-
Glossary
of Terms
This list of
key terms is taken from the glossary section of D. T. Zallen, Does
It Run in the Family? A Consumer's Guide to DNA Testing for Genetic
Disorders
For more information
on these terms, please see The
Science Behind the Genome Project or this Glossary
of Genetic Terms developed by the National Human Genome Research
Institute.
- cell:
The basic building block of all organisms. The human body is composed
of trillions of cells, specialized into many cell types including
muscle, nerve, blood, bone, and skin cells.
-
- chromosome:
A long ribbon-like structure containing collections of genes.
Each chromosome is a long thread of DNA. The standard number of
chromosomes in humans is forty-six.
-
complex disorder: A disorder attributed to a combination of
genetic and environmental factors. Cancer, heart disease, diabetes,
and many other common health problems fall into this category.
-
DNA: The abbreviation for deoxyribonucleic acid, the thread-like
molecule that is the genetic material. DNA the form of a double-stranded
helix. Each strand contains a long sequence of four types of chemical
bases (denoted as A, C, G, and T). The sequence of bases makes
up the genetic code containing the information for all of the
proteins that an organism produces. The helix is held together
by strand-to-strand bonds, following the chemical rule that A
connects to T, and G connects to C. DNA is located in the chromosomes
within the organism's cells.
-
enzyme protein: A type of protein whose function is to act
as a catalyst and make chemical reactions possible in living organisms.
In the absence of the enzyme, the chemical reaction for which
the enzyme is responsible will not take place.
-
gene: A defined section of DNA along the chromosome that encodes
information for the production of a particular protein necessary
for the functioning of the organism.
-
gene pair: The two genes, one derived from each parent, with
information for producing a protein. One gene comes from the chromosome
set contributed by the egg cell; the other gene from the chromosome
set contributed by the sperm cell. All genes come in pairs with
the exception of genes on the X chromosome in males. Males have
only one X chromosome, therefore the genes on the X chromosome
in males are present only in a single dose.
-
gene therapy: A means of treating or correcting genetic disorders
by introducing the normal or functioning gene into the cells of
individuals who lack the normal gene.
-
genetic counseling: A multifaceted interaction between a genetic
professional and a client in which information about individual
and family genetic risks are provided along with related information
about tests, treatments, and reproductive options.
-
genetic enhancement: The introduction of genes into the cells
of otherwise healthy individuals in order to provide these individuals
with new traits or features.
-
genome: The total genetic material contained in a full set
of chromosomes of an organism.
-
mutation: Any permanent change or alteration in the genetic
material (for example, in the DNA base sequence of a gene) that
changes the nature of the product made under the direction of
that gene.
-
nucleus: The place within the cell where the chromosomes are
contained. It is separated from the rest of the cell by a porous
membrane.
-
protein: A molecule composed of amino acids connected together
in a linear fashion. The order (sequence) of the amino acids in
a protein is determined by the order of bases found within the
DNA of a gene. (see enzyme protein and regulatory protein)
-
regulatory protein: Proteins that help control the activities
of genes or that integrate the different chemical processes which
occur in an organism.
-
sequence: The linear order of the bases in the DNA molecule
or of amino acids in a protein molecule.
-
single-gene disorder: A disorder which comes about when there
is a mutation in a specific gene, and one (for a dominant disorder)
or both (for a recessive disorder) of the genes in the gene pair
cannot function properly.
-
structural protein: A type of protein whose function is to
provide shape and support to the various parts of the organism
|
