Chapter 8

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to Lesson

Podcast

Play an AI-generated podcast conversation about this lesson
Download our mobile app to listen on the go
Get App

Questions and Answers

Which type of receptor is involved when insulin binds to a cell to facilitate glucose entry?

  • Ligand-gated ion channels
  • Enzyme-linked receptors (correct)
  • G-protein-coupled receptors
  • Intracellular receptors

G-protein-coupled receptors are involved in stress responses, such as the release of epinephrine.

True (A)

What signaling molecule is involved in the stress response to increase glucose availability from glycogen?

Epinephrine

Insulin is secreted by _____ cells when glucose levels increase.

<p>pancreatic</p> Signup and view all the answers

Match the following receptors with their functions:

<p>Enzyme-linked receptors = Facilitate cellular response to insulin G-protein-coupled receptors = Mediate the stress response Ligand-gated ion channels = Increase muscle action during stress Intracellular receptors = Bind to lipid-soluble signaling molecules</p> Signup and view all the answers

Which ligand binds to intercellular receptors to stimulate the conversion of amino acids to glucose?

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

Insulin signals the cell to release glucose into the bloodstream for energy production.

<p>False (B)</p> Signup and view all the answers

What type of receptors do neurotransmitters bind to on muscle cells?

<p>ligand-gated ion channels</p> Signup and view all the answers

Epinephrine binds to ___________________ to signal the breakdown of glycogen.

<p>G-protein coupled receptors</p> Signup and view all the answers

Match the hormone with its corresponding receptor type:

<p>Insulin = Enzyme-linked receptors Cortisol = Intercellular receptors Epinephrine = G-protein coupled receptors Neurotransmitters = Ligand-gated ion channels</p> Signup and view all the answers

What is one reason cells need to respond to signals?

<p>To maintain homeostasis. (C)</p> Signup and view all the answers

Explain the function of nonpolar ligands in cellular communication.

<p>They diffuse through the membrane to reach intracellular receptors.</p> Signup and view all the answers

What are the three common stages of cell signaling?

<p>Receptor activation, signal transduction, and cellular response (C)</p> Signup and view all the answers

All living organisms require cell communication to survive.

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

What is the role of ligands in cell signaling?

<p>Ligands bind to receptors and cause conformational changes that activate the receptor.</p> Signup and view all the answers

Cells detect and respond to signals from their ______ and from other cells.

<p>environment</p> Signup and view all the answers

Match the following components of cell signaling with their functions:

<p>Receptor = Binds to signaling molecules Signal transduction pathway = Transmits the signal inside the cell Cellular response = Initiates a reaction in the cell Ligand = The signaling molecule</p> Signup and view all the answers

Which of the following can be considered a signal in cell communication?

<p>Both A and B (D)</p> Signup and view all the answers

Signal transduction occurs exclusively within the same cell.

<p>False (B)</p> Signup and view all the answers

Why is cell communication critical for multicellular organisms?

<p>It is essential for coordinating responses and functions among different cell types.</p> Signup and view all the answers

The process of ______ involves a group of proteins forming a signaling pathway in signal transduction.

<p>signal transduction</p> Signup and view all the answers

What is the Kd value indicative of?

<p>The concentration of ligand needed to bind to 50% of receptors (D)</p> Signup and view all the answers

A ligand-binding changes the receptor structure and transmits the signal across the membrane.

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

What happens to the receptor after the ligand is released?

<p>The receptor reverts to the inactive conformation.</p> Signup and view all the answers

Kd can also be considered the 'minimum effective dose' of ligand needed to __________.

<p>get a cell to respond</p> Signup and view all the answers

Match the following terms with their definitions:

<p>Kd = Dissociation constant indicating ligand affinity kon = Rate at which ligand binds to receptor koff = Rate at which ligand-receptor complex dissociates receptor = Protein that binds specific signaling molecules</p> Signup and view all the answers

Which of the following best describes high affinity ligands?

<p>They bind strongly and dissociate slowly from receptors (D)</p> Signup and view all the answers

At equilibrium, Kd is equal to koff divided by kon.

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

What is the significance of the ligand-receptor complex's stability?

<p>It ensures effective signal transduction during cellular communication.</p> Signup and view all the answers

The complex that forms between the ligand and its receptor is __________ for a finite period of time.

<p>stable</p> Signup and view all the answers

Flashcards

Cell Surface Receptors

Receptor proteins on the cell surface that bind to signaling molecules, initiating a chain of events inside the cell.

Enzyme-linked Receptors

A type of cell surface receptor that activates an enzyme within the cell upon binding to a signaling molecule.

G-protein-coupled Receptors

A type of cell surface receptor that uses a G-protein to relay signals to other proteins within the cell.

Ligand-gated Ion Channels

A type of cell surface receptor that opens a channel in the cell membrane, allowing ions to flow in or out of the cell.

Signup and view all the flashcards

Cell Signaling

The process of cells communicating with each other using signaling molecules.

Signup and view all the flashcards

Ligand

A molecule that binds to a specific receptor protein to initiate a cellular response.

