Biology Chapter 11: Cell Communication (2/2)

Summary

This YouTube video script delves into cell communication, focusing on the three stages: reception, transduction, and response. It explains how signaling molecules initiate communication by binding to receptor proteins on the cell surface, triggering a conformational change. Key receptor types like G protein-coupled receptors, receptor tyrosine kinases, and ion channel receptors are discussed. The script then details the transduction process, emphasizing the role of phosphorylation and dephosphorylation in signal amplification and regulation. Finally, it touches on the response stage, where signals regulate cellular activities like transcription or cytoplasmic functions, ensuring precise cellular responses.

Takeaways

• 🔬 Cell communication involves three stages: reception, transduction, and response.
• 🔔 Reception is the initial stage where a signaling molecule binds to a receptor protein, causing a conformational change.
• 🔄 Receptor proteins are typically transmembrane and have specific shapes and chemical properties to bind only to certain signaling molecules.
• 🔗 G protein-coupled receptors interact with G proteins to relay messages inside the cell upon ligand binding.
• 📡 Receptor tyrosine kinases (RTKs) become activated upon ligand binding, leading to dimerization and activation of the kinase activity.
• 🚪 Ion channel receptors act as gates for ions to move across the cell membrane, activated by ligand binding or membrane potential changes.
• 📈 Intracellular receptors, found within the cell, require signaling molecules to pass through the plasma membrane to bind and initiate a response.
• 🔄 Transduction involves a cascade of molecular interactions that relay signals from receptors to their targets, often involving phosphorylation events.
• ⚙️ Phosphorylation and dephosphorylation are key mechanisms in regulating protein activity and signal transduction within cells.
• 🏁 The response stage is the final step where the signal transduction pathway leads to the regulation of cellular activities, such as gene transcription or protein synthesis.

Q & A

What are the three stages of cell communication?

The three stages of cell communication are reception, transduction, and response.

What happens during the reception stage of cell communication?

During the reception stage, a signaling molecule binds to a receptor protein, causing it to change shape and initiating a series of intracellular signaling events.

What is the role of receptor proteins in cell communication?

Receptor proteins play a crucial role in cell communication by binding to specific signaling molecules and initiating a response within the cell.

How does the binding of a signaling molecule to a receptor protein cause a conformational change?

The binding of a signaling molecule to a receptor protein causes a conformational change by interacting with the extracellular domain of the receptor, which then alters its shape and activates the intracellular domain to interact with signaling proteins.

What are the different types of receptor proteins mentioned in the script?

The script mentions G protein-coupled receptors, receptor tyrosine kinases, and ion channel receptors as different types of receptor proteins.

How do G protein-coupled receptors work?

G protein-coupled receptors work by interacting with G proteins upon ligand binding, which leads to a conformational change that activates the intracellular signaling pathway.

What is the role of receptor tyrosine kinases in cell communication?

Receptor tyrosine kinases play a role in cell communication by activating their intrinsic kinase activity upon ligand binding, leading to receptor dimerization and the initiation of intracellular signaling.

How do ion channel receptors contribute to cell communication?

Ion channel receptors contribute to cell communication by acting as gates for the movement of ions across the cell membrane in response to ligand binding or changes in membrane potential.

What is the purpose of the transduction stage in cell communication?

The transduction stage is where a series of molecular interactions relay signals from receptors to their targets, often involving multi-step pathways that amplify the signal and provide control points for regulation.

What is the role of phosphorylation and dephosphorylation in cell signaling?

Phosphorylation and dephosphorylation play a critical role in regulating protein activity and signal transduction by adding or removing phosphate groups, which can activate or inhibit enzymes and affect protein conformation.

How does the response stage of cell communication lead to cellular activities?

The response stage leads to cellular activities by regulating protein synthesis or other cytoplasmic activities, often through the activation of transcription factors that turn genes on or off.

