BioScience Dictionary

 
A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z | Ot.

Found Cell 1460 times.

Displaying results 1 to 10.

1. -ase
A suffix which indicates that the word is the name of an enzyme , which is a type of protein that catalyzes biological or biochemical reactions. For example, " cellulase " or " polymerase ".

2. 5-fluorodeoxyuridine
An anti- cancer agent derived from 5-fluorouracil which forms in cells that have been treated by 5-fluorouracil.

3. 5-fluorouracil (5-FU)
An anti- cancer agent similar in structure to the nitrogenous base thymine , which inhibits the enzyme dihydrofolate reductase (DHFR) and thus nucleotide synthesis, so that it is particularly harmful to rapidly growing cells such as in tumors .

4. Abiotrophy
Premature loss of a cell's or tissue's ability to function.

5. Abnormal hemoglobin
Hemoglobin molecule with a different shape due to an altered amino acid sequence (ultimately caused by an altered DNA base sequence), such as in the inherited disease sickle-cell anemia .

6. ABO blood group (blood type, blood typing)
A system of describing the oligosaccharide antigen s found on the surface of human blood cells. According to the type of antigen present, a person may be assigned a blood type of A, B, AB or O. A second type of antigen, the Rh factor , renders a "positive" or "negative" blood type. The ABO blood group system is important because it determines who can donate blood to or accept blood from whom. Type A or AB blood will cause an immune reaction in people with type B blood, and type B and AB blood will cause a reaction in people with type A blood. Conversely, type O blood has no A or B antigens, so people with type O blood are "universal donors." And since AB blood already produces both antigens, people who are type AB can accept any of the other blood types without suffering an immune reaction. The ABO system is also important because it can be used in paternity suits to rule out whether a man is the father of a certain child or not.

7. Abscisic acid (ABA, abscisin)
A lipid hormone that inhibits cell growth in plants; it is associated with fruit drop, leaf death and seed dormancy. It is synthesized in the plastid s from carotenoid s. This hormone helps plants deal with water loss, and its effects can be reversed with gibberellin s.

8. Absorbance (optical density)
This is a measure of the amount of light absorbed by a suspension of bacterial cells or a solution of an organic molecule; it is measured by a colorimeter or spectrophotometer . Absorbance values are used to plot the growth of bacteria in suspension culture s and to gauge the purity and concentration of molecules (such as proteins) in solution. Absorbance is defined as a logarithmic function of the percent transmission of a wavelength of light through a liquid.

9. Absorption
The process of absorbing; specifically: * In physiology, it refers to the movement of liquids and solute s into cells by way of diffusion or osmosis. * In chemistry, it refers to the drawing of a gas or liquid into the pores of a permeable solid. * In immunology, it refers to a process in which an antigen or antibody is used to pull an analogous antigen or antibody out of a solution. Compare adsorption .

10. Absorption
The process by which the products of digestion are transferred into the body's internal environment, enabling them to reach the cells.


View web definitions »

Learn more about Cell »