Nanoscience – working small, thinking big
Glossary
antibody. A protein produced by the body’s immune system in response to a foreign substance (antigen). An antibody reacts specifically with the antigen that induced its formation and inactivates the antigen. Our bodies fight off an infection by producing antibodies.
atom. The fundamental unit of all matter consisting of a nucleus of protons and neutrons surrounded by orbiting electrons (or in the case of hydrogen, just one electron). For more information see Back to Basics: Atoms and molecules (Australian Academy of Science).
catalyst. A substance that increases the rate of a chemical reaction without actually undergoing any change itself.
ion channel. A protein-coated pore in a cell membrane that selectively regulates the diffusion of ions into and out of the cell. An ion channel switches between open and closed when the protein undergoes a conformational change. For more information see Ions cannot cross membranes (University of Washington, USA).
membrane. A thin, pliable sheet or layer. Biological membranes consist of a double layer of lipids – organic molecules that are not soluble in water – and associated proteins. Biological membranes are selectively permeable – not all molecules can pass through the membrane. For more information see Structure of plasma membranes (British Broadcasting Corporation, UK) and Cell membranes (Kimball's Biology Pages, USA).
molecule. The smallest unit of a chemical compound that can exist. It consists of two or more atoms held together by chemical bonds. Molecules can vary greatly in size and complexity.
nanotubes. Extremely small tubes made from pure carbon. For more information see IPE nanotube primer (Institut de Physique des Nanostructures, Switzerland).
nuclear magnetic resonance (NMR) spectroscopy. Nuclear magnetic resonance (NMR) spectroscopy provides information on the position of specific atoms within a molecule by using the magnetic properties of nuclei. For more information see Nuclear Magnetic Resonance Spectroscopy (University of Calgary, Canada).
scanning probe microscopy. Scanning probe microscopes (SPMs) pass a needle-like probe over the surface of a molecule and record an image of that surface. Different SPMs can not only map the topography but also determine the type of atoms and their thermal and magnetic properties. Scanning tunnelling microscopes and atomic force microscopes are types of SPMs. For more information see Scanning probe microscopy (SPM) (Missouri Botanical Garden, USA).
semiconductor wafer. A tiny complex of electronic components and their connections, produced in or on a small slice of material (like silicon). For more information see Semiconductor manufacturing: How a chip is made (Texas Instruments, USA).
wavelength. The distance between two adjacent wave crests. Visible light and X-rays are both electromagnetic waves and differ from each other only in the length of the wave. The wavelength of visible light ranges from 400 to 700 nanometres while the wavelength of X-rays ranges from about 0.01 to 10 nanometres. The relatively long wavelength of visible light sets the limit of how small an image it can produce. For more information see Electromagnetic radiation (Back to basics, Australian Academy of Science).
X-ray crystallography. X-ray crystallography involves firing X-rays through the crystal of a molecule to produce a diffraction pattern. This pattern provides information on the structure of that crystal. For example, X-ray crystallography helped scientists discover that the DNA molecule exists as a double helix. For more information see Introduction to crystallography (Matter, UK) and X-ray crystallography (The British Biophysical Society, UK).
Page updated March 2007.