Outlines

00:00

🔬 Introduction to Cell Communication

The script begins by introducing the topic of cell communication, specifically focusing on chapter 11. The presenter, Iman, recaps the previous discussion on self-communication and the three stages of cell communication: reception, transduction, and response. The current session aims to delve deeper into each stage, starting with reception. Reception is defined as the first step where a signaling molecule, or ligand, binds to a receptor protein on the cell surface, causing a conformational change. This change initiates intracellular signaling events. Receptor proteins are transmembrane proteins with specific shapes and chemical properties that allow them to bind only to specific signaling molecules, likened to a lock-and-key mechanism. The ligand binds to the extracellular domain of the receptor, triggering a conformational change that sends a message to the intracellular part of the cell, setting off the next steps in the communication process.

05:00

🧬 Receptor Proteins and Their Functions

This paragraph discusses different types of receptor proteins involved in cell signaling. The first type mentioned is G protein-coupled receptors (GPCRs), which are transmembrane proteins that interact with G proteins upon ligand binding, leading to a conformational change and activation of intracellular signaling pathways. G proteins function as molecular switches, changing from an inactive GDP-bound state to an active GTP-bound state upon receptor activation. The activated G protein then interacts with and activates an enzyme, initiating a series of events that culminate in a cellular response. The temporary nature of this activation is due to the G protein's ability to hydrolyze GTP back to GDP, resetting the process. The paragraph also introduces receptor tyrosine kinases (RTKs) and ion channel receptors, setting the stage for further discussion on their roles in cell signaling.

10:01

🌐 Ion Channel Receptors and Intracellular Receptors

The script continues by explaining ion channel receptors, which are transmembrane proteins that control the flow of ions across the cell membrane. These receptors can be activated by ligand binding or changes in membrane potential, leading to the opening of ion channels and the flow of ions like sodium, potassium, or calcium. The paragraph also discusses intracellular receptors, which are found within the cell, either in the cytoplasm or the nucleus. Signaling molecules must pass through the plasma membrane to reach these receptors. Once inside, they can bind to intracellular receptors, initiating a response that may involve gene regulation. The paragraph emphasizes the multi-step nature of signal transduction, which allows for signal amplification and regulation, ensuring a coordinated and controlled cellular response.

15:02

🔋 Phosphorylation and Dephosphorylation in Signal Transduction

This section delves into the mechanisms of phosphorylation and dephosphorylation, which are critical for regulating protein activity and signal transduction within cells. Phosphorylation, the addition of a phosphate group to a protein by a kinase enzyme, can activate or inhibit enzyme activity, change protein conformation, or affect protein localization. Dephosphorylation, carried out by phosphatases, is a reversible process that removes phosphate groups. These processes are key components of intracellular signaling pathways, allowing for the conversion of extracellular signals into a series of intracellular events leading to a cellular response. The paragraph uses a phosphorylation cascade as an example to illustrate how a signaling event can initiate a series of phosphorylation events, culminating in a cellular response.

20:02

🌀 The Final Stage: Cellular Response

The final paragraph discusses the response stage of cellular communication, where signal transduction pathways lead to the regulation of cellular activities. These activities can occur in the nucleus or cytoplasm and involve the regulation of protein synthesis or gene expression. The response is not a simple on-off switch but is regulated in multiple ways, including amplification of the signal, control points for regulation, enhancement through proteins like scaffolding proteins, and the termination of the signal. The paragraph emphasizes the importance of these regulatory mechanisms in ensuring that cells function correctly and that the right amount of substances, such as proteins and enzymes, are produced. The discussion concludes with a summary of the three stages of cell communication: reception, transduction, and response, highlighting the importance of communication in cellular processes.

Keywords

💡Cell Communication

Cell communication is the process by which cells send and receive signals to coordinate their functions. It is a fundamental aspect of biology, allowing cells to interact with each other and their environment. In the video, cell communication is broken down into three stages: reception, transduction, and response, which are essential for understanding how cells function and interact within an organism.

