BIMM 120 CH 8
bacterial RNA polymerase holoenzyme is composed of?
: required for elongation phase
: required for initiation
sigma factors help detect ____
where are the consensus sequences for sigma-70
-35 and -10
One way to measure level of gene expression?
how do sigma factors recognize specific DNA?
form fits function
RNA polymerase holoenzyme binds to the promoter
RNA chain is extended
RNA pol detaches from the DNA and releases RNA transcript
two types of termination signals
: relies on protein rho and strong pause after stop codon
: GC rich region of RNA that forms hairpin, 4-8 consecutive U residues
two fundamental criteria for antibiotics
kill or retard growth of pathogen
must not harm the host
selectively binds to bacterial RNA polymerase and inhibits transcription initiation
nonselectively binds to DNA
small RNA (sRNA)
regulates transcription or translation
frees ribosomes stuck on damaged mRNA
how is mRNA stability measured?
half-life of mRNA
how many possible codons?
64 (3 are stop codons)
T/F - Each tRNA must be charged with the proper amino acid after it encounters the ribosome.
how are tRNAs charged?
two subunits of ribosomes
30S and 50S to form 70S
what makes the peptide bonds that stitch amino acids
RBS that allows for proper reading frame
brings two ribosomal subunits together, placing first amino acid in position
adds amino acids
releases completed polypeptide and ribosomal subunits
two antibiotics that affect translation
streptomycin and tetracycline
what proteins help the folding of proteins?
protein degradation in bacteria
protein degradation in eukaryotes and archaea
how are proteins meant for cell membrane tagged? What are they bound by? What do they undergo?
N-terminal signal sequences
signal recognition particle (SRP)
pathway for protein export to periplasm
SecA-dependent general secretion pathway
Type 1 protein secretion
cytoplasm directly to extracellular environment
efflux ABC transporter
open reading frames (ORF)
sequence of DNA that encodes a polypeptide
orthologs vs paralogs
same function in different organisms
duplicated gene in different species with slightly different function
BIMM 120 CH 8