Neuroscience Chapter 11 - Membrane Potential
48 Questions
0 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to Lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the membrane potential primarily a result of?

  • The physical structure of the plasma membrane
  • The difference in concentration and charge of ions across the plasma membrane (correct)
  • The movement of ions in and out of the cell
  • Equal distribution of ions inside and outside the cell

How does the presence of an electrical gradient influence ion movement?

  • Ions are equally likely to move in any direction
  • Ions will not move until an external force is applied
  • Positively charged ions are attracted to negatively charged areas (correct)
  • Ions will move away from regions with similar charge

What is true about the charge inside and outside of most cells?

  • The inside is generally more positively charged than the outside
  • The outside is usually more negatively charged than the inside
  • The outside is typically more positively charged than the inside (correct)
  • The inside and outside have the same charge

What measurement technique could be used to assess the membrane potential?

<p>An oscilloscope using both a reference electrode outside and a recording microelectrode at the cell surface (C)</p> Signup and view all the answers

What is created when there are higher amounts of particular ions on one side of the plasma membrane?

<p>Concentration gradient (C)</p> Signup and view all the answers

Which statement best describes the characteristics of neurons in relation to membrane potential?

<p>Neurons utilize their charge difference more effectively than most other cells (B)</p> Signup and view all the answers

What happens if the measurement electrodes are both placed outside the cell?

<p>The voltage reading would be approximately zero (D)</p> Signup and view all the answers

Why do ions move towards areas of opposite charge?

<p>Opposite charges create an attractive force (A)</p> Signup and view all the answers

What primarily establishes the resting membrane potential in a neuron?

<p>Higher concentration of potassium inside the cell compared to sodium (A)</p> Signup and view all the answers

What role do potassium leak channels play in resting membrane potential?

<p>They increase the permeability of the membrane primarily to potassium (A)</p> Signup and view all the answers

At resting membrane potential, what is the approximate electrical charge difference across the membrane in neurons?

<p>Negative 70 millivolts (B)</p> Signup and view all the answers

How do negatively charged proteins contribute to resting membrane potential?

<p>They contribute to the small negative charge just inside the membrane. (D)</p> Signup and view all the answers

What happens when a potassium channel opens in terms of ion movement?

<p>Potassium ions will primarily move in accordance with their concentration gradient. (D)</p> Signup and view all the answers

What is the primary ion that influences the resting membrane potential due to its higher permeability?

<p>Potassium (C)</p> Signup and view all the answers

What establishes the balance between the influx and efflux of potassium ions in a resting neuron?

<p>The opposing electrical gradient generated by negatively charged proteins (C)</p> Signup and view all the answers

Why is the concentration of sodium higher outside the neuron than inside?

<p>The sodium-potassium pump actively transports sodium out. (B)</p> Signup and view all the answers

What is the primary focus of the lecture on resting membrane potential?

<p>The creation of electrical signals (D)</p> Signup and view all the answers

Which component of the cell membrane is primarily responsible for controlling the movement of substances in and out of the cell?

<p>Transport proteins (A)</p> Signup and view all the answers

What do the colored structures in the image represent?

<p>Transport proteins (A)</p> Signup and view all the answers

Which of the following best describes the resting membrane potential?

<p>The difference in electric charge on either side of the membrane when the neuron is not actively transmitting signals (D)</p> Signup and view all the answers

What effect does the phospholipid bi-layer have on the movement of substances?

<p>It restricts movement of certain ions or molecules (C)</p> Signup and view all the answers

Why is controlling the movement of ions across the membrane important for neurons?

<p>To establish and maintain resting membrane potential necessary for electrical signaling (B)</p> Signup and view all the answers

What is depicted in the blown-up version of the axon cell membrane?

<p>Phospholipid bi-layer and transport proteins (D)</p> Signup and view all the answers

Where can key features of cell membranes be reviewed?

<p>Chapter 3 of the textbook (A)</p> Signup and view all the answers

What happens to the net charge inside the cell as potassium ions leave the cell?

<p>It becomes more negative because negatively charged proteins remain. (C)</p> Signup and view all the answers

What primarily establishes the resting membrane potential?

<p>The balance between potassium ions moving in and out of the cell. (D)</p> Signup and view all the answers

How does the movement of potassium ions illustrate the concept of an electrical gradient?

