Specific site recognized by antibodies.

(quantum mechanics) An expression that describes the wavefunction of a multifermionic system. It satisfies antisymmetry requirements, and consequently the Pauli exclusion principle, by changing sign upon exchange of two electrons (or other fermions).

Measure of function's local distortion.

In functional analysis, a branch of mathematics, it is sometimes possible to generalize the notion of the determinant of a square matrix of finite order (representing a linear transformation from a finite-dimensional vector space to itself) to the infinite-dimensional case of a linear operator S mapping a function space V to itself.

Measure of a matrix's invertibility.

(biology) A substance, present in an egg or blastomere, that determines the fate of those cells that inherit it during cleavage.

Specific antigenic site on antibody.

Determinant of matrix of inner products.