Page 415 - Carrahers_Polymer_Chemistry,_Eighth_Edition

378 Carraher’s Polymer Chemistry

Protein: Polyamide in which the building blocks are alpha-amino acids joined by peptide
(amide) linkages.
Purine base: Compounds consisting of two fused heterocyclic rings, namely a pyrimidine and
an imidazole ring; essential part of nucleic acids.
Pyrimidine: A 1,3-diazine; essential part of nucleic acids.
Recombination: Enzymatic process whereby the linear arrangement of nucleic acid sequences
in a chromosome is altered by cleavage and rejoining.
Recycling codes: designations that allow easy, quick identification of a number of plastics

used in the manufacture of containers
Replication: Term used to describe duplication such as the duplication of DNA.
Repressor: Molecule, protein that binds to the regulatory sequence or operator for a gene
blocking its transcription.
Ribosomal RNA, rRNA: Class of RNA that serve as components of ribosomes.
Ribosome: Very large complex of rRNAs and proteins—very large; site of protein synthesis.
Ribonucleic acid (RNA): Nucleic acid in which ribose units are present. Essential units of life
and replication.
Secondary structure: Term used to describe the conformation of a protein molecule such as
a helix.
Silent mutation: Mutation in a gene that causes no delectable change in the biological func-
tioning of the gene.
Somatic cells: All body cells except germline cells; germline cells are cells that develop into
gametes—that is, egg or sperm cells.
Spliceosome: Large protein-RNA complex that splices mRNA allowing for a great complex-
icity in synthesized proteins.
Sticky ends: Two DNA ends in the same or different DNA with short overhanging single-
stranded segments that are complementary to one another helping the joining the two sites.
Structural gene: Gene coding for a protein or RNA as distinct from regulatory genes.
Template: Pattern or surface upon which mirror-image replication can occur.
Tertiary structure: Term used to describe the shape or folding of a protein.
Transcription: Enzymatic process where genetic information contained in one strand of DNA
is employed to make a complementary sequence of bases in an mRNA.
Transfer RNA, tRNA: Class of RNS each of which combine covalently with a specifi c amino
acid as the initial step in protein synthesis.
Translation: Process where the genetic information present in mRNA specifi es the sequence
of amino acids within a protein synthesis.
Transposons: Segments of DNA, found in almost all cells, that move or “hop” from one place
on a chromosome to another on the same or different chromosome.
Transposition: Movement of one gene or set of genes form one site in the genome to another
site.
Transcription: Term used to describe the transfer of information from DNA to RNA.
Translation: Term used to describe the transfer of information from RNA to protein
synthesis.
Virus: Self-replicating nucleic acid–protein complex that requires an intact host cell for repli-
cation; its genome can be either DNA or RNA.
Zwitterion: Dipolar ion of an amino acid.

EXERCISES
1. Define a protein in polymer science language.

2. Which α-amino acid does not belong to the L-series of amino acids?

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