BioNB1200
Problem
Set
1
1. Sigmoid Kinetics are often associated with enzymes with _______?
a.) single substrate-binding sites
b.) multiple substrate binding sites
c.) low substrate affinity
d.) high substrate affinity
e.) an allosteric binding site
2. Which of the following answers does not accurately compare cell membranes to
epithelial cells?
a.
both create a barrier between the outside and inside environments
b.
both are composed of different forms of their components (i.e.
phospholipids or cells
c.
cell membranes are fluid with their components moving freely, while
epithelial cells are stationary
d. for a molecule to enter the inside environment formed by a cell membrane
it must only pass one membrane whereas for a molecule to enter the inside
environment formed by epithelial cells, it must pass through two
membrane
3. You have been doing an experiment to test the reaction velocity of a certain
enzyme, Enzyme A, at different substrate concentrations. You leave your lab and
return the next day to find that Dr. Catalyst, a rival scientist, has broken into your
lab! Nothing appears to be missing, but when you run your tests for the day at
different substrate concentrations, you discover that the velocity of the reaction
catalyzed by Enzyme A increases more slowly than it normally would. The
reaction velocity eventually reaches its normal maximum, but you suspect foul
play nonetheless. You assume that you have done nothing wrong and suspect Dr.
Catalyst may have sabotaged your assay. Based on the results what do you think
Dr. Catalyst did to disrupt the outcome of your assay.
a.
Added a non-competitive inhibitor to Enzyme A
b. Added an allosteric modulator to Enzyme A
c.
Switched Enzyme A with an enzyme that has a lower Km
d. Switched Enzyme A with an enzyme that has a higher Km
e.
Both b and d are possible explanations
f.
Both a and c are possible explanations
4. Compare and contrast the function of a simple epithelium and a single cell
membrane in the body and the cell. How are the similarities and differences in
the function of the membrane and the epithelium reflected by their respective
structures?
5. Why do some signaling pathways use ‘multiple-enzyme sequences’ to
transduce the binding of a ligand to a receptor.