What happens to the resting potential of a neuron as extracellular K+ concentration is increased?
Q. In this case, assume that there will be no change to intracellular K+ concentration. I had thought that the potential becomes more negative, especially considering no change in intracell. K+ concentration; but apparently that's wrong. Also, what would happen to an action potential under these conditions.
Asked by Dr. J - Sat Mar 21 10:07:06 2009 - - 1 Answers - 0 Comments

A. Assuming that the concentrations of Na+, like the intracellular concentration of K+, does not significantly change, an increase in extracellular K+ concentration results in a decrease in resting membrane potential (that is, it becomes less negative). This, in turn, produces a decrease in the force of contraction, and the rate at which action potential travels across the muscle. In extreme cases ( hyperkalemia ), the rate may be slowed so far that "ectopic" pacemakers can emerge in the ventricles. Therefore, one of the major effects of this condition is an increase in muscle cell excitability, because their resting potential is closer to the threshold for generating action potentials, and the equilibrium potential of K+ is positively… [cont.]
Answered by LAlawMedMBA - Wed Mar 25 06:43:37 2009

is vitamin k good to apply around the eyes to try and get rid of bags?
Q. i have bags under my eyes, even when i get plenty of sleep. they aren't puffy or dark tho... will breaking open a vitamin k capsule and applying it around my eyes help? or is another vitamin better?
Asked by Tessa - Mon Feb 25 23:33:55 2008 - - 2 Answers - 0 Comments

A. 1.Swallow a capsule of cod liver oil everyday. It strengthens eyes. Take a teaspoon of tomato juice, a few drops of lemon juice, a pinch of turmeric powder and a little flour, enough to make a paste. 2. Apply this paste to the under-eye area, and wash off after fifteen minutes. 3.Apply Vitamin E to the area under your eye. You could open up a Vitamin E capsule, and apply a little oil. Swallow the rest of the oil. 4. Lie down, close your eyes and apply cucumber or potato slices to your lids. Leave on for ten minutes and remove. Wash the area with cold water. This soothes tired eyes instantly, and helps boost blood circulation in the under-eye area.
Answered by icB2 - Mon Feb 25 23:54:12 2008

What are the units of k in the rate law and how do they relate to the reaction orders?
Q. How do you know stuff like: if the reaction is first order in A and second order in B, and time is measured in minutes, what are the unts for k? This is just for the general equation aA +bB --> cC +dD
Asked by Kiko - Sat Feb 3 18:47:34 2007 - - 1 Answers - 0 Comments

A. The rate law is: v = k*[A]*[B]^2 Solve for k: k = v/([A]*[B]^2) and v is in mol/L*min, [A] in mol/L and [B] in mol/L, so: k units are: L^2/(mol^2*min)
Answered by Dimos F - Sat Feb 3 19:03:55 2007