Before an action potential begins, the fluid outside an axon's membrane has ions; the fluid inside has ions.

4. rat liver is able to metabolize glucose by both the glycolytic and the pentose phosphate pathway. which of the following are properties of both the glycolytic and pentose phosphate pathway? a. nad+ is involved b. co2 is liberated c. phosphate esters are intermediates d. glyceraldehyde 3-phosphate is an intermediate e. fructose 6-phosphate is an intermediate4. rat liver is able to metabolize glucose by both the glycolytic and the pentose phosphate pathway. which of the following are properties of both the glycolytic and pentose phosphate pathway? a. nad+ is involved b. co2 is liberated c. phosphate esters are intermediates d. glyceraldehyde 3-phosphate is an intermediate e. fructose 6-phosphate is an intermediate

The kidney filters potentially toxic substances in the blood, and thus “clears” the blood of those substances. this clearance function is dependent upon and proportional to the diffusion gradient of the substance across filtering capillaries, i.e. if the concentration of the substance is doubled, twice as much will be cleared from each ml of blood that is filtered. suppose that the body produces a constant amount of a substance x per unit of time. the kidneys eliminate substance x at a rate directly proportional to the concentration of the substance and the volume of blood cleared each minute (c): elimination = c × [x], where [x] is the steady-state concentration of substance x. imagine an individual with an initial concentration of x equal to [x]0 who develops kidney disease. her baseline clearance c0 drops to one half of the original (½c0). what is the new steady state concentration of x? (for simplicity, assume that substance x is 100% filtered by the kidney).

There are only about 250,000 known fossil species. true or false