Biochemistry: Chapter 3

Front 1

Amino Acids

Back 1

alpha-amino-substituted carboxylic acids, the building blocks of proteins

Front 2

Isoelectric pH

Back 2

The pH at which a solute has no net electric charge and thus does not move in an electric field

Front 3

Peptide

Back 3

Two or more amino acids covalently joined by peptide bonds

Front 4

Protein

Back 4

A macromolecule composed of one or more polypeptide chains, each with a characteristic sequence of amino acids linked by peptide bonds

Front 5

Peptide Bond

Back 5

A substituted amide linkage between the alpha-amino group of one amino acid and the alpha-carboxyl group of another, with the elimination of the elements of water

Front 6

Oligopeptide

Back 6

A few amino acids joined by peptide bonds

Front 7

Polypeptide

Back 7

A long chain of amino acids linked by peptide bonds; the molecular weight is generally less than 10,000

Front 8

Oligometric Protein

Back 8

A multisubunit protein having two or more identical polypeptides chains

Front 9

Promoter

Back 9

A DNA sequence at which RNA polymerase may bind, leading to initiation of transcription

Front 10

Conjugated Protein

Back 10

A protein containing one or more prosthetic groups

Front 11

Prosthetic Group

Back 11

A metal ion or an organic compound (other than an amino acid) that is covalently bound to a protein and is essential to its activity

Front 12

Primary Structure

Back 12

A descrioption of the covalent backbone of a polymer (macromolecule), including the sequence of monomeric subunits and any interchain and intrachain covalent bonds

Front 13

Secondary Structure

Back 13

The residue-by-residue conformation of the backbone of a polymer

Front 14

Tertiary Stucture

Back 14

The 3D conformation of a polymer in its native fold

Front 15

Quaternary Structure

Back 15

The 3D structure of a multisubunit protein; particularly the manner inwhich the subunits fit together

Front 16

Fractionation

Back 16

The process of separating the proteins or other components of a complex molecular mix into fractions based on differences in their physical properties, such as size, net charge, and solubility; Ex: Dialysis-size of prots

Front 17

Column Chromotography

Back 17

A procedure that takes advantage of differences in protein charge, size, binding affinity, and other properties to separate two or more

Front 18

High-Performance Liquid Chromotography (HPLC)

Back 18

Chromatographic procedure, often conducted at relatively high pressures, using automated equipment that permits refined and highly reproducible profiles

Front 19

Electrophoresis

Back 19

Movement of charged solutes in response to an electrical field; often used to separate mixtures of ions, proteins, or nucleic acids

Front 20

Sodium Dodecyl Sulfate (SDS)

Back 20

A detergent that binds to most proteins-it is used in an electrophoretic method commonly employed for estimation of purity and molecular weight

Front 21

Isoelectric Focusing

Back 21

An electrophoretic method for separating macromolecules on the basis of their isoelectric pH

Front 22

Edman Degradation

Back 22

A procedure that labels and removes only the amino-terminal residue from a peptide, leaving all other peptide bonds intact

Front 23

Proteases

Back 23

Catalyze the hydrolytic cleavage of peptide bonds

Front 24

Lateral Gene Transfer

Back 24

The rare transfer of a gene or group of genes from one organism to another

Front 25

Homologous Proteins (Homologs)

Back 25

Proteins having sequences and functions similar in different species; Ex: the hemoglobins

Front 26

Paralog

Back 26

Two homologs present in the same species

Front 27

Ortholog

Back 27

Genes in different organisms that possess a clear sequence and functional relationship to each other

Front 28

Signature Sequence

Back 28

One of many biochemical clues that can help establish evolutionary relatedness