Transfers of energy

• An ecosystem, in terms of energy and matter, an open system
• Sunlight is the principal source of energy for most ecosystems
• In a food chain, decomposers break down dead organisms
• Autotrophs are organisms that synthesize their own food from simple substances
• Photoautotrophs uses light as an external energy source
• Heterotrophs obtain their carbon compounds from other organisms
• In cell respiration, energy is released by the oxidation of carbon compounds
• Energy pyramids illustrate the loss of energy at each trophic level
• Cell respiration contributes to heat loss in both autotrophs and heterotrophs
• The number of trophic levels in ecosystems is limited due to energy losses between levels
• Primary production refers to the accumulation of carbon compounds in the biomass of autotrophs
• Secondary production refers to the accumulation of carbon compounds in the biomass of heterotrophs
• Ecosystems can act as carbon sinks by absorbing carbon dioxide
• The Keeling Curve shows the concentration of carbon dioxide
• Photosynthesis produces oxygen required for aerobic respiration
• In ecosystems, biomass refers to the total mass of living matter at each trophic level, which decreases significantly from producers to apex predators
• The Nitrogen cycle is critical for regulating the availability of a key element in ecosystems, which is essential for the synthesis of proteins and nucleic acids
• A ecological pyramid is a graphical representation that shows the relative amounts of energy or matter contained within each trophic level in a given food chain or food web
• In the biomagnification effect, the accumulation of toxins in the tissues of organisms increases as it moves up the trophic levels of a food chain
• The carbon cycle involves the exchange of this element between the atmosphere, hydrosphere, lithosphere, and biosphere, influencing global climate.
• The process by which bacteria and fungi break down dead organic material into simpler substances is known as decomposition
• During carbon synthesis, autotrophs convert inorganic carbon dioxide into organic molecules, which are then available for other organisms in the ecosystem.
• The efficiency of energy transfer between trophic levels, typically around 10 percent, limits the length of food chains in ecosystems.
• The Bottom-Up Control hypothesis suggests that nutrient supply, productivity, and the type of primary producers control the structure of an ecosystem from the bottom up.
• Carbon cycle diagrams are made with boxes for pools (carbon stores/reserves) and arrows for directions of flux (transfer of elements from one pool to another)
• Places can either be sinks or sources. Sources boast lower photosynthesis rates than cellular respiration rates and hence emits carbon. Sinks boast more photosynthesis than cellular respiration and store carbon.
• For atmospheric carbon to be stable, the uptake of carbon from the atmosphere (sinks) needs to be equal to the release of carbon from the atmosphere (sources).
• While photosynthesis and cellular respiration are the largest fluxes of carbon, it is affected by carbon and fossil decomposition rates, biosequestration (storing carbon to build shells), fires, and combustion.
• CHONP needs to be recycled by decomposers to avoid facing limited supply. (Solar) energy flows, nutrients cycle.
• Keeling curve showing carbon in atmosphere shows general upward trend due to human activities. Yearly fluctuations can be explained with seasons and their effect on photosynthesis
• Heat loss, transpiration, incomplete combustion (not consuming all parts of our foods) and incomplete digestion (some excreted without absorption due to lack of enzymes to process them cause 90% energy + biomass loss at every new trophic level
• Heat cannot be converted back to usable chemical energy so it cannot be passed through trophic levels but can help organism with things like regulating body temperature
• GPP (gross primary production) is the total biomass of carbon made during photosynthesis
• NPP (net primary production) is the total biomass of carbon made during photosynthesis that is actually passed onto the next trophic level/not used by photosynthesizing plant
• Producers take inorganic chemical compounds into organic compounds
• Open caves find nutrition in DOM, feces, and dead animals that come into cave
• Closed caves find nutrition in chemosynthetic bacteria that forms with the energy released from chemical reactions.
• Ecosystems are open systems usually but can thrive in closed systems by using sunlight for photosynthesis, recycling nutrients, and hence creating its own ecosystem with its own density dependent factors (ex. too many plant, too many nutrients needed, not enough=deaths)
• Energy systems can exchange both energy AND matter
• Organism in caves often are blind as eyes are unused in the dark and hence an inefficient use of energy