Physiology: Signal transduction

Question 1

A ligand/transmitter/chemical binds to its specific receptor and it will initiate a cascade of events that will ultimately result in the response that the specific cell should manifest

Answer 1

SIGNAL TRANSDUCTION

Question 2

What type of signal transduction is Cholinergic nicotinic receptors under?

Answer 2

Ligand – gated ion channels

Question 3

What type of signal transduction is α and β adrenoceptors under?

Answer 3

G protein - coupled receptors

Question 4

What type of signal transduction is insulin receptors under?

Answer 4

Enzyme - linked receptors

Question 5

What type of signal transduction is steroid receptors under?

Answer 5

Intracellular receptors

Question 6

Receptor for caffeine in Ligand gated ion channel

Answer 6

Ryanodine receptor

Question 7

What ion channel is opened by Ryanodine receptor?

Answer 7

calcium channel

Question 8

They are opened or closed by hormones, second messengers, or neurotransmitters.

Answer 8

Ligand-gated channels

Question 9

What enzyme does caffeine inhibit in G protein coupled receptor

Answer 9

Phosphodiesterase

Question 10

opened or closed by changes in membrane potential.

Answer 10

Voltage-gated channels

Question 11

mediate direct and rapid synaptic signaling between electrically excitable cells

Answer 11

Ligand-gated channels

Question 12

regulate the activity of other proteins, such as enzymes and ion channels

Answer 12

GPCR

Question 13

G protein sub units

Answer 13

α, β, and γ subunits

Question 14

either function as enzymes or are associated with and regulate enzymes

Answer 14

Enzyme-linked receptors

Question 15

T/F, Most enzyme-linked receptors are protein kinases or are associated with protein kinases,

Answer 15

True

Question 16

small hydrophobic molecules, that have a long biological half-life (hours to days), diffuse across the plasma membrane, and bind to nuclear receptors or to cytoplasmic receptors that, once bound to their ligand, translocate to the nucleus

Answer 16

Nuclear receptors

Question 17

Steroid hormones, thyroid hormones, retinoids, and vitamin D bind to what type of receptor

Answer 17

Nuclear receptors

Question 18

This class of receptors transduces a chemical signal into an electrical signal, which elicits a response.

Answer 18

Ligand-gated channels

Question 19

Activation of G protein stimulates ___ enzyme

Answer 19

Adenylate cyclase

Question 20

Adenylate cyclase increases that level of___

Answer 20

cAMP

Question 21

Increase level of cAMP activates what enzyme?

Answer 21

Protein Kinase A

Question 22

Enzyme that breaks down cAMP

Answer 22

Phosphodiesterase enzymes

Question 23

Phosphodiesterases facilitate the breakdown of cAMP and cGMP to

Answer 23

AMP and GMP,

Question 24

Another way to degrade cAMP or cGMP is

Answer 24

dephosphorylation of effectors by protein phosphatases.

Question 25

Effect of caffeine activation of cAMP and PKA

Answer 25

stimulate the release of calcium from the ER/SR Therefore, having more cardiac contraction and eventual palpitations.

Question 26

promote the translocation of the glucose transporters from the cytoplasm to the cell membrane.

Answer 26

PI-3K pathway

Question 27

glucose in the circulation can get into the cell by way of

Answer 27

glucose transporters.

Question 28

General mechanism of Steroid when bound to DNA receptor

Answer 28

anti-inflammatory proteins are increased while pro-inflammatory proteins are inhibited

Question 29

anti-inflammatory proteins that have been induced by steroid

Answer 29

Lipocortin-1 IL-10 IL1- receptor

Question 30

inflammatory proteins are inhibited that have been inhibited by steroids

Answer 30

o ICAM-1 o IL-4 o IL- 5 o IL-6 o IL-13 o TNF- alpha o VCAM-1

Question 31

released during penile erection and binds to its guanylyl cyclase receptor (similar to adenylyl cyclase) which will increases the formation of cGMP.

Answer 31

Nitric oxide

Question 32

stimulate smooth (corpora cavernosa) muscle relaxation in penile erection

Answer 32

cGMP

Question 33

an oral drug, inhibits phosphodiesterase enzyme.

