Biosphere

Abiotic: Non-living components of an ecosystem, such as water, air, temperature, and minerals.

Anoxic: An environment devoid of free oxygen.

Atmosphere: The layer of gases surrounding the Earth.

Autotroph: An organism that can produce its own food from inorganic sources, such as sunlight or chemical energy.

Biomineralization: The process by which living organisms produce minerals, often to harden body structures (e.g., shells, bones).

Biosphere: The sum of all living organisms on Earth and the environments in which they live.

Biota: The living organisms of a particular region or ecosystem.

Calcite Compensation Depth (CCD): The depth in the ocean below which the rate of calcium carbonate dissolution exceeds the rate of its supply, preventing the accumulation of carbonate sediments.

Carbon Cycle: The biogeochemical cycle that describes the movement of carbon through Earth's atmosphere, oceans, biosphere, and geosphere.

Carbon Fixation: The process by which autotrophs convert inorganic carbon dioxide (CO2) into organic compounds, such as sugars.

Chemoautotroph: An organism that obtains energy from the oxidation of inorganic compounds.

Chemotrophy: The process of obtaining energy from chemical reactions.

Cryosphere: The portion of Earth's system that includes all frozen water, such as glaciers, ice caps, and permafrost.

Decomposers: Organisms, primarily bacteria and fungi, that break down dead organic matter, releasing nutrients back into the ecosystem.

Dentrification: The microbial process by which nitrate (NO3-) is converted back to nitrogen gas (N2), releasing it into the atmosphere.

Eukaryote: An organism whose cells contain a membrane-bound nucleus and other organelles.

Extremophile: An organism that thrives in extreme environments, such as those with high temperatures, acidity, or salinity.

Feedback Mechanism: A process in which the output of a system affects its input, leading to either amplification (positive feedback) or dampening (negative feedback) of the original change.

Geobiology: The study of the interactions between Earth's physical, chemical, and biological processes.

Geosphere: The solid, non-living parts of the Earth, including rocks, minerals, and soil.

Gross Primary Production (GPP): The total amount of organic matter produced by primary producers through photosynthesis.

Heterotroph: An organism that obtains its food by consuming other organisms.

Hydrosphere: The portion of Earth that includes all forms of water, such as oceans, lakes, rivers, and groundwater.

Limiting Nutrient: A nutrient that is in short supply relative to the needs of organisms, thereby restricting their growth and reproduction.

LUCA (Last Universal Common Ancestor): The hypothetical most recent common ancestor of all extant life forms on Earth.

Macromolecule: A large molecule, typically composed of many repeating subunits, such as proteins, carbohydrates, and nucleic acids.

Metabolism: The sum of all chemical processes that occur within a living organism to maintain life.

Net Primary Production (NPP): The amount of organic matter produced by primary producers that remains after accounting for their own respiration.

Nitrification: The microbial process by which ammonia (NH3) is converted to nitrite (NO2-) and then nitrate (NO3-).

Nitrogen Cycle: The biogeochemical cycle that describes the movement of nitrogen through Earth's atmosphere, oceans, and biosphere.

Nutrient: A substance that provides nourishment essential for the growth and maintenance of life.

Oxidation: A chemical reaction involving the loss of electrons.

Oxygenic: Pertaining to a process that produces oxygen as a byproduct, such as oxygenic photosynthesis.

Photoautotroph: An organism that obtains energy from sunlight through photosynthesis.

Photoferrotrophy: A form of anoxygenic phototrophy in which ferrous iron (Fe2+) is used as an electron donor.

Phototrophy: The process of obtaining energy from sunlight.

Primary Production: The synthesis of organic matter from inorganic sources by autotrophs.

Prokaryote: A single-celled organism that lacks a membrane-bound nucleus and other membrane-bound organelles.

Reduction: A chemical reaction involving the gain of electrons.

Remineralization: The breakdown of organic matter into inorganic nutrients.

Residence Time: The average length of time a substance remains in a particular reservoir.

Respiration: The process by which organisms break down organic compounds to release energy.

Siderophore: A high-affinity molecule produced by microorganisms that binds to ferric iron (Fe3+), making it soluble and bioavailable.

Sink: A reservoir that absorbs a substance from another part of a system.

Source: A reservoir that releases a substance into another part of a system.

Stromatolite: Layered mounds of sedimentary rock formed by microbial mats, primarily cyanobacteria.

Taxonomic Rank: A hierarchical level in the classification of organisms, such as kingdom, phylum, class, order, family, genus, and species.

Weathering: The breakdown of rocks and minerals at Earth's surface by physical and chemical processes.