Download Week_4_Practice questions

Biol 200 Practice Questions for Week 4 & 5 Crowe F2013 1. Fats are good at storing chemical energy. Based on what you know about chemical
bonds, explain why this is the case. (2 sentences, maximum)
2. The relative orientation of polar and nonpolar amino acid side chains of integral
membrane proteins is “inside-out” compared to the amino acid side chain orientation
for a globular water-soluble protein in a cell’s cytoplasm. Explain why. (2 sentences,
maximum)
3. You discover a bacterium, C. jejuni, which can only use fucose (C6H12O5) as an energy
source. You isolate an enzyme from C. jejuni which phosphorylate fucose resulting in a
molecule called fucose-1-phosphate also called fucose 1-P. Fucose must be converted into
fucose 1-P in order to be used as an energy source.
You decide to name your enzyme using the traditional naming system for enzymes (based on
their activity).
a) You name the enzyme: ____________________________________ (2 words, maximum)
b) You find that addition of a regulatory molecule to your enzymatic reaction along with fucose
lowers the level of fucose 1-P produced. Adding increasing amounts of fucose does not change
the effect of the regulatory molecule. What type of regulation is occurring? Be as specific as
possible with your answer.
___________________________________________________________ (3 words, maximum)
Biol 200 Practice Questions for Week 4 & 5 Crowe F2013 c) You decide to see if there are any other substrates for your enzyme. When you mix the
enzyme with fucolose, a sugar with the same chemical formula as fucose, (C6H12O5), no fucose
1-P is produced. Assuming that nothing was wrong with your experiment, what is a likely
molecular explanation for this observation?
(1 sentence, maximum).
Fucose 1-P
You want to learn more about the activity of your
enzyme, so you perform an experiment measuring
enzyme activity at different temperatures in the
presence of fucose. You obtain the graph in Fig.
1.
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Temperature (°C)
d) What is a molecular explanation for the low
level of fucose 1-P observed at 20°C? (1 sentence,
maximum)
Fig 1.
e) What is a molecular explanation for the low level of fucose 1-P observed at 80°C? (1 sentence,
maximum).