Experiment: Kimchi chemistry

acidic: An adjective for materials that contain acid. Acidic materials often are capable of dissolving away some minerals such as carbonate, or preventing their formation in the first place.

aerospace: A research field devoted to the study of Earth’s atmosphere and the space beyond or to aircraft that travel in the atmosphere and space.

agent: A person or thing (it can be a chemical or even a form of energy) that plays some role in getting something done.

anaerobic: Occurring in the absence of oxygen. Anaerobic reactions take place in oxygen-free locations.

astronaut: Someone trained to travel into space for research and exploration.

average: (in science) A term for the arithmetic mean, which is the sum of a group of numbers that is then divided by the size of the group.

bacteria: (singular: bacterium) Single-celled organisms. These dwell nearly everywhere on Earth, from the bottom of the sea to inside other living organisms (such as plants and animals). Bacteria are one of the three domains of life on Earth.

biochemical: (adj.) Referring to something made and used within living things.

carbohydrates: Any of a large group of compounds occurring in foods and living tissues, including sugars, starch and cellulose. They contain hydrogen and oxygen in the same ratio as water (2:1) and typically can be broken down in an animal’s body to release energy.

cell: (in biology) The smallest structural and functional unit of an organism. Typically too small to see with the unaided eye, it consists of a watery fluid surrounded by a membrane or wall. Depending on their size, animals are made of anywhere from thousands to trillions of cells. Most organisms, such as yeasts, molds, bacteria and some algae, are composed of only one cell.

chemical: A substance formed from two or more atoms that unite (bond) in a fixed proportion and structure. For example, water is a chemical made when two hydrogen atoms bond to one oxygen atom. Its chemical formula is H₂O. Chemical also can be an adjective to describe properties of materials that are the result of various reactions between different compounds.

concentration: (in chemistry) A measurement of how much of one substance has been dissolved into another.

data: Facts and/or statistics collected together for analysis but not necessarily organized in a way that gives them meaning. For digital information (the type stored by computers), those data typically are numbers stored in a binary code, portrayed as strings of zeros and ones.

diffusion: The process of spreading out thinly over a great area. It can involve the release or movement of light or some substance through a liquid (such as water or air) or through some surface (such as a membrane).

equation: In mathematics, the statement that two quantities are equal. In geometry, equations are often used to determine the shape of a curve or surface.

factor: Something that plays a role in a particular condition or event; a contributor.

fermentation: (v. ferment) The metabolic process of converting carbohydrates (sugars and starches) into short-chain fatty acids, gases or alcohol. Yeast and bacteria are central to the process of fermentation. Fermentation is a process used to liberate nutrients from food in the human gut. It also is an underlying process used to make alcoholic beverages, from wine and beer to stronger spirits.

flavor: The particular mix of sensations that help people recognize something that has passed through the mouth. This is based largely on how a food or drink is sensed by cells in the mouth. It also can be influenced, to some extent, by its smell, look or texture.

fungus: (plural: fungi) One of a group of single- or multiple-celled organisms that reproduce via spores and feed on living or decaying organic matter. Examples include mold, yeasts and mushrooms.

glucose: A simple sugar that is an important energy source in living organisms. As an energy source moving through the bloodstream, it is known as “blood sugar.” It is half of the molecule that makes up table sugar (also known as sucrose).

lactic acid: A chemical compound commonly found in milk and in exercising muscles.

liquid: A material that flows freely but keeps a constant volume, like water or oil.

membrane: A barrier which blocks the passage (or flow through) of some materials depending on their size or other features. Membranes are an integral part of filtration systems. Many serve that same function as the outer covering of cells or organs of a body.

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.

molecule: An electrically neutral group of atoms that represents the smallest possible amount of a chemical compound. Molecules can be made of single types of atoms or of different types. For example, the oxygen in the air is made of two oxygen atoms (O₂), but water is made of two hydrogen atoms and one oxygen atom (H₂O).

monitor: To test, sample or watch something, especially on a regular or ongoing basis.

organism: Any living thing, from elephants and plants to bacteria and other types of single-celled life.

osmosis: The movement of certain molecules within a solution across a membrane. The movement is always from the solution where the concentration of some chemical is higher to the solution where the concentration of that chemical is lower. This movement tends to continue until concentrations on each side of the membrane are the same.

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).

pH: A measure of a solution’s acidity or alkalinity. A pH of 7 is perfectly neutral. Acids have a pH lower than 7; the farther from 7, the stronger the acid. Alkaline solutions, called bases, have a pH higher than 7; again, the farther above 7, the stronger the base.

polyethylene: A plastic made from chemicals that have been refined (produced from) crude oil and/or natural gas. The most common plastic in the world, it is flexible and tough. It also can resist radiation.

range: The full extent or distribution of something. For instance, a plant or animal’s range is the area over which it naturally exists. (in math or for measurements) The extent to which values can vary (such as the highest to lowest temperatures). Also, the distance within which something can be reached or perceived.

salt: A compound made by combining an acid with a base (in a reaction that also creates water). The ocean contains many different salts — collectively called “sea salt.” Common table salt is a made of sodium and chlorine.

solution: A liquid in which one chemical has been dissolved into another.

synthesis: (v. synthesize) The production of a substance by the combining of simpler chemical building blocks.

taste: One of the basic properties the body uses to sense its environment, especially foods, using receptors (taste buds) on the tongue (and some other organs).

unique: Something that is unlike anything else; the only one of its kind.

yeast: One-celled fungi that can ferment carbohydrates (like sugars), producing carbon dioxide and alcohol. They also play a pivotal role in making many baked products rise.