algae: Single-celled organisms, once considered plants (they aren’t). As aquatic organisms, they grow in water. Like green plants, they depend on sunlight to make their food.
astronaut: Someone trained to travel into space for research and exploration.
carbon: A chemical element that is the physical basis of all life on Earth. Carbon exists freely as graphite and diamond. It is an important part of coal, limestone and petroleum, and is capable of self-bonding, chemically, to form an enormous number of chemically, biologically and commercially important molecules.
carbon dioxide: (or CO2) A colorless, odorless gas produced by all animals when the oxygen they inhale reacts with the carbon-rich foods that they’ve eaten. Carbon dioxide also is released when organic matter burns (including fossil fuels like oil or gas). Carbon dioxide acts as a greenhouse gas, trapping heat in Earth’s atmosphere. Plants convert carbon dioxide into oxygen during photosynthesis, the process they use to make their own food.
chemistry: The field of science that deals with the composition, structure and properties of substances and how they interact. Scientists use this knowledge to study unfamiliar substances, to reproduce large quantities of useful substances or to design and create new and useful substances. (about compounds) Chemistry also is used as a term to refer to the recipe of a compound, the way it’s produced or some of its properties. People who work in this field are known as chemists.
crop: (in agriculture) A type of plant grown intentionally grown and nurtured by farmers, such as corn, coffee or tomatoes. Or the term could apply to the part of the plant harvested and sold by farmers.
cyanobacteria: A type of bacteria that can convert carbon dioxide into other molecules, including oxygen.
electricity: A flow of charge, usually from the movement of negatively charged particles, called electrons.
microbe: Short for microorganism. A living thing that is too small to see with the unaided eye, including bacteria, some fungi and many other organisms such as amoebas. Most consist of a single cell.
organism: Any living thing, from elephants and plants to bacteria and other types of single-celled life.
oxygen: A gas that makes up about 21 percent of Earth’s atmosphere. All animals and many microorganisms need oxygen to fuel their growth (and metabolism).
particle: A minute amount of something.
photosynthesis: (verb: photosynthesize) The process by which green plants and some other organisms use sunlight to produce foods from carbon dioxide and water.
protist: A broad group of mostly single-celled organisms that are neither plants nor animals. Some, like algae, may appear plant-like. Those known as protozoans may appear animal-like. And still others appear fungi-like. More blob-like members of the group are known as amoebas.
