Exam 5: Aerobic Respiration and the Mitochondrion

Rat liver mitochondria are isolated and placed in an assay medium.What happens to the pH of the medium when the medium is kept anaerobic? What happens when O₂-saturated saline is added to the mixture?

You prepare red blood cell ghosts with a very high internal potassium ion concentration and a very high external sodium ion concentration,higher than normally exists in the body.The red blood cell ghost also contains ADP and inorganic phosphate ions in the interior and the Na⁺-K⁺ pump in the membrane.What happens?

When fusion of mitochondria becomes more frequent than fission,the mitochondria tend to become __________.

How can biologists be sure that the appearance of photosynthetic organisms preceded that of aerobic organisms in the Earth's evolutionary history?

Electrochemical gradients have both a(n)_________ and a(n)__________ component.

In the experiment that demonstrated that rotational catalysis occurs,a fluorescently labeled actin filament attached to the ATP synthase enzyme's  subunit was seen to rotate when ATP was added to the enzyme,which was fixed to a cover slip.With each step in the rotational catalysis,how much could the actin filament be seen to rotate?

Which organelle below is not found in both plants and animals?

To what is the 2-carbon fragment of acetyl CoA added to make citric acid at the start of the Krebs cycle?

The balance between fusion and fission is likely a major determinant of __________.

A doctor in a hospital emergency room sees an obese patient who has come into the emergency room.He has been losing weight rapidly but complains that he has lost energy and is tired most of the time.During his interview with the patient,the doctor thinks he has discovered what is causing the man's condition.What do you think he has found?

Which muscles would contain more fast-twitch fibers,arm muscles or the postural muscles of the back?

You are a world-wide expert in mitochondria.If an investigator tells you that he wishes to study mitochondrial uncoupling proteins,what kind of organism would you suggest he use as a source of the protein? What is the function of brown adipose tissue? Humans lose brown fat deposits as they age.How does that happen and how do humans maintain body temperature when the brown fat is gone? Uncoupling protein (UCP)isoforms are found in cells of the nervous system.While their roles are debated,what is the most prominent hypothesis that may explain their function?

What is unusual about the way that H⁺ ions are transported across the inner mitochondrial membrane as compared to the movement of other ions like Na⁺ and Cl^- ions?

The direct formation of ATP by the transfer of a phosphate group from a donor molecule to ADP is called ________.

You are studying the enzyme kinetics of enzymes in the TCA cycle.You add a molecule to the mixture that appears to act as a competitive inhibitor of one of the enzymes.At first,you cannot tell which enzyme is inhibited,but you can tell that it is bound to the inner mitochondrial membrane.Can you guess which TCA enzyme you have inhibited and how do you know?

In the early 1980s,a number of young drug addicts showed up in hospitals with the sudden onset of severe muscular tremors that are characteristic of advanced Parkinson's disease (PD)in elderly adults.What caused these PD-like symptoms in such young people? How were the cells of the substantia nigra in PD patients similar to those in the substantia nigra of MPTP patients? What are some possible environmental causes of PD?

What is the name of the process by which the electron transport chain generates the electrochemical gradient that drives ATP production in the mitochondrion?

You have isolated some muscle cells in a tissue culture system.You are able to get them to contract in culture.If you add an inhibitor of the electron transport system to these cells,they do not contract quite as much,but they still contract noticeably.What kind of muscle fiber type are you employing?

How do mitochondria generate and store the energy used to produce most of the ATP made during aerobic respiration?

What is the terminal electron acceptor of the electron transport chain?