Bio 111 Chapter 9

which of the following are examples of cell-to-cell signaling

*contact-dependent signaling *endocrine signaling *direct intercellular signaling *paracrine signaling

the cellular level of communication involves

*receiving signals *sending signals *interpreting signals

select the three parts of the signal transduction pathway for epidermal growth factor (EGF)

*relay proteins *protein kinase cascade *transcription factors

what happens after activation of a G protein by a GPCR

*the g protein activates adenylyl cyclase *adenylyl cyclase synthesizes cAMP

what are the main advantages of second messengers in cellular signaling

*they increase the speed of intracellular signaling *they amplify the original signal

put the steps involved in a signal transduction cascade involving a G-protein-coupled reaction in the correct order

1. a ligand binds to a G-protein-coupled receptor 2. an intracellular G protein binds to GTP 3. adenylyl cyclase synthesizes cAMP 4. protein kinase A is activated 5. cellular proteins become phosphorylated and cause a cellular response

put the steps involved in the synthesis of diacylgylcerol and inositol triphosphate in the correct order

1. a ligand binds to its GPCR 2. A G protein is activated 3. phospholipase C is activated 4. a covalent bond in a phospholipid is broken

put the steps involved in a cell-to-cell signaling pathway in the correct order

1. binding of a signaling molecules to a receptor 2. intracellular signal transduction pathway 3. cellular response

put the stages of cell signaling in the correct order

1. receptor activation 2. signal transduction 3. cellular response

put the events that occur during the activation of a G-protein-coupled receptor in the correct order, beginning with the first event at the top

1. signaling molecule binds to a GPCR. 2. the GPCR binds to a G protein 3. the G protein exchanges GDP for GTP 4. the G protein subunits dissociate

put the steps of the signal transduction pathway activated by EGF in the correct order

1. the EDF receptor binds to EDF, dimerizes, and becomes phosphorylated 2. relay proteins become activated 3. ras releases GDP and binds GTP 4. a protein kinase cascade becomes activated 5. transcription factors become phosphorylated 6. genes encoding proteins that promote cell division are expressed

put the events that occur during EGF receptor activation in the correct order

1. two EGF receptor subunits each bind a molecule of EDF 2. two EGF receptor subunits dimerize 3. two EFG receptor subunits phosphorylate each other

some GPCRs stimulate the production of the second messengers ______ and _____ by phospholipase C

DAG and IP3

which of the following are used as intracellular second messengers?

DAG, Ca2+,Na+,IP3,cAMP

second messengers commonly used in cellular signaling include cAMP, Ca2+, ____ and ____

DAG, IP3

identify the intracellular proteins that bind guanosine triphosphate (GTP) and guanosine diphosphate (GDP)

G proteins

the binding of a signal molecule to a __________ leads to activation of adenylyl cyclase. They resulting increase in cAMP activates PKA which phosphorylates specific cellular proteins to cause a cellular response

G-protein-coupled receptor

what types of receptors mediates the signal transduction pathway involving cAMP

G-protein-coupled receptor

when a GPCR is activated, it causes the G protein to release _________ and bind ________

GDP, GTP

during the fourth step in the signal transduction pathway involving cAMP, the phosphorylation of specific cellular protein by _________ causes a cellular response

PKA

what event does not occur after the activation of a G-protein coupled receptor

a G protein hydrolyzes GTP to GDP

contact-dependent signaling

a membrane-bound signaling molecule binds to a receptor on the surface of another cell

what does the binding of a signaling molecule to its receptor stimulate

a signal transduction pathway

endocrine signaling

a signaling molecule acts on target cells distant from the cell that secreted the signals

paracrine signaling

a signaling molecule affects targets cells nearby but not the cell that secreted the signal

autocrine signaling

a signaling molecule binds to a receptor on the same cell that secreted the signal

direct intercellular signaling

a signaling molecule passes between the cytosol of adjacent cells through a cell junction

the change that occurs when a signaling molecule binds to the extracellular domain causes the catalytic domain to become

activate

genes encoding proteins for cell division.

