Different types of equilibrium and states

[roxasblade]

Hi guys,
I'm working on a TBR Biology question and was confused on:

39: The constancy of the resting membrane potential is an example of:
A. an equilibrium state
B. a dynamic state
C. a steady state
D. a static state

Could someone explain the difference between a dynamic state and a steady state? Thanks

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[aldol16]

I'm not sure I've ever heard those terms ever formally defined in chemistry. A steady-state is generally used in kinetics, however, where we apply the so-called "steady-state approximation," meaning that the concentration of an intermediate in a reaction builds up to some steady state, or constant concentration, and stays that way throughout the course of the reaction. This doesn't mean that the flux through the pathway is zero though - it just means that the rate of formation of the intermediate equals the rate of disappearance.

 

[basophilic]

I would guess the answer to be dynamic state because the RMP is maintained through opposite activities of K+ leak channels and Na/K ATPase

 

[roxasblade]

I would guess the answer to be dynamic state because the RMP is maintained through opposite activities of K+ leak channels and Na/K ATPase

I thought that also, but TBR says the answer is steady-state because it requires energy (in terms of ATP for the Na+/K+ pump) to maintain the concentration of the ions.

This is how TBR defines it:
Equilibrium: when equilibrium can be reached without the use of energy input
Steady state system: when state is constant, but energy is used to maintain that state.

This is from my undergraduate physiology book: Vander's Human Physiology:
1) Dynamic constancy:"homeostasis is a state of dynamic constancy. In such a state, a given variable like blood glucose may vary in the short term but is stable and pre- dictable when averaged over the long term"

2) Steady state: "defined as a system in which a particular variable—temperature, in this case—is not changing but in which energy—in this case, heat—must be added continuously to maintain a constant condition"

3) Equilibrium: "in which a particular variable is not changing but no input of energy is required to maintain the constancy."

I feel that the RMP would be considered both dynamic and steady state then, wouldn't it?