Download This is Most of an Old Exam

This is Most of an Old Exam. Please do NOT study just from this exam. Do the
questions at the back of chapters too!!!!!
Name
General Physiology
Write the letter of the best answer in the space provided at the left. There is only one
correct answer for each question (5 points each).
_____ 1.Which of the following statements regarding metabolic processes is FALSE?
A.
Cellular oxidation of food fuels is the immediate source of electrons for oxidative
phosphorylation.
B. In oxidative phosphorylation, both the electron transport proteins and the ATP
synthase molecules are in the same membrane.
C. NAD+ and FAD+ are hydrogen carrier molecules. NAD+ can carry one hydrogen and
electron, FAD+ can carry two.
D. Hexokinase, the enzyme that catalyzes the first reaction in glycolysis, is highly
regulated via allosteric mechanisms.
_____ 2.Synthesis of glucose from non-carbohydrate precursors is called gluconeogenesis.
Gluconeogenesis
A.
is activated when blood glucose is low and an organisms glucose supplies are
limited.
B.
uses glycogen as a source of new glucose molecules to maintain blood glucose.
C.
can make new glucose molecules from the direct reversal of the glycolytic
pathway.
D.
is only activated when adipose depots of triglycerides are low.
Write brief, but complete to questions 1-3. Then choose two questions from question 4-7,
and write your answers (12 points each).
1. You are examining the activity of enzymes in hummingbird flight muscles. You
perform specific spectrophotometric analyses for lactate dehydrogenase (LDH), citrate
synthase (CS) and hydroxyacyldehydrogenase (HAD). The raw data from your analyses
is shown below. Assume that in each assay you used an equivalent amount of muscle
protein. Do the activities of these enzymes meet your expectations for hummingbird flight
muscle? Why or why not? Explain your answer in terms of metabolic pathways and their
regulation..
Time (min)
0
0.5
LDH
2.011
1.875
Absorbance
CS
1.887
1.743
HAD
1.898
1.884
1.0
1.5
2.0
2.5
3.0
1.486
1.186
0.975
0.795
0.555
1.623
1.515
1.235
1.003
0.798
1.796
1.794
1.795
1.796
1.797
3. We are indirectly examining the metabolic pathways and fuels used by a
marathon runner. We do this by measuring changes in O2 breathed in vs. breathed
out, and the changes in CO2 breathed out. The following figure describes the results
of our measurements over the course of the marathon. What kind of metabolism is
probably taking place during the first 60 min of the marathon? What is the main fuel
being used? Why can you say this? What kind of metabolism is probably taking
place following 60 min of running? What fuel(s) is (are) being used? Why can you
say this?
CO2
exhaled
O2
consumed
0.5
1.0
1.5
time (hours)
Answer 2 of the following four questions. Use no more than half a page for each
answer and be sure to indicate which questions are being answered.
4. There are at least two gradients important in the process of oxidative phosphorylation.
What are two of the gradients and why are they important to the production of ATP?
5. How many molecules of O2 will be consumed during the oxidation of 1 molecule of
palmitate (a 16-carbon fatty acid)? Explain how you get your answer.
6. What are the two main functions of he proteins of the electron transport chain? How
are these two functions related to one another?
7. Given what you know about how enzymes are regulated, explain which enzymes you
think might be highly regulated in glycolysis, the Krebs cycle, and the cycle for
oxidation of fatty acids. Explain your choices and speculate what might be a regulator
for each enzyme you choose.