<p>Positive potassium ions are attracted to the negative charge inside. (A)</p> Signup and view all the answers

What role do negatively charged proteins play when potassium leaves the cell?

<p>They create a negative charge inside that attracts potassium back. (B)</p> Signup and view all the answers

What will occur if more potassium ions begin to leave the cell?

<p>The interior of the cell will continue to become more negative. (A)</p> Signup and view all the answers

What prompts potassium ions to move back into the cell despite a concentration gradient favoring their exit?

<p>The attraction to the negative charge inside the membrane. (D)</p> Signup and view all the answers

What is the initial effect on the charge outside the cell when potassium ions exit?

<p>The outside charge becomes net positively charged. (A)</p> Signup and view all the answers

What creates a concentration gradient for potassium ions inside the cell?

<p>The activity of the sodium-potassium pump. (A)</p> Signup and view all the answers

What does a negative resting membrane potential indicate about the cell's interior compared to its exterior?

<p>The inside of the cell is more negatively charged than the outside. (A)</p> Signup and view all the answers

How does the concept of potential difference across the membrane relate to values like positive 70 millivolts and negative 70 millivolts?

<p>Both values represent the same potential difference across the membrane. (A)</p> Signup and view all the answers

What happens to membrane potential if potassium ion channels are increased?

<p>The membrane potential increases due to enhanced movement of potassium out of the cell. (D)</p> Signup and view all the answers

What is the relationship between resting membrane potential and potassium's ability to diffuse out of the cell?

<p>Resting membrane potential is proportional to the potential for potassium to diffuse, not to the flow rate. (A)</p> Signup and view all the answers

What misunderstanding do students often have regarding decreasing membrane potential?

<p>They believe decreasing membrane potential means becoming more negative. (A), They think it requires moving farther from zero into the negatives. (B)</p> Signup and view all the answers

What would a resting membrane potential of negative 90 millivolts signify for muscle tissues?

<p>Muscle tissues have a resting potential that is more negative than most cells. (A)</p> Signup and view all the answers

What does the term 'equilibrium' refer to in the context of potassium movement at resting membrane potential?

<p>A condition where the electrical and chemical gradients for potassium balance. (C)</p> Signup and view all the answers

What is the implication of a cell having a resting membrane potential significantly different from zero?

<p>It necessitates a continuous input of energy to maintain that potential. (B)</p> Signup and view all the answers

What is the primary function of ATP in the sodium-potassium pump?

<p>It provides energy to maintain the ion concentration gradients. (C)</p> Signup and view all the answers

What happens to the binding sites of the sodium-potassium pump after ATP is broken down?

<p>They face towards the outside of the cell, allowing sodium to leave. (D)</p> Signup and view all the answers

What occurs immediately after sodium ions leave the sodium-potassium pump?

<p>Potassium ions bind to the pump. (D)</p> Signup and view all the answers

How does the sodium-potassium pump counteract the leakage channels present in the cell membrane?

<p>By using ATP to transport ions against their concentration gradient. (B)</p> Signup and view all the answers

What is the result when the inorganic phosphate detaches from the sodium-potassium pump?

<p>It allows the pump to return to its original shape. (C)</p> Signup and view all the answers

Which statement accurately describes the concentration of sodium and potassium ions in a resting cell?

<p>High potassium concentration inside the cell and low sodium concentration outside. (B)</p> Signup and view all the answers

What is the mechanism by which sodium ions move during the operation of the sodium-potassium pump?

<p>They are actively transported out of the cell against their concentration gradient. (C)</p> Signup and view all the answers

Which of the following best describes the role of leak channels in a resting cell?

<p>They allow potassium to leave and sodium to enter the cell. (B)</p> Signup and view all the answers

Flashcards

Concentration Gradient

The movement of ions across a membrane from a region of high concentration to a region of low concentration.

Electrical Gradient

The movement of ions across a membrane from a region of high electrical charge to a region of low electrical charge.

Resting Membrane Potential

The potential difference across a cell membrane when the cell is not transmitting a signal.

Sodium-Potassium Pump

An active transport protein that pumps sodium ions out of the cell and potassium ions into the cell, creating concentration gradients.

Signup and view all the flashcards

Membrane Potential

The difference in electrical charge across a cell membrane due to the movement of ions.

