BIOL 2160 Chapter : Chapter 1

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azuremammoth471

15 Mar 2019

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2 main ions that factor in the most- sodium and potassium. Potassium on the inside is larger than sodium: more potassium. Sodium on the outside is larger than potassium: more sodium. Will always be more potassium inside than outside the cell. Will always be more sodium outside than inside the cell. Go in- things move in the direction of lower concentration. These ions both have a positive charge- the cell also has a charge that changes. Inside the cell is negative: the ions are positive so it is attracted inside. Inside the cell is positive: so are the ions so it is repelled out. Equilibrium potential: the membrane potential at which the chemical and electrical gradients perfectly counter balance each other. If membrane potential, is more positive than +55, then sodium goes out. If you want potassium to go in against membrane potential, you have to make the cell very negative.

Related Questions

(1) What would be thelikely outcome if an increase in both intracellular sodium ionlevels and extracellular potassium ion levels were tooccur?

A: The Na+-K+ pump would accelerate because it needs to restorethe membrane's resting concentration gradient.

B: The Na+-K+ pump would slow down because it needs to restorethe membrane's concentration gradient.

C: Sodium and Potassium ions would be pumped out of thecell.

D: Sodium and Potassium ions would increase their movement inboth directions across the cell membrane.

(2) Due to the unequal transport of sodium and potassiumions by the Na-K pump, a membrane potential isgenerated.

True or False

(3) If a pump moves 3 positive ions out and 2 positiveions in against their concentration gradients, the membranepotential in the cell will become more positive.

True or False

skyrabbit531

I need help answering this question:

Observation: A strange deep sea creature has been discovered. You are recording from a neuron in itâs brain with an electrode. Upon electrical stimulation, you observe change in voltage that resembles an action potential: the voltage rises, shoots up when it crosses a threshold, and then rapidly falls back to resting potential. Looking at the ions inside and outside the cell, you find that there is a high concentration of positively charged Lithium ions outside the cell and low concentration inside the cell. There is also a high concentration of potassium ions inside and low outside. Finally, there is an equal amount of Chloride ions on both sides. Strangely enough, there arenât any Sodium ions around.

Based on these observations, you ask âIf there is no sodium, what ion is mediating the âaction potentialâ?â

In 100 words or less: 1. Formulate a hypothesis as to what ion might be mediating the action potential.2. Design an experiment to test your hypothesis. 3. State what outcome would confirm your hypothesis.

During active transport in the neuron, the outside of the cell is _________________ and the inside is _______________.

positive, negative

more positive, less positive

more negative, less negative

negative, positive

In active transport, _____________ provides the energy to move molecules against their concentration gradient.

nucleus

potassium

sodium

adenosine triphosphate

________________ proteins can change shape when moving substances across the membrane.

Proteins that can be open or closed, based on different conditions, are called ___________.