💡Reception

Reception is the first stage of cell communication where a signaling molecule, or ligand, binds to a specific receptor protein on the surface of a target cell. This binding causes a conformational change in the receptor protein, initiating a series of intracellular signaling events. The video explains that this is akin to a 'lock and key' mechanism, ensuring specificity in the interaction between signaling molecules and receptor proteins.

💡Transmembrane Proteins

Transmembrane proteins are proteins that span across the cell membrane, with parts of the protein exposed to both the extracellular environment and the intracellular space. These proteins play a crucial role in cell communication by acting as receptors for signaling molecules. The video mentions that receptor proteins are typically transmembrane proteins that interact with signaling molecules on the cell surface.

💡Conformational Change

A conformational change refers to a change in the shape or structure of a molecule, often resulting from interactions with other molecules. In the context of the video, when a signaling molecule binds to a receptor protein, it causes a conformational change in the receptor. This change is critical as it initiates the intracellular signaling cascade, which eventually leads to a cellular response.

💡G Protein-Coupled Receptors (GPCRs)

GPCRs are a large family of transmembrane proteins that play a critical role in cell signaling. They are named for their interaction with G proteins, a class of intracellular signaling proteins. The video describes how GPCRs, upon ligand binding, undergo a conformational change that activates the G protein, leading to a series of intracellular signaling events.

💡Receptor Tyrosine Kinases (RTKs)

RTKs are another type of transmembrane protein involved in cell signaling. They have intrinsic protein kinase activity that is activated upon ligand binding. The video explains that RTKs can form dimers upon ligand binding, which activates their kinase activity, leading to the phosphorylation of intracellular proteins and the initiation of signaling pathways.

💡Ion Channel Receptors

Ion channel receptors are transmembrane proteins that function as gates for the movement of ions across the cell membrane. They can be activated by specific ligand binding or changes in membrane potential. The video mentions that when activated, these receptors allow ions like sodium, potassium, or calcium to flow across the membrane, which can trigger cellular responses.

💡Intracellular Receptors

Intracellular receptors are proteins found within the cell, either in the cytoplasm or the nucleus. Unlike membrane-bound receptors, signaling molecules must enter the cell to interact with these receptors. The video notes that these receptors can be activated by hydrophobic molecules, such as steroid hormones, or small molecules like nitric oxide, which can pass through the cell membrane.

💡Transduction

Transduction refers to the process by which a signal is relayed from the cell surface to the interior of the cell, often involving a series of molecular interactions. The video describes transduction as a multi-step pathway that amplifies the signal and can involve the activation of proteins through phosphorylation or the release of small molecules that act as messengers.

💡Phosphorylation

Phosphorylation is a post-translational modification where a phosphate group is added to a protein, typically by a kinase enzyme. This process can activate or inhibit enzyme activity, regulate protein localization, or target proteins for degradation. The video emphasizes that phosphorylation and dephosphorylation are key mechanisms in intracellular signaling transduction pathways.

💡Response

The response is the final stage of cell communication, where the signal transduction pathway leads to the regulation of cellular activities. This can occur either in the nucleus,调节基因表达, or in the cytoplasm,调节其他细胞活动. The video explains that the response can involve the activation or inhibition of genes, protein synthesis, or other cellular processes, ensuring that the cell carries out the necessary actions in response to the signal.

Highlights

Introduction to cell communication chapter 11.

Explanation of the three stages of cell communication: reception, transduction, and response.

Reception is the first step where a signaling molecule binds to a receptor protein causing a conformational change.

Receptor proteins are typically transmembrane proteins with specific shapes and chemical properties for binding.

The binding of signaling molecules to receptors is likened to a lock and key mechanism.

Conformational change in the receptor protein initiates intracellular signaling events.

Types of receptor proteins include G protein-coupled receptors, receptor tyrosine kinases, and ion channel receptors.

G protein-coupled receptors interact with G proteins to relay messages upon ligand binding.

Receptor tyrosine kinases have intrinsic kinase activity activated upon ligand binding.

Ion channel receptors act as gates for ion movement across the cell membrane.

Intracellular receptors are found within the cell and are activated by signaling molecules that pass through the plasma membrane.

