Cell Communication (Chapter 9)

Question 1

Ligand

Answer 1

The signaling molecule

Question 2

Receptor Protein

Answer 2

The molecule to which the receptor binds.

- May be on the plasma membrane or within the cell.

Question 3

Receptor proteins have a _____ shape that fits a specific _____.

Answer 3

three-dimensional

signal molecule

Question 4

When a signal molecule and receptor protein bind, a change in the _____ is induced and a _____ in the cell is generated.

Answer 4

receptor protein

response

Question 5

A(n) _____ arises from a ligand binding to a receptor.

Answer 5

conformational change

Question 6

The _____ can directly or indirectly interact with a whole host of other _____ within the cell.

Answer 6

receptor-ligand complex

signaling molecules

Question 7

Cell signals can be induced through _____, _____, _____ (_____), and _____ (_____).

Answer 7

Direct contact
Paracrine signaling
Endocrine signaling
-(hormones)
Synaptic signaling
-(neurotransmitters)

Question 8

Cell Communication Through Direct Contact

Answer 8

Molecules on the surface of one cell are recognized by receptors on the adjacent cell.

Question 9

Cell Communication Through Paracrine Signaling

Answer 9

A signal released from a cell has an effect on neighboring cells.

Question 10

Cell Communication Through Endocrine Signaling

Answer 10

Hormones released from a cell affect other cells throughout the body.

Question 11

Cell Communication Through Synaptic Signaling

Answer 11

Nerve cells release the signal (neurotransmitter) which binds to receptors on nearby cells.

Question 12

Signal Transduction

Answer 12

Occurs when a ligand binds to a receptor protein, creating a response.

Question 13

During signal transduction, different _____ can respond differently to the same signal.

Answer 13

cell types

Question 14

A cell’s response to a signal often involves _____ or _____ proteins.

Answer 14

activating

inactivating

Question 15

_____ is a common way to change the activity of a protein.

Answer 15

Phosphorylation

Question 16

Protein Kinase

Answer 16

An enzyme that adds a phosphate to a protein.

Question 17

Phostatase

Answer 17

An enzyme that removes a phosphate from a protein.

Question 18

Two different classes of protein kinases:

Answer 18

Serine/Throenine

Tyrosine

Question 19

Receptors can be defined by their _____.

Answer 19

location

Question 20

Intracellular Receptor

Answer 20

Located within the cell.

Question 21

Cell Surface Receptor

Membrane Receptor

Answer 21

Located on the plasma membrane to bind a ligand outside the cell.

Question 22

Three subclasses of membrane receptors:

Answer 22

Channel linked receptors
Enzymatic receptors
G protein-coupled receptor (GPCR)

Question 23

Channel Linked Receptors
(Membrane Subclass Receptor)

Answer 23

Ion channel that opens in response to a ligand.

Question 24

Enzymatic Receptors
(Membrane Subclass Receptor)

Answer 24

Receptor is an enzyme that is activated by the ligand.

Question 25

``` G Protein-Coupled Receptor (GPCR) (Membrane Subclass Receptor) ```

Answer 25

A G-protein (bound to GTP) assists in transmitting the signal. G-protein activates an effector protein (usually an enzyme).

Question 26

Ras G protein is _____, binds to _____ in its active form and _____ in its inactive form.

Answer 26

monomeric GTP GDP

Question 27

Trimeric G protein has three subunits: _____, _____, and _____. It binds to _____ in its active form and _____ in its inactive form.

Answer 27

``` alpha beta gamma GTP GDP ```

Question 28

Effector Protein

Answer 28

The enzyme (usually) activated by G-protein in GPCRs.

Question 29

Once activated, a effector protein produces a _____ which generates the _____ to the original signal.

Answer 29

second messenger | cellular response

Question 30

One common effector protein is _____ which produces _____ as a second messenger.

Answer 30

adenylyl cyclase | cAMP

Question 31

cAMP binds to _____ and activates it.

Answer 31

Protein Kinase A

Question 32

Another common effector protein is _____.

Answer 32

Phospholipase C

Question 33

_____ is acted on by effector protein Phospholipase C.

Answer 33

PIP(sub2)

Question 34

Phospholipase C produces _____ plus _____.

