Mutations, Gene Expression Flashcards
point mutations
change in or loss of single base (or adding an extra one)
synonymous (silent) point mutation
codes for the same amino acid
missense point mutation
codes for the wrong amino acid
nonsense point mutation
codes for the stop codon
frameshift mutations
amino end of protein is normal, but the carboxyl end will be abnormal/truncated due to insertion or deletion of nucleotides
how can mutations in noncoding regions have effects?
could disrupt stop codon, promoter, terminator, splice sites, polyA site
non coding transcription units
non messenger RNA like tRNA, rRNA, snRNA, telomerase RNA; lack 5’ caps, can be mutations in these since they are from DNA
gene expression
most cells contain the same DNA but not all cells make (express) functional proteins from DNA
transcription factor
proteins that bind to specific nucleotide sequences in DNA which can increase or decrease transcription of nearby genes
lac-operon promoter
RNA polymerase
operator
repressor binds to lactose
CRP
enzyme/protein that binds to cAMP
cAMP
cAMP levels are high when lactose levels are high and glucose levels are low