activated transcription factors

Cyclic AMP is synthesized by

adenylyl cyclase

select all of the following that are the result of cell signaling causing the rearrangement of actin filaments, which are structural proteins

an amoeba moving toward food, animal cells moving during embryonic development

G-protein-coupled receptor

an intracellular G protein release GDP and binds to GTP

in _________ signaling, cells release signals that affect themselves and nearby target cells

autocrine

in ___________ signaling, the same cell that secretes a signaling molecule responds to it

autocrine

cell-to-cell communication can occur via different mechanisms. in ___________ signaling, a cell can respond to its own signal. in __________ signaling, a secreted signaling molecule affects nearby target cells but not the cell that secreted the signal. in __________ signaling, the signaling molecule can affect cells at a distance from the cell that secreted the signal

autocrine, paracrine, endocrine

after ligand binding, the EGF receptor becomes activated through the phenomenon of

autophosphorlaytion

calmodulin

binding of Ca2+

protein kinase C

binding of Ca2+ and DAG

EGF recptor

binding of EDF

G protein

binding of GTP

Ras

binding of GTP

ligand-gated Ca2+ channel on the ER

binding of IP3

phospholipase C

binding of a G protein

the enzyme adenylyl cyclase, which synthesizes cAMP, is stimulated by

binding of the a subunit of a G protein

various GPCRs can stimulate the production of

cAMP, DAG and IP3

a protein kinase ________ involves the sequential activation of multiple protein kinases

cascade

adaption at the cellular level is called a

cellular response

what does the interaction between a signal and its receptor elicit?

cellular response

when ligands after the structure of their receptors, this causes an

conformational change

during ________ dependent signaling, membrane-bound signals bind to receptors on adjacent cells

contact

which type of cell-to-cell communication involves signaling molecules that do not diffuse readily from one cell to another

contact-dependent signalling

what second messengers are produced by phospholipase C?

diacylglycerol, inositol triphosphate

different cell types may respond to the same hormone differently due to

differential gene expression, different affinities of receptors for the same signaling molecule

second messengers increase the speed of cellular signaling because they

diffuse through the cytosol rapidly

in the EGF pathway, the cellular response to the activation of transcription factors is to stimulate the cell to

divide

in _____________ signaling, cells release signals that travel long distances to affect target cells

endocrine

cell signaling allows cells to detect and respond to signals from their _____________ and from other cells

environment

cell signaling is important for cells to be able to respond to a changing _________ and to __________ with each other

environment, communication

which of the following are types of cell surface receptors?

enzyme-linked receptor, ligand-gated ion channel, g-protein-coupled receptor

three common categories of proteins that are controlled by cell signaling are

enzymes, transcription factors, structural proteins

the formula, Kd = [ligand], represents a ligand concentration where ______ of the receptors have bound ligands

half

GPCR

heart muscle cells

in both animals and plants, molecules involved in long-distance signaling are called

hormones

cellular receptors can be located

inside the cell, on the cell surface

identify the proteins that allow the diffusion of ions across cellular membranes

ion channels

Ligand-gated ion channel

ions move across the plasma membrane of the cell

how does EGF released from one cell reach its receptor on another cell

it travels through the blood

what term is used to describe a signaling molecule

ligand

when a signaling molecule binds to a(n) ___________-gated ion channel, the channel opens and allows the flow of ions through the membrane

ligand

ligand-gated ion channel

muscle cells

a ligand binds __________ to its receptor with a high degree of specificity

noncovalently

in contact-dependent signaling, where is the signaling molecule located

on the membrane of a cell

MAP-kinases

phosphorylation

cell surface receptors are receptors found in the ______ membrane

plasma

some signaling molecules must pass through the ________________ _________________ before activating a receptor located in the cytosol or the nucleus

plasma membrane

in hormonal signaling, the variation in a cellular response is determined by the type of ________ that each cell type makes

proteins

cellular signaling involves an interaction between a signaling molecule from one cell and a ________ on or in another cell

receptor

communication of the cellular level involves receiving and sending signals as well as their interpretation. for this to occur, a signal must be recognized by a cellular protein called a

receptor

what is the first step in cell signaling

receptor activation

cell signaling is necessary for cells to

respond to a changing environment, communicate with one another

cells can use different types of __________ messengers in response to extracellular signals

second

second messenger signaling is typically of _____ duration

short

cell communication, also called cell __________, involves both incoming and outgoing signals

signaling

a growth factor is a type of

signaling molecule

communication at the cellular level involves sending, receiving, and interpreting

signals

what happens when a signaling molecule binds to a ligand-gated ion channel

the channel protein binds to other channel proteins

steroid hormone receptor

the receptor binds to DNA and activates the transcription of specific genes

enzyme-linked receptor

the receptor phosphorylation itself or another protein

what enables different cell types to respond to the same hormone in a different way

they may activate different intracellular signal transduction pathways in response to the same signal, they may have different receptors for the same signaling molecule, they may express different proteins controlled by signal transduction pathways

EGF receptor signaling leads to the activation of _______ factors, which stimulate the expression of specific genes

transcription

the specific cellular proteins phosphorylated by the catalytic subunit of PKA are

transcription factors, structural proteins

in signal __________, the initial signal is converted to a different signal inside the cell

transduction

signaling molecules exert their effects on cells through signal _________ pathways

transduction