Answer 34

IP(sub3) -Inositol Tris Posphate DAG -Diacyl Glycerol

Question 35

PIP(sub2) and IP(sub3) act as _____.

Answer 35

second messengers

Question 36

cAMP Signaling Pathway

Answer 36

1. Ligand binds to GPCR 2. GDP phosphorylated to GTP by protein kinase 3. GTP binds to Adenylyl Cyclase, producing cAMP. 4. cAMP binds to and activates Protein Kinase A (PKA), producing a response protein.

Question 37

Ca2+ serves widely as a _____.

Answer 37

second messenger

Question 38

_____ levels of Ca2+ are normally low.

Answer 38

Intracellular

Question 39

_____ levels of Ca2_ are normally high.

Answer 39

Extracellular

Question 40

The _____ has receptor proteins that act as ion channels to release Ca2+. These receptor proteins bind most commonly to IP(sub3).

Answer 40

endoplasmic reticulum

Question 41

Most signaling molecules exist in such _____ concentration, diffusion across the cytoplasm requires _____.

Answer 41

low | amplification

Question 42

A single cell surface receptor can stimulate a _____ to amplify the signal.

Answer 42

cascade of protein kinases

Question 43

Different receptors can produce _____ second messengers.

Answer 43

the same

Question 44

The hormones _____ and _____ can both stimulate liver cells to mobilize glucose.

Answer 44

glucagon | epinephrine

Question 45

Single signaling molecules can have _____ effects in different cells.

Answer 45

different

Question 46

Multiple forms of the same receptor are called _____ or _____.

Answer 46

subtypes | isoforms

Question 47

The receptor for epinephrine has _____ isoforms, each encoded by different _____.

Answer 47

nine | genes

Question 48

Different isoforms activate different _____, leading to different _____.

Answer 48

G proteins | signal transduction pathways

Question 49

A steroid hormone receptor has three functional domains: _____, _____, and _____.

Answer 49

hormone-binding domain DNA binding domain domain that interacts with co-activators to affect gene expression

Question 50

Intracellular receptors can act as _____ and _____.

Answer 50

gene regulators | enzymes

Question 51

The target cell's response to a _____ can vary enormously.

Answer 51

lipid-soluble cell signal

Question 52

Estrogen has different effects in _____ tissue than _____ tissue.

Answer 52

uterine | mammary

Question 53

Receptor tyrosine kinases are _____ receptors.

Answer 53

membrane

Question 54

Receptor tyrosine kinases, when bound by a ligand, are activated by _____ and then _____.

Answer 54

dimerization | autophosphorylation

Question 55

Receptor tyrosine kinases, when activated, add a _____ to a _____.

Answer 55

phosphate | response protein

Question 56

Mitogen-activated protein (MAP) kinases stimulate _____.

Answer 56

cell division.

Question 57

Mitogen-activated protein (MAP) kinases are activated by a _____.

Answer 57

kinase cascade | phosphorylate each other in succession

Question 58

Mitogen-activated protein (MAP) kinases _____ the signal.

Answer 58

amplify

Question 59

Ras proteins are small _____.

Answer 59

GTP-binding proteins

Question 60

Ras proteins link the _____ and the _____.

Answer 60

RTK | MAP kinase cascade

Question 61

Ras proteins are _____ in many human tumors.

Answer 61

mutated.

Question 62

Ras proteins are indicated to play a centrol role in linking _____ to their cellular response.

Answer 62

growth factor receptors

Question 63

Ras can _____.

Answer 63

regulate itself.

Question 64

Scaffold proteins are thought to organize the components of a _____ into a single _____.

Answer 64

kinase cascade | protein complex

Question 65

Scaffold proteins bind to each individual _____ such that they are spatially organized for optimal function.

Answer 65

kinase

Question 66

Scaffold proteins benefit in _____.

Answer 66

efficiency

Question 67

Scaffold proteins are disadvantaged in that they reduce the _____.

Answer 67

amplification effect

Question 68

Cells contain an array of _____ on the cell surface.

Answer 68

marker proteins

Question 69

Glycolipids

Answer 69

Tissue-specific cell surface markers.

Question 70

Major histocompatibility complex (MHC) proteins

Answer 70

Identify self versus non-self cells.