GeroNova Glossary of Terms
Amino Acids - Organic (carbon-containing) molecules that serve as the building blocks of proteins.
Antioxidant - Any substance that prevents or reduces damage caused by reactive oxygen species (ROS) or reactive nitrogen species (RNS). ROS and RNS are highly reactive chemicals that attack other molecules and modify their chemical structure. Antioxidants are commonly added to foods to prevent or delay their deterioration due to exposure to air.
Apoptosis - Gene-directed cell death or programmed cell death that occurs when age, condition, or state of cell health dictates. Cells that die by apoptosis do not usually elicit the inflammatory responses that are associated with necrosis. Cancer cells are resistant to apoptosis.
Atherosclerosis - Also known as arteriosclerosis, atherosclerosis results from the accumulation of cholesterol-laden plaque in artery walls. Plaque accumulation causes a narrowing and a loss of elasticity of the arteries, sometimes referred to as hardening of the arteries.
ATP - Adenosine triphosphate. An important compound for the storage of energy in cells, as well as the synthesis (formation) of nucleic acids.
Autoimmune Disease - Autoimmune diseases occur when the body tissues are mistakenly attacked by its own immune system. The immune system is a complex organization of cells and antibodies designed normally to destroy pathogens, particularly viruses and bacteria that cause infections. Individuals with autoimmune diseases have antibodies in their blood which target their own body tissues.
Blood-Brain Barrier - The blood brain barrier is a barrier of tightly packed cells that the body uses to protect the brain from chemicals and infections in the blood, while still allowing essential functions.
Carbohydrate - Considered a macronutrient because carbohydrates provide a significant source of calories (energy) in the diet. Chemically, carbohydrates are neutral compounds composed of carbon, hydrogen and oxygen. Carbohydrates come in simple forms known as sugars and complex forms, such as starches and fiber.
Cardiovascular - Referring to the heart and blood vessels.
Cardiovascular Diseases - Literally, diseases affecting the heart and blood vessels. The term has come to encompass a number of conditions that result from atherosclerosis, including myocardial infarction (heart attack), congestive heart failure, and stroke.
Cell - The primary unit of physical life, whose integral structure and optimal status is crucial for the healthy functioning of the human body.
Cell Membrane - Also called the plasma membrane. The external limiting membrane of a cell. It is composed of lipids (fat molecules) that have a hydrophobic (insoluble in water) end and a hydrophilic (water-soluble) end. Cell membranes are made of lipid bilayers in which the lipids line up in two layers with the hydrophobic ends facing each other and the hydrophilic ends facing the outside and the inside of the cell.
Cell Signaling - Communication among individual cells so as to coordinate their behavior to benefit the organism as a whole. Cell-signaling systems elucidated in animal cells include cell-surface and intracellular receptor proteins, protein kinases and protein phosphatases (enzymes that phosphorylate and dephosphorylate proteins), and GTP-binding proteins.
Cholesterol - A lipid used in the construction of cell membranes and as a precursor in the synthesis of steroid hormones. Dietary cholesterol is obtained from animal sources, but cholesterol is also synthesized by the liver. Cholesterol is carried in the blood by lipoproteins (e.g., LDL and HDL). In atherosclerosis, cholesterol accumulates in plaques on the walls of some arteries.
Coenzyme - A molecule that binds to an enzyme and is essential for its activity, but is not permanently altered by the reaction. Many coenzymes are derived from vitamins.
Cofactor - A compound that is essential for the activity of an enzyme.
Cognitive - An adjective referring to the processes of thinking, learning, perception, awareness, and judgment.
Cytokine - A protein made by cells that affects the behavior of other cells. Cytokines act on specific cytokine receptors in the cells they affect.
Diabetes (Diabetes Mellitus) - A chronic condition associated with abnormally high levels of glucose (sugar) in the blood. The two types of diabetes are referred to as insulin-dependent (type 1) and non-insulin dependent (type 2). Type 1 diabetes results from a lack of adequate insulin secretion by the pancreas. Type 2 diabetes (also known as adult-onset diabetes) is characterized by an insensitivity of the tissues of the body to insulin secreted by the pancreas (insulin resistance).
