Glossary
Apoptosis is the
programmed death of cells. It is a mechanism of the
organism to maintain a relative constant and normal
number of cells. It also includes a cascade of
biological processes that result to the death of a
cell, when it is seriously damaged or infected by a
virus.
Adipocyte is the main type
of cells that compose adipose tissue and are also
known as fat cells, or lipocytes. Their main
function is to store energy in the form of fat.
Allele is one member of
the pair that makes up a gene. Genes come in pairs
and each allele is an alternative form of the gene.
Amino acids are components
of proteins. Some are synthesized by the body
(nonessential amino acids) and others must be
obtained through diet (essential amino acids).
Antioxidant is a substance
that can protect the cells from damages caused by
conditions of oxidative stress.
β (beta)-pancreatic
cells are a type of cells in pancreas which are
responsible for the production and secretion of
insulin.
BMD (Bone Mineral Density)
is a measure of bone density. BMD test is used to
define loss of bone mass and detect osteoporosis.
BMI (Body Mass Index)
is a statistical measurement, used to estimate
whether individuals have normal body weight. It
compares weight and height based on the mathematic
formula: BMI= mass (kg)/ height˛ (m˛).
Carcinogen is an agent
(substance or radiation) that is involved in the
development of cancer. Carcinogens can cause serious
damage either to the DNA or the metabolic functions
of cells.
Detoxification is the
process of removing or inactivating toxic substances
from the body. It is crucial for cells to maintain
their ability to detoxify themselves from
substances, which have the potential to cause
serious damages.
DNA is a large molecule
found in the nucleus of the cell. It contains the
essential genetic information for the function of
living organisms and has a significant role in the
development of all traits that define our
individuality. Its molecular structure in place has
the shape of a double spiral, called double helix.
DNA sequence is a
succession of nucleotides in the DNA molecule.
DNA testing utilizes
techniques that enable scientists to define the DNA
sequence or detect certain nucleotides at specific
positions of the DNA.
Carbohydrate is a compound
of carbon, hydrogen and oxygen. It is an important
source of energy found in food.
Cell is the smallest
functioning unit in the structure of an organism. It
is enclosed by a membrane and contains a nucleus and
organelles with certain functions (mitochondria,
lysosomes, ribosomes).
Cell cycle is the series
of events that result to cell division and cell
proliferation. A process very important for
development, growth, wound healing.
Cholesterol is a waxy,
fat-like substance essential for the structure of
cell membrane. It is also a component of certain
hormones and some Vitamins and is transported with
lipoproteins through blood circulation.
Chromosome is a rod-shaped
compound of DNA and proteins found in a cell
nucleus. The structure serves the DNA package in the
nucleus and the control of DNA functions. A human
body cell normally contains 46 chromosomes arranged
in 23 pairs.
Chromatin is the
combination of DNA and proteins which when condensed
makes up chromosomes.
Enzyme is a protein that
controls biochemical reactions, resulting to either
production or inactivation of substances in cells.
Genes represent small
segments of the DNA molecule which are the
structural units of heredity in all living
organisms. They contain the genetic information
which can be used by cells. The human genome
contains approximately 30,000 genes, which are
located at specific positions on chromosomes.
Genetic profile results
from analysis of several genes in the DNA of an
individual. It can be informative for the genetic
tendencies of individuals regarding the trait under
consideration.
Genotype describes the
constitution of gene (the type of the gene). It
refers each time to a specific gene under
investigation, describing the alleles that the gene
contains. It often refers to the pair of the
nucleotides found at a specific position of the DNA
sequence.
Genome is the total
genetic material of a cell. It is the full
complement of genetic information that an organism
inherits from parents.
Glucose is a very
important carbohydrate in biological systems. It is
used by cells as a source of energy and is also an
intermediate of metabolism.
HDL (High Density Lipoprotein)
transports lipids through blood circulation. Due
to its ability to remove cholesterol from arteries
to liver and prevent serious damages, it is also
called ‘good cholesterol’.
Homeostasis is a state of
equilibrium (balance) or the tendency to reach
equilibrium. It is the ability of a living organism
to regulate its internal environment in order to
maintain a stable condition.
