T-cell

a type of white blood cell (LYMPHOCYTE) that forms in the bone marrow and moves to the thymus gland, situated in the thorax. There are a whole variety of T-cells involved in recognizing particular foreign bodies (ANTIGENS), and they are important in fighting viral infections and destroying bacteria that have penetrated the cells of the body.

Taken from Dictionary of Science

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T cells or T lymphocytes belong to a group of white blood cells known as lymphocytes, and play a central role in cell-mediated immunity. They can be distinguished from other lymphocyte types, such as B cells and natural killer cells by the presence of a special receptor on their cell surface called T cell receptors (TCR). The abbreviation T, in T cell, stands for thymus, since this is the principal organ responsible for the T cell's maturation. Several different subsets of T cells have been discovered, each with a distinct function.

Taken from Wikipedia

Tautomerism

a special case of structural isomerism, often called dynamic isomerism. It is when a compound exists as a mixture of two forms, or isomers (in equilibrium). The two forms can each change to the other as when, for example, one isomer is extracted from the mixture, then some of the other isomer will change to re-establish equilibrium. The ability to make this reversible change is due to a mobile atom or group, often hydrogen, which alters its position in the molecule possibly with the changing of a double bond. Isomers produced in this way are called TAUTOMERS and each can give rise to stable derivatives.

Taken from Dictionary of Science

Macrophage

a special type of cell that forms part of the IMMUNE SYSTEM of vertebrates. Macrophages are derived from MONOCYTES in the blood system and can move to infected or inflamed areas of the body using PSEUDOPODIA. In these areas, they surround, engulf and degrade broken cells and other debris, including microbes, by means of the process called PHAGOCYTOSIS.

Taken from Dictionary of Science

Water

hydrogen oxide (H20), a compound that is found everywhere. It can occur as solid, liquid and gas phases. It forms a very large part of the Earth's surface and is vital to life. It occurs in all living organisms and has a remarkable combination of properties in its solvent capacity, chemical stability, thermal properties and abundance.

Taken from Dictionary of Science

Tartaric Acid

an organic acid which exists in four forms that are STEREOISOMERS. The commonest form (d-tartaric acid) is used in dyeing, the manufacture of baking powder and "health salts". Another form (dl-tartaric acid, or racemic acid) occurs in grapes

Taken from Dictionary of Science

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Tartaric acid is a white crystalline diprotic organic acid. It occurs naturally in many plants, particularly grapes, bananas, and tamarinds, and is one of the main acids found in wine. It is added to other foods to give a sour taste, and is used as an antioxidant. Salts of tartaric acid are known as tartrates. It is a dihydroxy derivative of succinic acid.

Tartaric acid was first isolated from potassium tartrate, known to the ancients as tartar, c. 800 by the Persian alchemist Jabir ibn Hayyan, who was also responsible for numerous other basic chemical processes still in use today. The modern process was developed in 1769 by the Swedish chemist Carl Wilhelm Scheele. The chirality of tartaric acid was discovered in 1832 by Jean Baptiste Biot, who observed its ability to rotate polarized light. Louis Pasteur continued this research in 1847 by investigating the shapes of ammonium sodium tartrate crystals, which he found to be asymmetric. Pasteur was the first to produce a pure sample of levotartaric acid.

Taken from Wikipedia