Transduction is the multi-step pathway that relays signals from receptors to their targets.

Phosphorylation and dephosphorylation are key mechanisms in regulating protein activity and signal transduction.

The transduction pathway can amplify the signal through a series of molecular interactions.

The response stage is the final step where the signaling pathway leads to the regulation of cellular activities.

Signaling pathways can regulate protein synthesis by turning genes on or off.

The final activated molecule can function as a transcription factor to regulate gene expression.

Regulation of the response includes amplification, control points, efficiency enhancement, and signal termination.

Summary of cell communication stages: reception, transduction, and response.

Transcripts

hello everybody my name is Iman welcome

back to my YouTube channel today we're

continuing chapter 11 cell communication

last time we sort of motivated the idea

of self communication we introduced the

three stages of cell communication which

is a reception transduction and response

and today we want to dive into the

details of each of these stages starting

off with stage one reception all right a

signaling molecule binds to a receptor

protein causing it to change shape so

let's dive into this all right reception

like we said is the first step in cell

signaling where a signaling molecule or

ligand ligand sorry binds to a specific

receptor protein usually located on the

surface of the target cell all right The

Binding of the signaling molecule to the

receptor protein is going to cause a

conformational change in that receptor

protein at I did too and what this does

is it initiates a series of

intracellular signaling events now

receptor proteins they're typically

transmembrane or plasma membrane

proteins that will span the cellular

membrane

with an extracellular domain that binds

to the signaling molecule and an

intracellular domain that will interact

with intracellular signaling proteins

all right the extracellular domain of

the receptor protein it usually has a

specific shape and a specific chemical

properties that are going to allow it to

bind to only specific signaling

molecules all right so it kind of works

like a lock and key mechanism all right

so what we're saying is that these

receptor proteins usually found

um

in the plasma membrane can have a

extracellular component a part of it

that kind of peeks out of the membrane

and a part of it that's embedded in the

membrane usually the outer part of this

this receptor protein will interact with

with with a signaling molecule they have

specific shapes so that they only bind

to specific signaling molecules all

right

so there there's usually a specificity

to receptor proteins that they're only

binding to the kind of signaling

molecules that they bind to that they

can respond to all right now the

signaling molecule lands in the receptor

protein that it needs to get to all

right in the extracellular part and then

a conformational change happens some

sort of conformational change happens

right like uh it changes all right this

change

in itself

lets the cell know

all right sends a a message the change

in the receptor protein carries a

message with it it carries a message to

the intracellular part of of the cell to

to enact something right

that's going to be the next step

essentially but this reception part all

right you have a signaling molecule that

will interact with its specific receptor

protein these are usually like I said

transmembrane or plasma membrane

proteins that will span the cell

membrane all right and the extracellular

domain the extracellular part of that

receptor protein is going to have a

specific shape in chemical properties

that will allow it to only bind to

specific signaling molecules now

The Binding of the signaling molecule to

the receptive protein protein is going

to induce a conformational change in the

receptor Protein that's going to either

activate or inhibit the intracell the

intracellular signaling pathway all

right it's either gonna

activate some further steps that happen

within the the the inside part of the

cell the intracellular uh on part of the

cell or it's going to inhibit some

signaling pathway inside of the inside

of the cell this conformational change

may involve the rearrangement of

intramolecular bonds or the the exposure

of previously hidden domains that will

interact with intracellular signaling

proteins so this change in this receptor

protein can then send

um

signals to proteins that happen to lie

inside of the cell to carry the message

all right now with that being said let

me erase this all right with that being

said there are some important types of

receptor plasma membrane proteins that

we want to just talk about a little bit

all right one of them is called a g

protein coupled receptors another type

that we'll talk about

um are receptor tyrosine kinases and the

third type that we'll we'll briefly talk

about are ION channel receptors all

right now

first we'll start with

G protein coupled receptors all right

these are a large and diverse family of

