bio test on who knows really
open vs closed system
open: energy and matter can be exhanged
closed: only allows for exchange of energy.
producers
without them the next trophic level has nothing to eat. they eat sunlight. use chlorophyll to trap light energy. except some producers are chemoautotrophs that thrive near hydrothermal volcanic vents in the ocean floor.
autotrphs
convert co2 into orhanic compounds. light energy from the sun is used to synthesis carbohydrates. the light energy is transferred into bonds between atoms in a carbohydrate molecule.
heterotrophs ingesting other organisms
primary consumers: feed on producers
secondary: feed on primary consumers
other types: herbivores, omnivores, carnivores, scavengers
Trophic levels
T1: producers
T2: Primary consumer
T3: Secondary consumer
T4: Tertiary consumer
T5: Quaternary Consumer
Decomposers
break down the bodies of dead organisms. recycle nutrients so they'er available and not locked inside their bodies or waste.
Detritivores
obtain nutrients by consuming non-living organic sources, such as humus. they digest it internally and absorb what they digest. humus is decaying leaf matter mixed w soil.
Saprotrophs
live on/in non-living organic matter. they secrete digestive enzymes on to the organic matter and absorb the product of digestion. unlike most heterotrophs, they aren't consumers cause they don't ingest it. digestion is external as enzymes are secreted. they are decomposers.
Release of energy in both autotrophs and heterotrophs bu oxidation of carbon compounds in cell respiration
no energy transfer is 100% efficient. wasted thermal energy is produced too. thermal energy is released from the organism dissipates into the ecosystem and is eventually lost from it. they cant convert heat into usable things. that's why ecosystems need a continuous supply of energy (sunlight).
heat lost to environment in both autotrophs due to conversion of chemical energy to heat in cell respiration
ATP produced by an organism through cellular respiration can be converted into electrical energy (nerve impulse), kinetic energy (muscle contractions), and light energy (bioluminescence). these reactions are all exothermic and release heat. living organisms cant convert it into anything.
reasons for energy loss between trophic levels
not fully swallowed, not all food can be absorbed, some die before being eaten, heat loss
from T1 up how much atp is passed on
10% from the previous.
Gross Primary Productivity (GPP)
Total biomass of carbon compounds made via photosynthesis.
Net Primary Productivity (NPP):
GPP minus plant respiration; biomass available to consumers.
secondary production of carbon compounds
Accumulation of carbon compounds in heterotrophs.
Measured in energy or biomass built into consumers per area per unit time.
carbon sinks vs sources
Sink: Absorbs more CO₂ than it releases (e.g., forests).
Source: Releases more CO₂ than absorbed (e.g., fossil fuel combustion).
major carbon fluxes
Photosynthesis, respiration, combustion, ocean-atmosphere exchange, sedimentation.
Carbon cycle
Photosynthesis: CO₂ → organic compounds.
Respiration: Organic compounds → CO₂.
Combustion: Organic matter burns → CO₂.
Methanogenesis: Methane production in anaerobic conditions (e.g., wetlands, digestive
Carbon flows between biosphere, atmosphere, lithosphere, hydrosphere.
Methane can form under anaerobic conditions and be oxidized to CO₂.
finish lesson 3 later pls im tired
pls
Greenhouse gases
gases in the atmosphere that retain heat, largest impact is usually by carbon dioxide and water vapour, others include nitrogen oxides and methane
nitrogen oxides
released naturally by bacteria in some habitats and also by agriculture and vehicle exhausts
methane
released into the atmosphere from marshes, waterlogged habitats and landfills containing dumped organic eastes. It is released during the extraction of fossil fuels and from melting ice in polar regions. Also cows have it
Greenhouse effect
25% of solar radiation is absorbed by the atmosphere, 75% reaches the earth's surface. Earth absorbs short-wave solar energy and re-emits at longer wavelengths. 85% of the re-emitted heat is captured by greenhouse gases and passes back to the earth
enhanced anthropogenic greenhouse effect
there is an increased level of co2, and carbon sinks also take in more of it
positives feedback cycles - terrestrial co2
increased temperatures = more decomposer activity