Signup and view all the flashcards

Potassium Efflux

The movement of potassium ions out of the cell due to a concentration gradient.

Signup and view all the flashcards

Potassium Influx

The movement of potassium ions into the cell due to an electrical gradient.

Signup and view all the flashcards

Equilibrium

The point at which the movement of potassium ions out of the cell is equal to the movement of potassium ions into the cell.

Signup and view all the flashcards

Permeability

The cell membrane is much more permeable to potassium ions than sodium ions.

Signup and view all the flashcards

Negatively Charged Proteins

Large negatively charged molecules trapped inside the cell, creating a negative charge near the membrane.

Signup and view all the flashcards

Potassium Movement

Potassium ions have a tendency to move out of the cell due to their concentration gradient.

Signup and view all the flashcards

Resting Potential Maintenance

The resting membrane potential is maintained by the balance of potassium ion movement driven by both concentration and electrical gradients.

Signup and view all the flashcards

Ion Channel

A specialized membrane protein that allows for the controlled movement of specific ions across the cell membrane.

Signup and view all the flashcards

Action Potential

The process by which neurons transmit signals along their axons. This involves a rapid shift in membrane potential, creating an electrical impulse.

Signup and view all the flashcards

Synaptic Transmission

The ability of neurons to communicate with each other by transmitting signals across a small gap called the synapse.

Signup and view all the flashcards

Synapse

The specialized junction between two neurons where chemical signals are transmitted from one neuron to the next.

Signup and view all the flashcards

Active transport

The process of actively transporting molecules across a cell membrane against their concentration gradient, requiring energy.

Signup and view all the flashcards

ATP

A molecule that provides energy for cellular processes by transferring a phosphate group to another molecule.

Signup and view all the flashcards

ATP hydrolysis

The process of breaking down ATP into ADP and inorganic phosphate, releasing energy.

Signup and view all the flashcards

Leak Channels

Channels in the cell membrane that allow passive diffusion of ions, leading to a gradual equalization of ion concentrations.

Signup and view all the flashcards

Passive diffusion

The movement of molecules across a membrane from an area of high concentration to an area of low concentration, requiring no energy.

Signup and view all the flashcards

What is Resting Membrane Potential?

The electrical difference between the inside and outside of a neuron at rest. It's like a battery that's charged and ready to fire.

Signup and view all the flashcards

Neuron

A specialized cell that transmits information through electrical and chemical signaling.

Signup and view all the flashcards

Cell Membrane

The thin outer layer of a cell, made up of a phospholipid bilayer. It acts as a barrier and controls what can pass in and out of the cell.

Signup and view all the flashcards

Phospholipid Bilayer

A barrier formed by two layers of phospholipids. It's selectively permeable, meaning only some substances can pass through.

Signup and view all the flashcards

Transport Proteins

Special proteins embedded in the cell membrane that help transport molecules across the membrane. They act like helpers for molecules that can't pass through the phospholipid bilayer.

Signup and view all the flashcards

Cytosol

The internal fluid of a cell, containing dissolved molecules and ions. It's where many cell processes take place.

Signup and view all the flashcards

Extracellular Space

The space outside of a cell, containing fluids and molecules. It's where communication between cells takes place.

Signup and view all the flashcards

Selectively Permeable

The ability of a cell membrane to let certain substances pass through while blocking others. This selective barrier helps maintain the cell's internal environment.

Signup and view all the flashcards

Ion Flow

The movement of ions across a membrane, driven by differences in concentration and electrical charge.

Signup and view all the flashcards

Increasing Membrane Potential

An increase in the difference in electrical charge between the inside and outside of a cell membrane. The value moves further away from 0 in a more negative direction (e.g., from -70 mV to -90 mV).

Signup and view all the flashcards

Decreasing Membrane Potential

A decrease in the difference in electrical charge between the inside and outside of a cell membrane. The value moves closer to 0 (e.g., from -70 mV to -50 mV).

Signup and view all the flashcards

Potential for Potassium Diffusion

A hypothetical value that represents the maximum possible movement of potassium ions out of the cell. It's proportional to the resting membrane potential but not the actual rate of flow.

Signup and view all the flashcards

Actual Rate of Potassium Flow

The actual movement of potassium ions across the membrane. At resting membrane potential, the rate of flow is very low because the system is in equilibrium.

