terms
What is polycistronic mRNA
single mRNA molecule that contains the coding information for more than one protein.
where does the regulator protein bind onto the operon
onto the operator
what does the lac operon encodes genes for
the metabolism of lactose
How do restriction enzymes recognize where to cut DNA?
They recognize specific palindromic sequences and cut at or near these sequences.
What are the three main steps of a PCR cycle?
Denaturation, annealing, and extension
What is the function of a regulator gene?
encodes a protein (usually a repressor or activator) that affects the transcription of another gene or operon.
what process is being regulated by the regulator protein
transcription
what are the structural genes
beta- galactosidase
permease
transacetlyase
what is a palindromic sequence
a sequence of base pairs that reads the same in both directions, when read 5' to 3' on one strand and 3' to 5' on the complementary strand.
What is the main principle behind gel electrophoresis?
separates DNA fragments based on their size, with smaller fragments moving faster through the gel.
What do structural genes encode?
Structural genes encode proteins or RNA involved in metabolism, structural functions, and biochemical pathways.
What is the default state of gene expression in a negative inducible operon?
"Off" (repressor bound to operator).
What protein does the lacY gene encode?
permease
How do sticky ends differ from blunt ends after a restriction enzyme cuts DNA?
Sticky ends have overhanging single-stranded DNA regions, which can pair with complementary sequences, while blunt ends have no overhang and result in straight cuts across both strands.
What is the role of the Cas9 protein in CRISPR-Cas9 gene editing
an enzyme that cuts DNA at a specific location guided by RNA.
What is meant by "constitutive expression" of a gene?
refers to genes that are continuously expressed under normal cellular conditions without regulation.
What happens when an inducer binds to the repressor in a negative inducible operon?
It inactivates the repressor, allowing transcription.
What happens if the lacO gene is functional (lacO+) in the lac operon?
Repressor can bind to this operator in the absence of the inducer
how to calculate the probability a particular RE recognition site would occur by chance within a piece of DNA?
(1/4) to the power of number of bp postitions
what sequence does Cas9 nuclease cut upstream of
PAM sequence
Explain the difference between positive and negative control in gene regulation
Positive control involves the activation of gene expression by an activator protein, while negative control involves the inhibition of gene expression by a repressor protein.
What is the role of a corepressor in a negative repressible operon?
It activates the repressor to block transcription.
if the genotype of the lac operon is
lacI+ lacP+ lacO+ lacZ+ lacY+, with lactose absent what us the resent
transcription does not occur, not structural proteins produces
how to calculate the amount of recognition sites in a DNA sequence
divide the amount of base pairs in the sequence by the amount of base pairs at one site.
ex.
1000 bp x 1 site / 256 bp = 4 sites
what is the result of non-homologous end joining in CRISPR-Cas9
duplication or deletion