Page 3 - Academic Press Encyclopedia of Physical Science and Technology 3rd Polymer

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Encyclopedia of Physical Science and Technology EN002C-64 May 19, 2001 20:39

Biopolymers

E. Ann MacGregor
University of Manitoba

I. General Characteristics of Polymers
II. Biopolymers

GLOSSARY Tertiary structure Overall folding of a polymer chain,
including relative orientations of secondary structures.
α-Amino acid Chemical compound containing a car-
boxylic acid group (COOH) and an amino group (NH 2 )
attached to one carbon atom. A POLYMER is a chemical substance whose molecules
Anomers Carbohydrates differing only in configuration are large and consist of many small repeating units cova-
of substituent groups at carbon 1 of an aldose sugar. lently bonded together. In nature, a wide variety of poly-
Configuration Arrangement of atoms in a molecule mers, the biopolymers, are synthesized by living organ-
in space.One configuration cannot be changed to isms. Among such biopolymers are the proteins which
another without breaking interatomic bonds in the perform many different functions, such as acting as cat-
molecule. alysts or regulators, the polysaccharides—important in
Conformation Arrangement of the atoms of a molecule structures and as energy reserves—and the nucleic acids
in space, which can be changed by rotation of chemical which carry genetic information from one generation to
groupings around single bonds in the molecule. the next. In addition, rubber, a plant polymer, is an in-
Covalent bond Bond between two atoms in which each dustrially important elastomer, while little direct com-
atom contributes one electron to the bonding. mercial use has yet been found for lignin, another abun-
Dalton Unitofatomicmass,equalto1.66053 × 10 −27 kg. dant plant polymer. The microbial polyesters, polyhydrox-
Gel Semisolid jelly of solid dispersed in liquid. yalkanoates, are, in contrast, growing in importance as
Hydrogen bond Weak bond formed when a hydrogen biodegradable plastics made from renewable resources.
atom is shared between two electron-attracting atoms
such as oxygen or nitrogen.
Primary structure Sequence of monomer residues in a I. GENERAL CHARACTERISTICS
polymer chain. OF POLYMERS
Quaternary structure Arrangement of subunits of a
polymer molecule in space (especially for pro- Polymer molecules, or macromolecules, are composed of
teins).Each subunit must itself be a polymer chain. large numbers of linked, small repeat units. The units from
Secondarystructure Regularfoldingofapolymerchain, which polymers are synthesized are called monomers.
stabilized by hydrogen bonding. Polymers may be made from one kind of monomer, giving

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