Chapter 6 Vocab

genome

entire set of DNA instructions found in cell

gene

unit of heredity transferred parent to offspring

genotype

genetic characteristics

phenotype

physical characteristics

antiparallel

strands run in opposite directions

semiconservative

during DNA replication, 2 strands of nucleotides separate

helicase

unwinds DNA

ligase

“glue” DNA fragments together

DNA polymerase I

removing RNA primers

DNA polymerase III

add nucleotides to the 3’ end of growing

RNA primer

provides 3’ end onto which polymerase can add nucleotides

SSB proteins

binds to single stranded regions of DNA (in e. coli)

replication fork

where the parent DNA strands split

leading strand

continuously synthesized strand

lagging strand

replicates discontinuously forming short fragments

okazaki fragments

short lwngths of DNA on lagging strand

topoisomerase IV

bacterial enzyme unlinks and resolves DNA knots

transcription

DNA→RNA

translation

mRNA → amino acids

polyribosome complex

mRNAs with multiple ribosomes attached

mRNA

carries the genetic info to make proteins

tRNA

decodes mRNA sequence into protein

rRNA

links amino acids together

promoter

where RNA polymerase begins transcriptions

exons

region of genome that ends up in mRNA

introns

noncoding sections that get spliced out

repressible operons

transcription of gene is repressedi

inducible operons

gene can be turned on by presence

phase variation

reversible switch on/off expressing phase

vertical gene transfer

parent to offspring (binary fission)

horizontal gene transfer

acquire DNA not from parent cell

transformation

foreign genetic material is taken up by cell

transduction

virus transfers genetic material from one to another

bacteriophage

virus that infects bacteria

mutations

change in DNA sequencemutag

mutagens

chemical/physical agent that induces mutations