Signup and view all the flashcards

Muscle Cell

A specialized type of cell found in tissues like muscle that typically has a more negative resting membrane potential (around -90 millivolts) than a typical neuron.

Signup and view all the flashcards

Study Notes

Introduction

  • Neurons create electrical signals, a process studied in membrane potential
  • Membrane potential defines the electrical charge difference across the neuron membrane
  • Initial study of neuronal structure followed by membrane potential creation

Slide 1

  • Lecture material in chapter 11 of the textbook, focusing on electrical signals and resting membrane potential
  • Key cell membrane features crucial for understanding
  • Membranes composed of phospholipid bilayers, with embedded transport proteins
  • Proteins control what enters/leaves cell, crucial for membrane potential
  • Review of chapter 3 for further details on cell membranes recommended

Slide 2

  • Neurons are electrically excitable; they transmit signals
  • Polarized membranes have different charges on either side
  • Ions with different charges (cations, anions) create a charge difference
  • The difference in ion concentration creates both concentration and electrical gradients across the membrane

Slide 3

  • Similar charges repel, opposite charges attract
  • Polarized membrane created by separating charges across the membrane
  • Separated charges create potential, a voltage, or electrical force

Slide 4

  • Neurons and other cells have charge differences across the membrane
  • Outside the membrane is positive, inside is negative typically
  • A microelectrode measures the difference in charge across the membrane: voltage or membrane potential
  • Voltage difference of negative 70 millivolts (mV) is the resting potential of a neuron

Slide 5

  • Describes resting membrane potential as the difference in voltage when not actively sending a signal
  • Explains the relationship between ion concentrations on either side of the cell membrane
  • Shows a table of ion concentrations (e.g., sodium, potassium, calcium, chloride, and proteins). Explains higher/lower concentrations

Slide 6

  • Explains the sodium-potassium pump, an active transport mechanism
  • Sodium-potassium pump actively moves sodium ions out and potassium ions in, maintaining concentration gradients
  • This process requires energy, using ATP, and plays a fundamental role in maintaining resting membrane potential

Slide 7

  • Describes leak channels, channels that are always open, allowing ions to diffuse down their concentration gradients.
  • Sodium and potassium leak channels are described
  • Concentration gradients are crucial to maintain the cell's resting state.

Slide 8

  • Explains how ion channels affect membrane permeability and maintain ion concentrations
  • Two main types of ion channels are explained: leak channels (always open) and gated ion channels (open/close based on signals).
  • Gated channels are crucial for changing the membrane potential

Slide 9

  • Demonstrates the structure of the plasma membrane, with sodium and potassium ion channels
  • Shows differing ion concentrations inside and outside the membrane
  • Highlights the resting membrane potential of -70mV as a result of these concentration imbalances
  • Explains that resting membrane potential is NOT determined by the rate of ion movement, instead results of ion separations across the membrane

Slide 10

  • Resting membrane potential characteristics are summarized
  • Ion concentration differences and leak channel permeability are key factors
  • Resting potential is a prerequisite for generating electrical signals in neurons
  • Summary of ion concentrations and their roles in setting up the resting potential

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Quiz Team

Related Documents

Lecture 15 - Resting Membrane Potential PDF

Description

This quiz covers the essential concepts presented in Chapter 11 of your neuroscience textbook, focusing on the creation of electrical signals through membrane potential. It will test your understanding of neuron structure, membrane composition, and the roles of ions in establishing charge differences across membranes. Familiarity with Chapter 3 on cell membranes is also advised.

More Like This

Lec 21/22 SAQ - Neurons and Glia
40 questions

Lec 21/22 SAQ - Neurons and Glia

PrudentRainforest avatar
PrudentRainforest
Neuronal Electrical Activities
5 questions

Neuronal Electrical Activities

InestimableTurquoise avatar
InestimableTurquoise
Neuron Structure, Resting Membrane Potential and Action Potential Quiz
29 questions

Action Potential Quiz: Test Your Knowledge of Neuron Structure

StunningSpessartine avatar
StunningSpessartine
Introduction to Resting Membrane Potential
47 questions

Introduction to Resting Membrane Potential

GlamorousWashington avatar
GlamorousWashington
Use Quizgecko on...
Browser
Open
Browser
Browser