transmembrane proteins that play a

really critical role in cell signaling

and they're named this way because they

interact with a class of intracellular

signaling proteins called G proteins

all right so this trans membrane protein

g-protein-coupled receptor Works

alongside other G proteins that are

inside the cell to relay

um

to relay messages so upon ligand binding

the receptor is going to undergo a

conformational change which activates

the intracellular signaling pathway

inside the cell to relay the message so

here let's read let's read the steps

that they break down here this Loosely

attached to the cytoplasmic side of the

membrane the G protein functions as a

molecular switch that is either on and

off depending on which of the two

guanine nucleotides are attached all

right

now when GDP is bound to the G protein

as shown above the G protein is inactive

the receptor and the g protein work

together with another protein usually an

enzyme now when the appropriate

signaling molecule finally binds to this

G protein-coupled receptor all right the

receptor is activated and what happens

is it changes shapes it's cytoplasmic

side the inside part of this protein

then binds to an inactive G protein all

right so in its inactive form

all right the G protein-coupled receptor

and the g protein themselves they're not

bound together

all right but when a signaling molecule

comes ahead and binds to this

g-protein-coupled receptor it sends it

relays a message that leads to the G

protein being binded to the

g-protein-coupled receptor and it

activates the G protein what happens

when the G protein is activated well the

activated G protein dissociates from the

receptor diffuses along the membrane and

then binds to an enzyme altering the

enzymes shape and activity so then

um

it moves and binds to an inactive

enzyme and this enzyme becomes activated

once activated the enzyme can trigger

The Next Step leading to a cellular

response all right now the changes in

the enzyme and the g protein are only

temporary because the G protein also

functions as a gtpase enzyme in other

words it then hydrolyzizes its bound GTP

to GTP and now it's inactive again

allowing this whole process to be

repeated if need be

all right so that's one kind of receptor

protein the G protein-coupled receptor

fantastic another kind of receptor

protein is this tyronease kinases these

receptor tyrosine kinases I'm sorry

they're also a family of transmembrane

proteins that play a critical role in

cell signaling and they're named this

way because they have intrinsic protein

kinase activity which is activated upon

ligand binding to the receptor let's

also work through this figure all right

so many receptor thyroidase kinases have

the structure that's depicted here all

right these are two these are receptor

Tyrone tyrosine kinase proteins I'm so

sorry

all right

um before the signaling molecule binds

the they exist as individual units all

right so this is one

um rtk uh protein and this is another

rtk protein I'm going to use the acronym

all right notice that each of them has

an extracellular ligand binding site

they each exist as different units and

they each have a binding site

all right Now The Binding of a signal

signaling molecule to one of these

causes the two receptor monomers or

actually The Binding of signal molecules

to both of these

um like a growth factor causes the two

receptor monomers to associate closely

with each other and they form a complex

that we now call a rtk dimer

all right this dimerization activates

the TK uh the tyrosine kinase region of

each monomer each tyranny tyrosine

kinase then adds a phosphate from an ATP

molecule to a tyrosine on the tail of

the other monomer all right and now the

receptor is fully activated and it is

recognized by specific relay proteins

inside the cell to relay the message

each activated protein triggers a

transduction pathway that leads to a

cellular response alright so this is

another example of a receptor protein

our last example are these ION channel

receptors they're also transmembrane

proteins that act as a gate for the

movement of ions across the cell

membrane they're activated by binding of

a by binding of a specific ligand ligand

or by changes in membrane potential too

so when they're activated an ion Channel

receptor will usually allow ions like

sodium potassium calcium to flow across

the membrane either into or out of the

cell all right so here what we see is we

see the ligand-gated Ion channel

receptor where the the gate is closed

until you have a signaling molecule that

comes and binds to the Ion channel and

this signaling molecule will result in

the Ion channel opening and allowing

ions to pass through in One Direction or

the other

all right fantastic so those are three

examples of receptor proteins now there

are other kinds of receptor specifically

intracellular receptors intracellular

receptor proteins are receptor proteins

you'll find inside the cell not

necessarily just in the membrane right

there's other kinds of receptors

um these intracellular receptors are

found in either the cytoplasm or the