Signup and view all the flashcards

Receptor

A protein that binds to a specific ligand, triggering a chain of events inside the cell, leading to a cellular response.

Signup and view all the flashcards

Intracellular receptors

Receptors located inside the cell that receive signaling molecules from within the cell.

Signup and view all the flashcards

Signaling Molecule (Ligand)

The molecule that binds to a receptor on the cell surface and initiates a signaling pathway.

Signup and view all the flashcards

Receptor Activation

The first step in cell signaling where a signaling molecule binds to its receptor.

Signup and view all the flashcards

Signal Transduction

The process of relaying a signal from the initial receptor to its target within the cell.

Signup and view all the flashcards

Cellular Response

The ultimate response of the cell to a signal, which could be changes in gene expression, protein activity, or cell behavior.

Signup and view all the flashcards

Signal Transduction Pathway

A chain of proteins that act as relays in the signal transduction pathway.

Signup and view all the flashcards

Why is Cell Communication Necessary?

Cell communication is crucial for survival, allowing cells to respond to environmental changes and coordinate their activity.

Signup and view all the flashcards

How do Cells Communicate?

Cells can communicate with their neighbors through direct contact or over long distances using secreted signaling molecules.

Signup and view all the flashcards

Receptor Affinity

A measure of how strongly a receptor binds to its signaling molecule (ligand). It's a dissociation constant (Kd), representing the concentration at which half of the receptors are bound to the ligand.

Signup and view all the flashcards

Ligand-Receptor Complex

A stable complex formed between a ligand and its receptor, lasting for a specific duration before dissociating.

Signup and view all the flashcards

On-Rate (kon)

The rate at which a ligand binds to its receptor. It's a measure of how quickly binding occurs.

Signup and view all the flashcards

Off-Rate (koff)

The rate at which a ligand detaches from its receptor. It's a measure of how quickly dissociation occurs.

Signup and view all the flashcards

Dissociation Constant (Kd)

The concentration of a ligand needed to bind to half of the receptors in a cell. It's a key indicator of how sensitive a cell is to that specific ligand.

Signup and view all the flashcards

Minimum Effective Dose

The amount of ligand required to elicit a measurable response in a cell, typically when at least 50% of the receptors are bound.

Signup and view all the flashcards

Study Notes

Cell Communication

  • Cells communicate to survive
  • Communication involves responding to incoming signals and sending outgoing signals
  • Signals can be chemical molecules or physical parameters like light or temperature
  • Cell communication is necessary for responding to a changing environment

Cell Signaling

  • A 3-step process
    • Receptor activation: A signaling molecule binds to a receptor causing a conformational change.
    • Signal transduction: The activated receptor initiates a series of proteins that form a signal transduction pathway.
    • Cellular response: The pathway affects cellular functions or protein amounts to produce a specific response.

Receptor Activation

  • Ligands (signaling molecules) bind to receptors with high specificity
  • Ligand binding changes the receptor structure, transmitting the signal
  • Once the ligand is released, the receptor reverts to its inactive form

Receptor Affinity

  • Affinity is measured by the dissociation constant (Kd)
  • Kd is the concentration of ligand needed for 50% of receptors to be bound
  • A lower Kd means higher affinity

Cell Surface Receptors

  • Most signaling molecules are small and hydrophilic or too large to pass through the plasma membrane
  • Cell surface receptors are embedded in the plasma membrane and detect extracellular signals
  • Three types of receptors
    • Enzyme-linked receptors
    • G-protein-coupled receptors
    • Ligand-gated ion channels

Enzyme-linked receptors

  • Have two domains: extracellular signal-binding and intracellular catalytic
  • They function as protein kinases.
  • They transfer a phosphate group from ATP to specific amino acids in target proteins to change protein shape and function.

G-protein-coupled receptors (GPCRs)

  • Interact with intracellular G proteins
  • Receptor activation causes the G protein's a subunit and βγ dimer to dissociate. Subunits then interact with other proteins.

Ligand-gated ion channels

  • When a signaling molecule binds, the channel opens, allowing ion flow across the membrane.

Intracellular Receptors

  • Found in the cytosol or nucleus
  • Bind small, hydrophobic signaling molecules that can diffuse across the plasma membrane.
  • Activation leads to a change in gene expression, typically via a change in transcription factor activity.
  • Steroid hormones like estrogen use these receptors.

Studying That Suits You

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

Quiz Team

Related Documents

Chapter 8 Lecture Notes on Cell Communication PDF

More Like This

Hormones, Receptors, and Cell Signals Quiz Part 2
14 questions

Hormones, Receptors, and Cell Signals Quiz Part 2

ExaltedCanyon98 avatar
ExaltedCanyon98
Hormone Receptor Effects Quiz
6 questions

Hormone Receptor Effects Quiz

IllustriousRocket avatar
IllustriousRocket
INTRODUCCIÓN SISTEMA ENDOCRINO
20 questions

INTRODUCCIÓN SISTEMA ENDOCRINO

AthleticHealing avatar
AthleticHealing
Use Quizgecko on...
Browser
Open
Browser
Browser