Workshop #8

A. Oxygen is a waste product of non-cyclic photophosphorylation because of the breakdown of H2O during the process. H2O breaks down into O2 + H+ + e- and the e- is needed to power the proton pump and carry out the rest of the cycle.

B. The lifespan of red blood cells from athletes is less than that from a sedentary human because athletes breathe more toxic O2 which breaks down biomolecules.

C. The master must have made the soy sauce in an O2 free environment, as it is rich in lactic acid and ethanol. My soy sauce tasted "vinegary" because I made it in an environment where O2 is present and acetic acid was produced.

D. With freely isolated mitochondria, pyruvate, ADP and Pi in solution, ATP is produced. This is because the pyruvate is used to produce acetic acid for the citric acid cycle to produce NADH which powers ETS which produces ATP.

E. An experiment similar to D is conducted but without the presence of pyruvate and ATP is still detected. Why? There are still proton gradients that will still allow the process to continue for some time, but will eventually stop making ATP when the gradients run out of energy.

F. If the proton gradient is unrestricted, the proton concentration will go to Keq and there will no longer be a gradient. If there is no gradient then no ATP will be produced. Mitrochondria in these cells contain this extra complex as another way for electrical energy to generate heat and insulate an animal.

G. The molecules that were radioactive in the student's urine is the H2O. The radioactive O2 was used in a coupled reaction to form H2O in ETS.

H. NEED: ATP/sec + glucose/sec
100,000 PL/1,000 sec x 5 ATP/1 PL = 500 ATP/sec needed to support the generation of a new membrane.
1 glucose transporter/cell. So,
500 ATP/sec x 1 glucose/2 ATP = 250 glucose/sec needed to support that metabolic rate.