Homocysteine is an amino
acid, important for the production of another amino
acid called Cysteine. Homocysteine metabolism and
maintenance of normal levels is crucial for the
health, as elevated homocysteine levels in blood
associate primarily with problems of the
cardiovascular system.
HR max (Heart Rate max) is
the maximal number of heartbeats per unit of time.
It should be estimated by specialized medical staff
before an individual begins an exercise training
program.
HR reserve (Heart Rate
reserve) describes the difference between a
person’s HR max and resting Heart rate (heart beats
during resting). It is used in some cases of
measuring the intensity of physical exercise.
Immune response is the
response of the immune system: the mechanism
activated to defend against foreign harmful
substances that come into the body, pathogens, and
tumor cells.
Inflammation is a process
by which the body activates certain types of cells
to protect us from infections and substances
recognized as foreign.
Insulin is a hormone
produced in pancreas. It causes cells of fat tissue,
liver and muscle to take up glucose from blood and
use it as energy source.
LDL (Low Density Lipoprotein)
transports lipids through blood circulation.
LDL is often called ‘bad cholesterol’ as elevated
LDL levels are harmful for the cardiovascular
system.
Lipid is a molecule
naturally produced in the body with the main role of
energy storage. Certain types of lipids are
obtainedthrough diet from fats contained in food.
With lipid metabolism, the body synthesizes or
degrades the fats to produce lipids with the
essential characteristics. Triglycerides and fatty
acids belong to lipids.
Lipoprotein is a compound
of lipid and protein which transport lipids (fats)
and cholesterol around the body through blood
circulation. HDL, LDL, and VLDL
belong to lipoproteins.
Metabolism is a group of
chemical reactions that take place in a living
organism to maintain life, develop and reproduce. It
includes the processes of constructing components of
cells (anabolism) and breaking down compounds
(catabolism) to produce energy.
Molecule is the smallest
part of a chemical compound which can exist
independently. It consists of one or more atoms held
together by chemical forces.
Mutagen is an agent which
can cause a change in the genetic material of an
organism.
Mutation is a change in
the genetic material of an organism. Regarding human
cells, mutation refers to a change in the sequence
of the DNA. Mutations are responsible to a
significant degree for the variability of
characteristics observed in the human population.
Mutations can be beneficial, harmful or even
neutral, having no effect. They result to different
forms of alleles in genes, and are often called
polymorphisms. The effect of mutations is often
affected by environmental factors.
Nucleotides are the
structural molecules of the genetic material. In DNA
each nucleotide is represented by a letter, which
can be A, T, C, or G, each defined by the base that
the nucleotide contains (Adenine, Thymine, Cytosine,
or Guanine). When they are joined together and based
on their succession, nucleotides define certain
genetic information.
Oxidative stress is caused
in cells due to their reduced ability to fight
against oxidative factors, which are substances like
peroxides and free radicals. These can be either
by-products of normal functions of cells or can be
produced by environmental toxic substances when they
enter the body. In both cases they can have toxic
effects as they can damage seriously the components
of cells (proteins, lipids, DNA).
Pharmacogenomics is the
field of Pharmacology and Genetics, which
investigates how the DNA of individuals affects
their response to drugs. Based on DNA testing, it
aims to identify which drugs have increased efficacy
or cause reduced toxicity to an individual.
Predictive genomics is the
field of Medicine which identifies mutations in the
DNA of an individual in order to predict the
likelihood of this individual to develop certain
characteristics, abilities or conditions.
Proteins are molecules
made of amino acids. They are essential parts of
organisms and take part in energy metabolism.
Vitamin is a compound
necessary for an organism to function properly. A
compound is characterized as Vitamin, when it is
essential to be provided by diet as it cannot be
synthesized in adequate amounts by an organism.
VLDL (Very Low Density
Lipoprotein) transport lipids through blood
circulation.
VO2 max is the maximal
oxygen consumption, describing the amount of oxygen
transported and used during physical exercise of
individuals. It is an important factor for the
physical fitness.
Xenobiotic is a chemical
which can be found in an organism but it is not
normally produced by it nor obtained by diet. Drugs
and antibiotics are examples of xenobiotics.