Page 413 - Carrahers_Polymer_Chemistry,_Eighth_Edition

376 Carraher’s Polymer Chemistry

Active site-region of an enzyme or chromosome that binds the substrate molecule and cata-
lytically transforms it.
Alpha helix: Helical conformation of a chain, usually with maximal interchain hydrogen
bonding; one of the most common “natural” structures.
AluI: One of a family of restriction endonucleases that are site-specifi c endodeoxyribonu-
cleases that cause cleavage of both strands of DNA within or near a specific site recognized

by the enzyme; its recognition sequence is AG/CT.
Antibody: Defense protein synthesized by the immune system of vertebrates.

Anticodon: Specific sequence of three nucleotides in tRNA, complementary to a codon for an
amino acid in mRNA.
Antigen: Molecules capable of eliciting the synthesis of a specifi c antibody.
Attenuator: RNA sequence involved in regulating the expression of certain genes; also func-
tions as a transcription terminator.
Base pair: Two nucleotides in nucleic acid chains that are paired by hydrogen bonding of their
bases; like Gee-CAT representing the preferred pairing of G with C and A with T.
Chromosome: Single large DNA molecule and its associated proteins that contains many
genes. It stores and transmits genetic information.
Centromere: Specialized site within a chromosome that serves as the attachment point for the
mitotic or meiotic spindle during cell division that allows proteins to link to the chromo-
some. This attachment is essential for the equal and orderly distribution of chromosomes
sets to daughter cells. It is about 130 base pairs in length and is rich in A=T pairs.
Clones: Descendants of a single cell.
Cloning: Production of large numbers of identical DNA molecules, cells, or organisms from
a single ancestral DNA molecule, cell, or organism.
Codon: Sequence of three adjacent nucleotides in a nucleic acid that codes for a specifi c
amino acid.
Cofactor: A coenzyme or other cofactor required for enzyme activity.
Collagen: Protein present in connective tissue.
Complementary: Molecular surfaces with chemical groups arranges to interact specifi cally
with the chemical groupings on another molecular surface or molecule.
Denaturation: Change in conformation of a protein resulting from heat or chemicals.
Denatured: Partial or complete unfolding of the specific native conformation of a polypeptide,

protein, or nucleic acid.

Degenerate code: Code where a single element in one language is specified by more than one
element in a second language.
Deoxyribonucleic acid: Nucleic acid in which deoxyribose unit are present; compose the
human genome.
Diploid: Having two sets of genetic information—such as a cell having two chromosomes of
each type.

DNA profi ling: Identification method based on variations between individual’s DNA.
Domain: Distinct structural unit of a polypeptide.
Elastin: Protein that is the major material of arterial blood vessels and ligaments that is noted
for its fl exibility.
Enhancers: DNA sequences that help the expression of a specifi c gene; may be located close
to or far from the particular gene.
Enzyme: Molecule, protein, or RNA that catalyzes a particular chemical reaction.
Engineering material: Material that can be machined, cut, drilled, sawed, and so on; must
have enough dimensional stability to allow these actions to be carried out on them.
Eukaryote: Unicellular or multicellular organism with cells having a membrane-bound
nucleus, several chromosomes, and internal organelles.

9/14/2010 3:41:27 PM
K10478.indb 376 9/14/2010 3:41:27 PM
K10478.indb 376