IB Biology Course Companion Book Pg. 244
1. a. Outline the relationship between sodium ion/potassium ion pump function and ouabain concentration. [2]
As the concentration of oubain increases, the Na+/K+ synthase pump activity decreases, there is a negative correlation. This is shown by the ouabain concentration is 0M there is 100% activity of ATPase activity and this then falls o 0% when the ouabain concentration is 0.016M.
However, it's not exactly inversely proportional as the line on the graph isn't straight.
b. Predict the ouabain concentration at which sodium ions/potassium ion function would be 25% [1]
About 0.004M
c. Explain why ouabain might be able to kill a large mammal [2]
By stopping the Na+/K+ pump activity, neurons are unable to pass an action potential across the body. At the synapse the action potential won't be able to pass the synapse cleft due to no diffusion of movement of Na+ or K+. The animal will be rendered paralyzed.
If the pump isn't available, then when sodium diffuses into the neurone it stays in, when potassium diffuses out it stays out. This means that the concentration gradient necessary to return back to resting potential isn't available.
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ReplyDeleteGood work, shame it's the wrong set of questions! DBQ on p244...)
ReplyDeleteSorry Mr. Friend! I did the questions on the wrong page.
ReplyDeleteI corrected it and put the right set of questions up :)