SCIENCE TERMINOLOGY

BIOLOGY, CHEMICAL BIOLOGY, GENOMICS

Amino Acid
An organic compound containing an amino group, a carboxylic acid group, and any of various other groups that link together to form proteins or that function as chemical messengers in metabolism.

Atomic Mass Unit or Dalton
A unit of mass equal to one-twelfth the mass of carbon 12, the most abundant isotope.

Chromosome
Chromosomes carry the genes that determine the individual characteristics of an organism. Human body cells contain 46 chromosomes, 22 matched pairs and one pair of sex chromosomes.

Diploid
Having a pair of each type of chromosome, so that the basic chromosome number is doubled.

DNA (deoxyribonucleic acid)
DNA is the nucleic acid found inside the chromosomes of a cell’s nucleus that carries genetic information. It is made up of two long chains, called nucleotides, which are twisted together in a double helix. The sequence of the nucleotides determines individual hereditary characteristics.

Enzyme
A protein or group of proteins produced by living organisms that function as biochemical catalysts (a substance that modifies and increases the rate of a chemical reaction without being consumed in the process).

Free Radical
An atom or group of atoms that has at least one unpaired electron and is therefore unstable and highly reactive. In animal tissues, free radicals can damage cells and are believed to accelerate the progression of cancer, cardiovascular disease, and age-related diseases.

Gamete
A reproductive cell having a single set of chromosomes, especially a mature sperm or egg capable of fusing with a gamete of the opposite sex to produce a fertilized egg.

Gene
A gene is a short segment of DNA and the smallest unit of heredity. Information from all the body’s genes makes up a blueprint for the human body and its functions.

Genomics
The study of all of the nucleotide sequences in the chromosomes of an organism. A branch of biotechnology that applies the techniques of genetics and molecular biology to the genetic mapping and DNA sequencing of sets of genes or the complete genomes of selected organisms using high-speed methods. Results are organized into databases, and data is applied to fields such as medicine or biology.

Haploid
Having a single set of chromosomes.

Hydrolysis
The decomposition of a chemical compound by reaction with water, such as the conversion of starch to glucose

Intermediate molecule
A molecule weighing anywhere from 1,000 to 15,000 Daltons. These molecules may bind to disease-related proteins when small molecules cannot.

Ion
An atom or a group of atoms that has acquired a net electric charge by gaining or losing one or more electrons.

Ionic Bond
A chemical bond in which one atom loses an electron to form a positive ion and the other atom gains an electron to form a negative ion.

Meiosis
The process of cell division in sexually reproducing organisms that reduces the number of chromosomes in reproductive cells to a single set, leading to the production of gametes in animals and spores in plants.

Mitosis
The process in cell division by which the nucleus divides, typically consisting of four stages: prophase, metaphase, anaphase, and telophase. Normally, two new nuclei result, each of which contains a complete copy of the parental chromosomes.

Nucleotide
A compound that forms the basic constituent of DNA and RNA

Phosphate
An organic compound that permits useful energy to be released, such as in metabolism

Protein
Any of a group of complex organic macromolecules containing carbon, hydrogen, oxygen, nitrogen, and usually sulfur. Proteins are composed of one or more chains of amino acids.

Proteomics
A branch of biotechnology that applies the techniques of molecular biology, biochemistry, and genetics to analyzing the structure, function, and interactions of the proteins produced by the genes of a particular cell, tissue, or organism. Information is then organized in databases and data are applied to an area such as medicine or biology.

RNA (ribonucleic acid)
RNA is a nucleic acid found in all living cells that helps to synthesize protein. Messenger RNA (mRNA) carries the genetic code from DNA to the specialized sites within the cell where proteins form.

Small molecule
A molecule weighing 500 Daltons or less. Small molecules are one-fiftieth to one-hundredth the size of most proteins, which means that they are able to bind to some proteins, changing their shape and activity.

Spore
A small, usually single-celled reproductive body produced by certain bacteria, fungi, algae, and nonflowering plants that is capable of growing into a new organism.

ENVIRONMENT, MICROBIAL SCIENCE, ORIGINS OF LIFE

Astrobiology
The branch of biology focused on the effects of outer space on living organisms and the search for extraterrestrial life.

Astrophysics
The branch of astronomy focused on the physics of stellar phenomena.

Bacteria
Any of the single-celled prokaryotic microorganisms that vary in structure, oxygen and nutritional requirements, and movement. Bacteria may be free-living or nourished by dead or decaying matter, and are capable of causing disease in plants or animals.

Biodiversity
The number and variety of living organisms on the earth, including the variability within and between species and within and between ecosystems

Eukaryote
A single-celled or multicellular organism whose cells contain a distinct membrane-bound nucleus

Exoplanets
The planets and planetary systems around other stars.

Extremophiles
Organisms that thrive in extreme conditions, such as hot or cold habitats.

Geophysics
The study of the physics of the earth and its environment, including the physics of fields such as meteorology, oceanography, and seismology.

Isotope
One of two or more atoms that have the same atomic number (number of protons in the nucleus) but different mass numbers (the sum of the number of neutrons and protons in the nucleus).

Lithotroph
A cell or organism that depends on inorganic compounds for energy production

Microbe
A microorganism, especially disease causing bacteria

Prebiotic
The chemical or environmental material in existence before the origin of life.

Prokaryote
An organism characterized by the absence of a distinct, membrane-bound nucleus or membrane-bound organelles, and by DNA that is not organized into chromosomes

Tectonic
Pertaining to the structural deformation, or movement, of the earth’s crust.

