SMALLFIDGET
Forum Junior
Topics: 9
Posts: 72
|
1.A new drug was found to decrease Hepatitis B virus. The drug is an analogue of one of the nucleic acid bases of DNA and probably works by being incorporated into the virus and disrupting viral genes during viral DNA replication. However, patients in a clinical trial of the drug began to experience drastic overproduction of lactic acid and liver failure leading to death. The most likely explanation for the problem:
A. Incorporation of the drug into mitochondrial DNA disrupts the ability of mitochondria to make ATP.
B. The virus with mutations must overproduce lactic acid.
2.In the first step of glycolysis, the enzyme hexokinase uses ATP to transfer a phosphate to glucose to form glucose-6-phosphate. The product continues to be oxidized forming pyryvate in glycolysis and is a precursor to acetyl-CoA for the citric acid cycle. Suppose that a cell has only glucose available for energy and that the activity of hexokinase is suddenly stopped in this cell. Which of the following conditions will occur?
A. The cell will continue to produce energy from mitochondrial electron transport.
B. The cell will continue to produce ATP using the citric acid cycle.
C. The cell will ultimately be unable to produce ATP.
D. The cell will be forced to switch to fermentation to produce ATP.
E. The use of oxygen by the cell will increase
3.During a heart attack, blood flowing to the heart muscle is interrupted by blockage of a coronary artery. How would you expect the metabolism in the heart to change?
A. oxidative phosphorylation would slow down in the mitochondria
B. the rate of production of lactic acid would be stimulated
C. the use of glucose by the muscle tissue would increase
D. the production of water by mitochondria would be inhibited
E. all are expected metabolic changes
___________________
VR.
|
| MLF
Forum Elite
Topics: 36
Posts: 386
|
A???
___________________
"Support bacteria, its the only culture some people got."
|
| bluedusk
Forum Elite
Topics: 35
Posts: 217
|
1. I like the implication that by debilitating the e transport chain you gain NADH and shunt pyruvate to lactose. But I don't see the need for DNA synthesis in hepatocytes, which are stable cells. Is there a choice that indicates affecting e transport on another level (perhaps transcription?)
2. B - I'm assuming the cell can't perform gluconeogenesis to get around the defect, but it should be able to utilize acetyl-CoA from fatty acid ox to continue the citric acid cycle....
|
| bluedusk
Forum Elite
Topics: 35
Posts: 217
|
Didn't see 3 - E.
|
| Malaysian
Forum Guru
Topics: 28
Posts: 778
|
1.A
2.C
3.E
|
|
| |
| | | | | |
