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biochemical reaction A biochemical reac- molecule always has more than one function; at
tion is any spontaneous or catalyzed transfor- a minimum it must be made and degraded.
mation of covalent or noncovalent molecular
bonds which occur in biological systems, written biometrics The field of study that uses
as a balanced, formal reaction equation, includ- mathematical and statistical tools to solve bio-
ing all participating molecular species, whose logical problems and solving mathematical and
kinetic order equals the sum of the partial orders statistical problems arising from biology. In
of the reactants, including the active form of any recent years, it has a much narrower meaning
catalyst(s). Equally, a composition of a set of in practice: it mainly deals with statistical analy-
bichemical reactions. sis and methodology applicable to biology and
Comment: The definition places no restric- medicine.
tions on the level of resolution of the description,
orsizeandcomplexityofreactingspecies; thus, it bipartite Describing a graph G(V, E)
permits the recursive specification of processes. whose chromatic number χ(G) = 2.
“Distinct origin” means molecular species aris- Comment: Informally, a graph will be bipar-
ing from different precursors. Thus, two pro- tite if it has two distinct sets of nodes and if nodes
tons, if one came from water and the other from of each type are always adjacent to the other.
a protein, would be individually recorded in the Thus the biochemical graph is bipartite because
equation. By “kinetic significance” is meant it has a set of compound nodes and a set of reac-
any molecular species which at any concentra- tive conjunction nodes, and each is connected to
tion contributes a term to the empirical rate law the other.
of the overall reaction. From the empirical rate
law, the reaction’s apparent kinetic order is the black hole (general relativity) A hypothet-
sum of the partial orders of the reactants (includ- ical object in space with so intense a gravitational
ing catalysts). The restriction to active forms field that light and matter cannot escape.
of the catalyst includes those instances where
blob See denser subgraph.
the catalyst must be activated, by either covalent
modification or ligand binding, or is inhibited by
block A portion of a macromolecule, com-
those means, so that not all molecules present
prising many constitutional units that has at least
are equally capable of catalysis. The definition
one feature which is not present in the adjacent
places no restrictions on the level of resolution of
portions. Where appropriate, definitions relating
the description, or size and complexity of reac-
ting species, thus permitting the recursive speci- to macromolecule may also be applied to block.
fication of processes. The recursion scales over
block matrix If a matrix is partitioned in
any size or complexity of process.
submatrices it is called a block matrix.
bioinformatics See computational biology.
Bogomolny equations The self-dual Yang-
Mills-Higgs equations are called Bogomolny
biological functions The roles a molecule
equations. They are
plays in an organism.
Comment: By function (called here biological 1
F = " F
function to distinguish it from the mathematical µν 2 µνρσ ρσ
sense of function), biologists mean both how 1
a molecule interacts with its milieu and what where F ab = " B ,F a4 = D φ, a, b, c =
2 abc
c
a
results from those interactions. The results 1, 2, 3. The solutions of the Bogomolny equa-
are often decomposed into biochemical, physio- tions are called magnetic monopoles.
logical, or genetic functions, but it is equally h 2
plausible to consider, for example, the ultrastruc- Bohr radius r B = 4π m e e 2 = 0.529 ×
2
tural function of a molecule (what part of the 10 −8 cm, where h is the Planck constant, m is
e
cell’s microanatomy does it build, how strong the rest mass of the electron, and e is the electron
is it, etc.). What is critical is to realize that a charge.

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