NANOSCIENCE, PHYSICS

Atom
Atoms are the building blocks of matter, and all things are made of arrangements of atoms. We know of 118 different kinds of atoms because there are 118 different elements in the periodic table.

Molecule
Molecules are groups of atoms bonded together to create compounds.

Nanometer
A nanometer is one billionth of a meter, or approximately 3.5 atoms across on a gold surface. A human hair is approximately 100,000 nanometers, and a fingernail is more than 10 million nanometers thick.

Nanotechnology
Nanotechnology is an interdisciplinary, emerging area of engineering science that involves working with matter at the level of atoms and molecules and manufacturing small-scale devices.

String Theory
A hypothesis describing particles as tiny one-dimensional objects (strings) rather than zero-dimensional points. Because the strings are too small to be seen through current particle physics technology, string theorists must devise methods to test the theory.
Interest in string theory is driven largely by the hope that it will prove to be a theory of everything.

Theoretical Physics
Theoretical physicists use mathematics to describe certain aspects of nature. Sir Isaac Newton was the first theoretical physicist. In Newton’s time, algebra and geometry were used to build structures, such as cathedrals. But algebra and geometry describe only things that sit still, so Newton invented calculus to characterize things that move or change. Today’s theoretical physicists often work on the boundaries of known mathematics, sometimes inventing new mathematics. Theorists explore areas of nature in mathematics that current technology does not allow us to observe in experiments.

Quantum Gravity
Quantum gravity is the field of theoretical physics that attempts to unify the theory of quantum mechanics, which describes three of the fundamental forces of nature (electromagnetism, the weak nuclear force, and the strong nuclear force) with the theory of the fourth fundamental force (gravity). The ultimate goal is a unified framework for all fundamental forces—namely, a theory of everything.

Quantum Mechanics
Quantum mechanics is concerned with the energy of atoms and particles. For example, Heisenberg’s Uncertainty Principle states that it is impossible to know the precise location of a particle and know its energy at the same time. As a result, physicists must rely on probability.

Quantum Theory/Physics
Quantum theory is a theory of physics based on the principle that matter and energy have the properties of both particles and waves.

NEUROSCIENCE

Axon
The long, threadlike part of a nerve cell that carries nerve impulses away from the body of the cell.

Cerebral Cortex
The part of the brain responsible for all forms of conscious experience, including thought, perception, emotion, planning, and motor activity coordination. The neurons on the outermost layer of the brain form the cerebral cortex.

Cerebrum
The part of the brain that processes sensation and coordinates activity. The cerebrum is made up of two nearly symmetrical halves, called hemispheres, whose outermost layer forms the cerebral cortex.

Dendrite
The branched extension of a nerve cell that transmits nerve impulses to the cell body.

fMRI
Functional Magnetic Resonance
Imaging is a new method of noninvasive brain scanning that produces higher-resolution images than Positron Emission Tomography (PET), which requires radioactive materials. fMRI measures brain activity by detecting the oxygenated blood that flows through activated neurons.

Hemispheres
In most people, the left hemisphere of the cerebrum is specialized for speech, writing, language, and calculation; the right hemisphere is often specialized for spatial abilities and pattern recognition.

Neuron
Also called a nerve cell, a neuron is an elongated, branched cell that conducts impulses through the nervous system. The brain contains approximately 100 billion neurons. Neurons can be as long as a meter or as short as a millimeter.

Neurotransmitter
A chemical substance, such as adrenaline or dopamine, that transmits impulses across the synapse from one nerve cell to the next.

Synapse
The junction between two neighboring nerve cells where the membranes of the two cells are in close contact. Impulses travel from the axon of one nerve cell to the dendrite of another. Most nerve cells have more than one synapse, as some impulses can travel as quickly as 278 miles an hour.

STEM CELLS

Adult Stem Cells
Stem cells found in some, but not all, mature tissues that can self-renew and give rise to other cell types from their tissue of origin, thereby producing a steady supply of new cells to maintain that tissue throughout life. In general, adult stem cells from one organ do not give rise to cell types from other organs.

Blastocyst
An early-stage embryo, before its implantation in a uterus. The blastocyst consists of a microscopic cluster of several hundred undifferentiated cells, from which embryonic stem cells can be derived.

Cord Blood Stem Cells
Stem cells that are recovered from the umbilical cord at the time of birth. These blood stem cells resemble the stem cells found in adult bone marrow, and are more like adult stem cells than embryonic stem cells.

Differentiation
The process whereby a stem cell loses its capacity for self-renewal and becomes a mature and specialized cell type.

Embryonic Stem Cells
Stem cells derived from a blastocyst that (unlike adult stem cells) can give rise to every cell type in every organ of the body. When these cells are cultured for a period of time, they become known as a cell “line” with specific characteristics that may differ from other embryonic stem cell lines.

Self-Renewal
The ability of a stem cell to divide and give rise to more stem cells with properties identical to the parent cell.

Somatic Nuclear Transfer or Therapeutic Cloning
A process by which a nucleus from a single cell is transferred into an unfertilized egg, allowing the egg to revert to an embryonic state and develop to the blastocyst stage. Embryonic stem cells derived from this blastocyst are genetically identical to the donor of the original nucleus.

Stem Cell Line
A stem cell line is a mass of cells descended from the original cell, sharing its genetic characteristics. Batches of cells can then be separated from the cell line and distributed to researchers.