2/3 of the
world’s net primary production!
Carbon Cycle
All organisms contain carbon and their
energy comes from carbon compounds.
Carbon is removed from the atmosphere
as CO2 and incorporated into reduced
organic (carbon-containing) molecules
by photosynthesis.
Carbon is returned to the atmosphere as
CO2 by organisms in their metabolism
of reduced organic molecules.
where does carbon pool
in oceans
where does carbon sink
in fossil fuels and rocks
total production vs total consumption
CO2 production exceeds its consumption, but studies on global
warming must be analyzed skeptically
auxotrophs
producers
plants, algae, bacteria
photosynthetic organisms
Waste products of producers are fuels for consumers
formula of photosynthesis
CO2 + H2O +energy –> CH2O + O2
reduced form of oxygen (H2O) to oxidized form of oxygen
CO2 is oxidized, goes to reduced form (CH2O)
H2O is vary stable so it contributes to the energetic uphill battle
Heterotrophs
consumers (animals, fungi, bacteria)
Respiration (aerobic metabolism): O2 + CH2O –>energy + H2O
+CO2
heterotroph waste products are autotroph fuels
aerobic metabolism
•Energy is derived from carbohydrates. Oxygen from the
atmosphere is combined with carbohydrates to liberate the stored
energy. Water and carbon dioxide are waste products.
angiosperms
dominant plant life
3 types of vegetative organs: roots, stems, and leaves organized into shoot systems and root systems
shoot system
stems, leaves, flowers
Leaves: main organs for photosynthesis; absorb light and make sugar
stem: holds things together, holds leaves to face the sun; connections btw roots and leaves
root system
anchors plant, absorbs water and mineral nutrients; stores products of photosynthesis
water pathway in plants
water comes in through roots, moves up to leaves.
sunlight pathway
comes into leaves