Diabetic Ketoacidosis - A potentially life-threatening condition characterized by ketosis (elevated levels of ketone bodies in the blood) and acidosis (increased acidity of the blood). Ketoacidosis occurs when diabetes is not adequately controlled.
DNA - Deoxyribonucleic acid. A long thread-like molecule made up of large numbers of nucleotides. Nucleotides in DNA are composed of a nitrogen containing base, a 5-carbon sugar (deoxyribose), and phosphate groups. The sequence of bases in DNA serves as the carrier of genetic (hereditary) information.
Enzyme - A biological catalyst. That is, a substance that increases the speed of a chemical reaction without being changed in the overall process. Enzymes are vitally important to the regulation of the chemistry of cells and organisms.
Fatty Acid - An organic acid molecule consisting of a chain of carbon molecules and a carboxylic acid (COOH) group. Fatty acids are found in fats, oils, and as components of a number of essential lipids, such as phospholipids and triglycerides. Fatty acids can be burned by the body for energy.
Free Radical - A very reactive atom or molecule typically possessing a single unpaired electron.
Gene Expression - The full use of the information in a gene through transcription and translation leading to production of a protein.
Glucose - A 6-carbon sugar which plays a major role in the generation of energy for living organisms.
Glutathione - A small peptide consisting of three amino acids (glutamate -cysteine -glycine). It participates in redox reactions and is an important reducing agent inside cells.
GTP - Guanosine triposphate. A high energy molecule, required for a number of biochemical reactions, including nucleic acid and protein synthesis (formation).
IGF-1 - Literally, insulin-like growth factor 1, a crucial blood protein produced in the liver in response to stimulation by growth hormone. IGF-1 provides the best indicator of growth hormone levels and optimal levels are linked to healthy bone, heart, thyroid, skin, and nervous system.
Inflammation - A response to injury or infection, characterized by redness, heat, swelling, and pain. Physiologically, the inflammatory response involves a complex series of events, leading to the migration of white blood cells to the inflamed area.
Insoluble - Not dissolvable. With respect to bioavailability, certain substances form insoluble complexes that cannot be dissolved in digestive secretions, and therefore cannot be absorbed by the digestive tract.
Insulin - A peptide hormone secreted by the T-cells of the pancreas required for normal glucose metabolism.
Insulin Resistance - Diminished responsiveness to insulin.
In Vitro - Literally "in glass" referring to a test or research done in the test tube, outside a living organism.
In Vivo - "Inside a living organism". An in vivo assay evaluates a biological process occurring inside the body.
Ischemia - A low oxygen (hypoxic) state usually related to insufficient blood flow to a tissue.
Isomers - Compounds that have the same numbers and kinds of atoms but that differ in the way the atoms are arranged.
Ketone Bodies - Any of three acidic chemicals (acetate, acetoacetate, and beta-hydroxybutyrate). Ketone bodies may accumulate in the blood (ketosis) when the body has inadequate glucose to use for energy, and must increase the use of fat for fuel. Ketone bodies are acidic, and very high levels in the blood are toxic and may result in ketoacidosis.
Lipoic Acid - A cofactor, essential for the oxidation of alpha-keto acids, such as pyruvate, in metabolism.
Lipoproteins - Particles composed of lipids and protein, that allows for transport of fat and cholesterol through the blood. A lipoprotein particle is composed of an outer shell of phospholipid, which renders the particle soluble in water; a core of fats called lipid, including cholesterol and a surface apoprotein molecule that allows tissues to recognize and take up the particle.
Lp(a) Lipoprotein - A lipoprotein particle in which the protein (apolipoproteinB-100) is chemically linked to another protein apolipoprotein(a). Increased blood levels of Lp(a) are associated with an increased risk of cardiovascular diseases.
Mitochondria - Energy-producing structures within cells. Mitochondria possess two sets of membranes, a smooth continuous outer membrane, and an inner membrane arranged in folds. Among other critical functions, mitochondria convert nutrients into energy via the electron transport chain.