nucleus of target cells and to reach a

uh such a receptor right because they're

not on the membrane

um they're inside the cell what happens

is

a signaling molecule has to pass through

the target cells plasma membrane to

reach these intracellular receptors a

number of important signaling molecules

can do this because they are either

hydrophobic enough to pass through the

plasma membrane or they're small enough

to enough to cross the hydrophobic

interior of a membrane all right these

hydrophobic chemical Messengers can

include things like steroid hormones and

thyroid hormones of animals and another

chemical signaling molecule with a

intracellular receptor is nitric oxide

and gas it's a very small molecule that

can readily pass through the membrane's

phospholipids now regardless once the

signaling molecule or hormone has

entered the cell it can then bind to an

intracellular receptor in the cytoplasm

or the nucleus

and of course the binding changes the

receptor into some sort of complex

that's going to be able to cause a

response many cases this can be turning

on or off of particular genes

all right so that's the first stage of

cell communication all right let's move

on to our next objective which is

talking about the second

um stage of cellular communication this

is transduction all right Cascades of

molecular interactions can then relay

signals from receptors to their targets

so when receptors for signaling

molecules are plasma membrane proteins

like most of those we've discussed then

the transduction cell stage of a cell

signaling is usually a multi-step

pathway that involves many molecules and

it usually happens inside this cell so

steps often include the activation of

proteins by either the addition or

removal of phosphate groups or something

like the release of other small

molecules or ions that will act as

Messengers one benefit of this

multi-step

transduction pathway is the possibility

of greatly amplify buying a signal so if

each molecule in this pathway transmits

the signal to numerous molecules at the

next step in the series then the result

is a geometric increase in the number of

activated molecules by the end of the

pathway and so multi-step Pathways

provide more opportunities for

coordination and control than do simple

systems and this really allows for the

regulation of a response

and so like we said the first step is

reception your signaling molecule will

bind to a receptor protein this is going

to have some change to this receptive

protein and this results in

the a couple of next steps that we call

transduction that will continue to

happen until the message finally reaches

its Target all right most of the time it

involves multiple steps it's not usually

a one-step thing and again like we said

this is usually a good thing it's good

that it's multi-step because that means

more molecules in each step are

activated making sure that there's a

geometric increase in the number of

activated molecules through this pathway

ensuring that the target reaches the

response it needs

all right now the phosphorylation and

dephosphorylations of protein is a

widespread as a widespread cellular

mechanism for regulating protein

activity and transducing a a message so

let's talk about this a little more now

phosphorylation and dephosphorylation

are key mechanisms of post-translational

Pros post-translational modification

that actually regulates protein activity

and it's usually very critical it's a

very critical component of intracellular

signaling transductions so if you're

wondering okay we understand reception

you have a signaling molecule that binds

to your receptor protein it changes and

then that somehow initiates a

transduction multi-step Pathway to to

relay the message all right but what is

what is happening usually in those

transduction steps well one thing that

usually happens is phosphorylation and

dephosphorylation of proteins these are

the key mechanisms of how

how

intracellular signal transduction

pathways are are are moved along

phosphorylation usually involves the

addition of a phosphate group to a

protein typically like a c serine or

threonine or a tyrosine residue and it's

usually done by an enzyme called a

kinase this process is usually

reversible it can be counteracted by an

enzyme

um called phosphatase which removes the

phosphate group from the protein and so

phosphorylation dephosphorylation that's

a reversible process

now like we said phosphorylation and

defosphorylation it plays a critical

role in cell signaling by regulating the

activity of enzymes

um by regulating the activity of enzymes

as we move through a transduction

pathway for example

um

phosphorylation can activate or inhibit

enzyme activity by changing the

conformation of the protein or by

creating or disrupting docking sites for

other signaling proteins phosphorus

phosphorylation can also regulate the

subcellular localization of proteins or

or Target them for degrade degradation

all right so essentially this process of

phosphorylation dephosphorylation is a

really key component of intracellular

signaling transduction Pathways where

your extracellular signal or stimuli is

