Abiotic
A term that describes a nonliving factor in an ecosystem.
Active Transport
The movement of particles from an area of low concentration to an area of high concentration that uses energy provided by ATP or a difference in electrical charges across a cell membrane.
Adenosine Triphosphate (ATP)
A molecule that provides energy for cellular reactions and processes. It releases energy when one of its high‐energy bonds is broken to release a phosphate group.
Adhesion
The tendency of water molecules to stick to other surfaces.
Allele Frequency
How often an allele occurs in a population, its relative frequency.
Analogous Structure
A physical structure, present in multiple species, that is similar in function but different in form and inheritance.
Biochemical Conversion
The changing of organic matter into other chemical forms such as fuels.
Bioenergetics
The study of energy flow (energy transformations) into and within living systems.
Biogeochemical Cycles
The movement of abiotic factors between the living and nonliving components within ecosystems; also known as nutrient cycles (i.e., water cycle, carbon cycle, oxygen cycle, and nitrogen cycle).
Biological Macromolecules
A group of biomacromolecules that interact with biological systems and their environments.
Biome
A large area or geographical region with distinct plant and animal groups adapted to that environment.
Biosphere
The zone of life on Earth; sum total of all ecosystems on Earth.
Biotechnology
Any procedure or methodology that uses biological systems or living organisms to develop or modify either products or processes for specific use. This term is commonly associated with genetic engineering, which is one of many applications.
Biotic
A term that describes a living or once‐living organism in an ecosystem.
Carbohydrate
A macromolecule that contains atoms of carbon, hydrogen, and oxygen in a 1:2:1 ratio and serves as a major source of energy for living organisms (e.g., sugars, starches, and cellulose).
Carrier (Transport) Proteins
Proteins embedded in the plasma membrane involved in the movement of ions, small molecules, and macromolecules into and out of cells
Catalyst
A substance that enables a chemical reaction to proceed at a usually faster rate or under different conditions (e.g., lower temperature) than otherwise possible without being changed by the reaction.
Cell
The basic unit of structure and function for all living organisms.
Cell Cycle
The series of events that take place in a cell leading to its division and duplication.
Cellular Respiration
A complex set of chemical reactions involving an energy transformation where potential chemical energy in the bonds of "food" molecules is released and partially captured in the bonds of adenosine triphosphate (ATP) molecules.
Translation
The process in which the messenger RNA (mRNA) molecule on a ribosome is decoded to produce a sequence of amino acids for protein synthesis.
Translocation
The process in which a segment of a chromosome breaks off and attaches to another chromosome.
Trophic Level
The position of an organism in relation to the flow of energy and inorganic nutrients through an ecosystem (e.g., producer, consumer, and decomposer).
Unicellular
Made up of a single cell.
Vestigial Structure
A physical characteristic in organisms that appears to have lost its original function as a species has changed over time.