assembler:
A device for molecular manufacturing that is able to guide chemical
reactions by positioning molecules.
association constant (Ka):
Measure of the association of a complex. For the binding equilibrium
A+B
AB, the association constant is given by [AB] / [A] [B], and it
is larger the tighter the binding between A and B. (See also dissociation
constant.)
aster:
Star-shaped system of microtubules emanating from a centrosome
or from a pole of a mitotic spindle.
astrocyte:
Category of glial cell in the central nervous system that typically
possesses long radial processes. Provides structural support to
nerve cells and helps control their chemical and ionic extracellular
environment.
atom:
The smallest unit of a chemical element. It is several Ångstrom
in diameter.
ATP (adenosine 5'-triphosphate):
Nucleoside triphosphate composed of adenine, ribose, and three
phosphate groups that is the principal carrier of chemical energy
in cells. The terminal phosphate groups are highly reactive in
the sense that their hydrolysis, or transfer to another molecule,
takes place with release of a large amount of free energy.
ATP synthase:
Enzyme complex in the inner membrane of the mitochondrion and
the thylakoid membrane of a chloroplast that catalyzes the formation
of ATP from ADP and inorganic phosphate during oxidative phosphorylation
and photosynthesis, respectively. Also present in the plasma membrane
of bacteria.
ATPase:
One of a large class of enzymes that catalyze a process that involves
the hydrolysis of ATP.
Parts of the glossary are from the following book:
Copyright 1983, 1989, 1994 From "Molecular Biology of the Cell" by
Bruce Alberts, Dennis Bray, Julian Lewis, Martin Raff, Keith Roberts,
James D. Watson. Reproduced by permission of Routledge, Inc., part of
The Taylor & Francis Group.
AB, the association constant is given by [AB] / [A] [B], and it
is larger the tighter the binding between A and B. (See also 