biotech ch 4

chromatin

nuclear DNA and proteins

gene

a section of DNA on a chromosome that contains the genetic code of a protein

nitrogenous base

an important component of nucleic acids (DNA and RNA)

base pair

the two nitrogenous bases that are connected by a hydrogen bond; for example

phosphodiester bond

a bond that is responsible for the polymerization of nucleic acids by linking sugars and phosphates of adjacent nucleotides

hydrogen bond

a type of weak bond that involves the "sandwiching" of a hydrogen atom between two fluorine

pyrimidine

a nitrogenous base composed of a single carbon ring; a component of DNA nucleotides

purine

a nitrogenous base composed of a double carbon ring; a component of DNA nucleotides

medium

a suspension or gel that provides the nutrients (salts

lysis

the breakdown or rupture of cells

R plasmid

a type of plasmid that contains a gene for antibiotic resistance

antiparallel

a reference to the observation that strands on DNA double helix have their nucleotides oriented in the opposite direction to one another

semiconservative replication

a form of replication in which each original strand of DNA acts as a template

transformed

the cells that have taken up foreign DNA and started expressing the genes on the newly acquired DNA

vector

a piece of DNA that carries one or more genes into a cell; usually circular as in plasmid vectors

operon

a section of prokaryotic DNA consisting of one or more genes and their controlling elements

RNA polymerase

an enzyme that catalyzes the synthesis of complementary RNA strands from a given DNA strand

promoter

the region at the beginning of a gene where RNA polymerase binds; the promoter "promotes" the recruitment of RNA polymerase and other factors required for transcription

operator

a region on an operon that can either turn on or off expression of a set of genes depending on the binding of a regulatory molecule

beta-galactosidase

an enzyme that catalyzes the conversion of lactose into monosaccharides

broth

a liquid media used for growing cells

agar

a solid media used for growing bacteria

media preparation

the process of combining and sterilizing ingredients (salts

autoclave

an instrument that creates high temperature and high pressure to sterilize equipment and media

enhancer

a section of DNA that increases the expression of a gene

silencer

a section of DNA that decreases the expression of a gene

transcription factors

molecules that regulate gene expression by binding onto enhancer or silencer regions of DNA and causing an increase or decrease in transcription of RNA

intron

the region on a gene that is transcribed into an mRNA molecule but not expressed in a protein

exon

the region of a gene that directly codes for a protein; it is the region of the gene that is expressed

histones

the nuclear proteins that bind to chromosomal DNA and condense it into highly packed coils

nonpathogenic

not known to cause disease

bacteriophages

the viruses that infect bacteria

gene therapy

the process of treating a disease or disorder by replacing a dysfunctional gene with a functional one

site-specific mutagenesis

a technique that involves changing the genetic code of an organism (mutagenesis) in certain sections (site-specific) of the genome

gel electrophoresis

a process that uses electricity to separate charged molecules

agarose

a carbohydrate from seaweed that is widely used as a medium for horizontal gel electrophoresis

polyacrylamide

a polymer used as a gel material in vertical electrophoresis; used to separate smaller molecules

ethidium bromide

a DNA stain (indicator); glows orange when it is mixed with DNA and exposed to UV light; abbreviated EtBr

methylene blue

a staining dye/indicator that interacts with nucleic acid molecules and proteins

high through-put screening

the process of examining hundreds or thousands of samples for a particular activity