converted into a series of intracellular

signaling events that finally lead to a

cellular response okay one more time

because this is really important and

it's probably a very new idea that

you're learning here

okay let's erase this and let's work

through this figure all right we know we

understand reception now let's Circle

this in purple this is our reception

step signaling molecule binds to the

receptor protein causes a change and it

initiates a transduction pathway all

right this transduction pathway is

usually several steps all right this is

one example of a phosphorylation Cascade

all right which is an example of a

transduction pathway that can happen all

right what you can have here is you can

have a relay molecule that activates

protein kinase one

all right so this this change in your

receptor protein

results in this activated relay molecule

that interacts with this inactive

protein kinase when these two things

interact what happens oh what happens is

now we have an active protein kinase one

all right now this active protein kinase

one what can it do it can transfer a

phosphate from ATP to an inactive

molecule of protein kinase II all right

so what

what what kinase one does is

it adds a phosphate group to kinase II

and now kinase II is also an activated

protein okay what does kinase 2 do it

does it initiates another

phosphorylation where we take one

phosphate group from ATP slap it onto

kinase 3 and now kinase 3 is also

activated and finally this kinase 3 it

brings the cell

uh signal the cellular message to our

active protein our Target protein

finally which will finally result in a

cellular response which is the final

stage of cellular communication

all right fantastic that leads us to

actually being able to talk to our

finals talk about our final stage of

cellular communication and that's the

response stage cell signaling leads to a

regulation of either transcription or

other cytoplasmic activities so now what

we can do is take a closer look at the

cell's subsequent response to an

extracellular signal all right this is

what some researchers call the output

response what is the nature of the final

step in the signaling pathway ultimately

a signal transduction pathway leads to

the regulation of one or more cellular

activities the response at the end of

the pathway can occur either in the

nucleus or the cytoplasm but the point

is that fine that response

tells the Targets target molecule or

Target organelle or Target

um

protein that it needs to go and do a

specific thing and that specific thing

keeps the cell working in the way that

it needs to all right ultimately keeping

your bodies working the way that they

need to all right many signaling

Pathways will regulate protein synthesis

usually by turning G's on or off in the

nucleus all right like an activated

steroid receptor the final activated

molecule in a signaling pathway can also

function as a transcription Factor all

right it can

um

it can signal transcription the

synthesis of one or more specific mrnas

which will be translated into the

cytoplasm into specific proteins it can

regulate

um

many different things in this cell all

right and as for regulation of a signal

whether the response occurs in the

nucleus or the cytoplasm it's not just

simply turned on and off rather the

extent and the specificity of this

response are regulated in multiple ways

all right and here we'll consider four

aspects of this regulation actually

first signaling Pathways generally

amplify the cell's response to a single

signaling event and the degree of

amplification depends on the function of

the specific molecules in the pathway

all right second the many steps in a

multi-step pathway provide control

points at which the cell's response can

be further regulated which contributes

to the specificity of the response and

it allows for coordination with other

signaling pathways

third the overall efficiency of the

response is enhanced by the presence of

proteins like scaffolding proteins and

finally a crucial point in regulating

the response is the termination of the

signal all right

so the way that the signal passes

through the transduction uh pathway and

and reaches its Target cell and then

communicates some sort of of job that

the cell needs to do is is ultimately

important in in regulating different

things within the cell that keep the

cell functioning that keep the cell

alive

um

and it's important for the synthesis of

things like proteins and enzymes all

right so most signaling Pathways

ultimately regulate things like protein

synthesis or turn genes on and off all

right the final activated molecule can

function even as a transcription factor

and ultimately everything's regulated

all right everything's regulated through

communication so enough of something is

produced and not too much all right

and and so on and so forth all right so

that's cell communication for us

reception transduction and finally

response I hope this was helpful let me

know if you have any questions down

below other than that good luck happy

studying and have a beautiful beautiful

day