Chapter 15: Gene Regulation Pt. 1 Flashcards
how do bacteria respond to their environment?
metabolically
what are the two types of gene expression?
inducible and constitutive enzymes
what is an example of a repressible system?
tryptophan production in bacteria
inducible or repressible systems are regulated under
positive or negative control
negative control is present under a
repressible system (trp operon)
positive control is present under an
inducible system (lac operon)
what are the 3 structural genes of the lac Operon?
- lacZ
- lacY
- lacA
lacZ gene encodes for
B-galactosidase
B-galactosidase is an enzyme that converts lactose into
glucose and galactose
lacY gene encodes for
permease
permease facilitates entrance of
lactose into the bacteria cell
lacA gene encodes for
transacetylase
transacetylase is involved in the removal of…
toxic by-products from digestion of lactose
what is a cistron?
part of a nucleotide sequence coding for a single gene
structural genes of lac operon result in
polycistronic mRNA
merozygotes are
cells that are diploid for certain genes
CAP stands for
catabolite-activating protein
two characteristics of CAP
- helps activate expression of lac operon
- able to inhibit expression in presence of glucose
cAMP stands for
cyclic adenosine monophosphate
attenuation occurs in
leader sequence that contains attenuator sequence
antiterminator hairpin occurs in the absence of ______ between sections ______
tryptophan
2 and 3
terminator hairpin occurs…
in the presence of tryptophan
3 and 4
other forms of regulation involving RNA
- attenuation
- riboswitches
- small noncoding RNAs (sRNAs)
