Answer:
5877.8625954198 kilogram/cubic meter
Answer: W = 6.4x10⁻²¹J
Explanation: <u>Work</u> is the energy transferred to or from an object due to the application of a force along a displacement.
The ion Na is gaining energy to move from a lower potential to a higher one.
For this to happen, the work done is calculated as
in which
W is work in Joules (J)
q is charge in Coulomb (C)
is potential difference in Volts (V)
The ion Na has one positive charge. In coulombs, the charge is
q = 1.6x10⁻¹⁹C
The potential difference in Volts is
= 40x10⁻³ or 4x10⁻²V
Calculating
W = 1.6x10⁻¹⁹. 4x10⁻²
W = 6.4 x 10⁻²¹ J
The work done to move an ion of sodium from the exterior to the interior is 6.4 x 10⁻²¹ J.
Answer:
A) A decrease in Na+ permeability, and an increase in K+ permeability.
Explanation:
When the potential action reaches a peak of about +40 mv Na+ channels are open and a high number of Na+ ions are entering the inside of the cell. Shortly after this happens the K+ channels will start to open their gates increasing the cell K+ permeability while the Na+ channels will start to close their gates, so the Na+ permeability will decrease. This happens in order to valance the positive charge on the inside of the cell. Normally the inside has a negative charge while the outside has a positive one, as the inside is more positive due to the increase in Na+ permeability at the beginning of the potential action, K+ cations (which are in abundance in the cell) will have to go out through the K+ channels so as to restore the charge valance, that means that there is an increase in K+ permeability.