Multiple Sclerosis (MS) - An autoimmune disorder, which results in the demyelinization of nerves. In MS, the myelin shealth that allows for efficient transmission of nerve impulses is damaged, resulting in progressive neurological symptoms such as, numbness, tingling, loss of control of certain bodily functions, and paralysis.
Neuropathy - Malfunction or disease pathology of nerves. Peripheral neuropathy refers to a disease or degenerative state of peripheral nerves resulting in pain, numbness, and sometimes muscle weakness.
Nucleic Acids - DNA (deoxyribonucleic acid) and RNA (ribonucleic acid). Long thread-like molecules made up of large numbers of nucleotides. Nucleotides are composed of a nitrogen containing base, a 5-carbon sugar, and one or more phosphate groups. The sequence of bases in DNA or RNA represents the genetic (hereditary) information of a living cell.
Oxidation - A chemical reaction that removes electrons from an atom or molecule.
Oxidative Stress - An organism is said to experience oxidative stress when the effects of prooxidants (e.g. free radicals, reactive oxygen and reactive nitrogen species) exceed the ability of antioxidant systems to neutralize them.
Pancreas - A small organ located behind the stomach. The head of the pancreas is connected to the duodenum (the first section of the small intestine). The pancreas makes enzymes that help digest food in the small intestine and hormones, including insulin, that control the amount of glucose in the blood.
Pharmacodynamics (PD) - The effects of drugs on tissues and organs.
Peptide - A chain of amino acids. A protein is made up of one or more peptides.
Peripheral Neuropathy - A disease or degenerative state affecting the nerves of the extremities (arms and legs). Symptoms may include numbness, pain, and muscle weakness.
pH - A measure of acidity or alkalinity.
Pharmacokinetics (PK) - The study of the absorption, distribution, metabolism, and elimination of drugs.
Plasma - The liquid part of blood (as opposed to blood cells) that makes up about half its volume. Plasma differs from serum in that the blood sample has not clotted. A centrifuge is used to separate plasma from cells in the laboratory.
Potassium - Promotes regular heart rate. Promotes normal muscle contraction. Regulates transfer of nutrients to cells. Preserves or restores normal function of nerve cells, heart cells, skeletal-muscle cells, kidneys and stomach-juice secretions. Treats potassium deficiency due to illness or taking diuretics (water pills), cortisone drugs or digitalis preparations.
Prooxidant - An atom or molecule that promotes oxidation of another atom or molecule by accepting electrons. Examples of prooxidants include free radicals, reactive oxygen species (ROS) and reactive nitrogen species (RNS).
Protein - A complex organic molecule composed of amino acids in a specific order. The order is determined by the sequence of nucleic acids in a gene coding for the protein. Proteins are required for the structure, function, and regulation of the body's cells, tissues, and organs, and each protein has unique functions.
Reactive Oxygen Species (ROS) - Highly reactive chemicals, containing oxygen, that react easily with other molecules, resulting in potentially damaging modifications.
Receptor - A protein on or protruding from the cell surface to which select chemicals can bind. Binding of a specific molecule (ligand) may result in a cellular signal, or the internalization of the receptor and the ligand.
Redox Reaction - Another term for an oxidation-reduction reaction. A redox reaction is any reaction in which electrons are removed from one molecule or atom and transferred to another molecule or atom. In such a reaction one substance is oxidized (loses electrons) while the other is reduced (gains electrons).
Reduction - A chemical reaction in which a molecule or atom gains electrons.
RNA - Ribonuceic Acid. a chain of nucleotides, which are composed of a nitrogen containing base, a 5-carbon sugar (ribose), and phosphate groups. RNA functions in the translation of the genetic information in DNA to protein synthesis.
Supplement - A nutrient or phytochemical supplied in addition to that which is obtained in the diet.
Triglycerides - A triglyceride consists of three molecules of fatty acid combined with a molecule of the alcohol glycerol. Triglycerides serve as the backbone of many types of lipids (fats). Triglycerides are the major form of fat in our diets and are also produced by the body.