Describe how the bacterial lac operon works
What is the energy of activation? Do endergonic
reactions possess an energy of activation? What about
exergonic reactions
What is the function of NADH & FADH2 in cell respiration
How do proteins & fats get incorporated into the cell
respiration pathway
In the fermentation pathway, why do we need to form lactic acid
even though no ATP is formed during this step?
The lac operon is regulated via positive and negative
regulation. Explain how each
mechanism works on this operon, and under which circumstances will
the operon be
turned on. Include the definition of an operon
2. What are the advantages to a microbe of having inducible
enzymes? What is the
function of toluene in the experiment where you induced enzyme
function?
Is the lac operon a repressible or an inducible operon? What
happens in the absence of lactose? What happens in the presence of
lactose? Is the trp operon a repressible or an inducible operon?
What happens in the absence of tryptophan? What happens in the
presence of tryptophan?
Is the lac operon a repressible or an inducible operon? What
happens in the absence of lactose? What happens in the presence of
lactose? Is the trp operon a repressible or an inducible operon?
What happens in the absence of tryptophan? What happens in the
presence of tryptophan?
1. For the lac operon, explain what would happen and why
regarding expression of the operon in each of the following
scenarios. Be sure to include both positive and negative regulation
in your explanation. a.) lactose is present, glucose is absent b.)
lactose is absent, glucose is present c.) both lactose and glucose
are present d.) lactose is present, glucose is absent, but there is
a mutation to the sequence in the CAP site
2.
The -10 core promoter of the lac operon gene has the sequence
TATGTT. Describe an example of a base substitution mutation which
would lead to increase transcription of the gene. Explain whether
this mutation would increase or decrease the fitness of the
organisms.
Discuss, in detail, catabolite repression in the Lac operon.
Indicate how this system is regulated
under various nutrient scenarios, all relevant components involved,
and how these components
interact.
Describe the likely effect on gene expression of a
mutation in the lac operon:
a) that delegate the operator
b) that mutates the lacI gene inactivating the repressor
c) that the promoter mutates in the -10 region