Answer 33

Sildenafil (blue pill)

Question 34

enzyme that releases arachidonic acid (AA)

Answer 34

Phospholipase A2

Question 35

Three Pathways of A.A

Answer 35

Cyclooxygenase (COX) 5-Lipoxygenase Epoxygenase (Cytochrome P 450):

Question 36

facilitates metabolism of AA to prostaglandin, thromboxane and prostacyclin

Answer 36

Cyclooxygenase (COX)

Question 37

initiates conversion of AA to leukotrienes

Answer 37

5-Lipoxygenase

Question 38

enzyme that facilitates generation of hydroxyeicosatetraenoic acid (HETE) and cis-epoxyeicosatrienoic acid (EET)

Answer 38

Epoxygenase (Cytochrome P 450):

Question 39

mediate platelet aggregation, causes airway constriction, and induce inflammation

Answer 39

Prostaglandin

Question 40

induces platelet aggregation, constrict blood vessels

Answer 40

Thromboxanes

Question 41

inhibits platelet aggregation, dilates blood vessels

Answer 41

Prostacyclins

Question 42

participates in allergic and inflammatory responses

Answer 42

Leukotrienes

Question 43

increases release of Ca++ from ER and stimulate cell proliferation

Answer 43

HETE & EET

Question 44

Explain the THE cAMP and Ca Pathway

Answer 44

 Signal Molecule (e.g. epinephrine) binds to a cell surface receptor protein it activates a G protein inside of the cell.  The G protein then stimulates adenylyl cyclase produce large amounts of cAMP within the cell.  cAMP binds to and activates a target protein such as α-kinase which adds phosphates to specific proteins in the cell.  The effect of this phosphorylation depends on the identity of the cell and the proteins that are phosphorylated  Calcium Ions also serve as second messengers. In response to a signal molecule from other cells. The cell surface receptor proteins activates a G protein which in turn activates enzyme Phospholipase C.  Phospholipase C catalyzes the production of Inositol triphosphate diffuses through the cytoplasm to the ER.  The Inositol triphosphate binds to and opens Ca channels allowing Ca ions to flow from the ER into the cytoplasm.  The Ca ions trigger protein sensitive to Ca to initiate a variety of activities.

Question 45

catalyzes the production of Inositol

Answer 45

Phospholipase C

Question 46

T/F, Steroid Hormone are not water soluble

Answer 46

true

Question 47

DNA regions where steroid hormones bind

Answer 47

hormone response elements.

Question 48

How does steroid works to reduce inflammation?

Answer 48

It binds to certain parts of the DNA which effect on the level of transcription of that site. The mRNA is produced which then codes for the synthesis of specific protein.

Question 49

What is attached to the G protein subunit intracellularly prior to ligand binding

Answer 49

guanosine diphoshate(GDP)

Question 50

What forms in the alpha subunit after ligand binding to G protein receptor

Answer 50

guanosine triphosphate(GTP)

Question 51

photo receptors cells in the retina of the eye motor

Answer 51

Rod cells

Question 52

photo receptor protein found in the outer segment of the rods are stacks of membranous disks and embedded in the disk membrane is called

Answer 52

Rhodopsin

Question 53

light sensitive molecule found in the rhodopsin is called

Answer 53

retinal

Question 54

Found in the outer membrane of the rod cGMP-gated

Answer 54

Na ion channels.

Question 55

What happense when a photon of light strikes rhodopsin

Answer 55

retinal isomerization initiates rhodopsin activation

Question 56

Active rhodopsin binds \_\_\_, a trimeric G protein.

Answer 56

transducin

Question 57

aggressive breast cancer are driven by a transmembrane receptor protein known

Answer 57

HER2

Question 58

How HER2 causes breast cancer

Answer 58

over expression is a trememdous increase in receptor mediated intracellular signaling

Question 59

Ligands of Ligand gated ion channel

Answer 59

Question 60

Ligand of GPCR

Answer 60

Question 61

Ligands for Enzyme link receptor

Answer 61

Question 62

Ligands for nuclear receptor

Answer 62