Signaling

Question 1

Primary Signal/Messenger

Answer 1

1. cells rely on them to share information with each other
2. Lock and key (geometrically locked)
   example: Hormone

Question 2

Outline of signaling

Answer 2

1. Reception - Signal received of signal
2. Transduction- Signal is transmitted
3. Response -Signal is received

Question 3

What happens at the end of response?

Answer 3

Change in gene expression

Question 4

Growth factor?

Answer 4

Something that enhances or induces growth

Question 5

What happens in the response?

Answer 5

Activation of cellular response

Question 6

What is a gene?

Answer 6

1. Portion of DNA that codes information that will be active or suppressed depending on the need
2. Genes are highly conserved between species
3. It is not the differences in genes themselves that appear to be responsible for diversity

Question 7

Cell fate determination

Answer 7

undifferentiated cells tale on certain fates (differentiate) during embryogenesis

Question 8

What are the two driving forces in development

Answer 8

Cell fate determination

Morphogenesis

Question 9

Morphogenesis

Answer 9

“Creation of ordered form”-

cell types must be organized properly into tissues, organs

Question 10

Transcription Factors

Answer 10

changes chromatin to allow/block RNA polymerase II access to the gene

helps with gene expression

Question 11

Primary Messenger signals …

Answer 11

stay in between cells

Question 12

Secondary Messengers signals..

Answer 12

always inside the cells

Question 13

Teratogens

Answer 13

Any agent that causes a structural abnormality following fetal exposure during pregnancy

Question 14

Cyclopamine

Answer 14

Teratogen

blocks the action of smoothened

embryos exposed to cyclopamine are similar to those defective in Hedgehod signaling

one eye cow

Question 15

Notch signaling- Lateral Inhibition

Answer 15

Cell express more delta on its surface that its neighbors

notch signaling in the surrounding cells inhibits the expression of genes required for neural differentiation

Question 16

What causes the development of cancer

Answer 16

Protooncogenes

tumor supressors

Question 17

Protooncogenes

Answer 17

Function as positive regulators of cell growth

induce tumors through gain of function

Question 18

Tumor Suppressors

Answer 18

Function as negative regulations of cell growth

loss of function results in tumor growth

Question 19

Receptor-mediated Signal Transduction

Answer 19

1. GPCRs (G Protein coupled receptors)

2. Receptor Tyrosine Kinsases

Question 20

The majority of hormone receptors belong to the family of receptors knows as

Answer 20

G-protein coupled receptors (GPCRs)

Question 21

Peptide Hormones Vs steroid hormones

Answer 21

Peptide Hormones -can’t pass through the membrane

Steroid Hormones- hydrophobic, can pass through the cell membrane

Question 22

Receptor-mediated Signal Transduction via hormones result in

Answer 22

regulating gene transcription

Question 23

G protein

Answer 23

Transmembrane protein that loops around through the membrane 7 times

Question 24

Types of receptor ligands

Answer 24

1. Agonist ( full or partial)

2. Antagonist

Question 25

Ligand is aniother name for

Answer 25

Primary messanger

Question 26

Largest family of proteins in the human genome

Answer 26

G protein coupled receptors | over a 1000 types

Question 27

Andrenergic Receptor

Answer 27

GPCRs Norepinephrine Epinephrine

Question 28

Muscarinic Receptor

Answer 28

GPCRs 1. Bind acetylcholone but are GPCRs 2. Sensitive to muscarine of poisonous mushrooms

Question 29

What are the three subunits of G proteins

Answer 29

alpha beta gamma

Question 30

Which G protein subunit normally bind to GDP?

Answer 30

Alpha subunit

Question 31

What normally binds to the alpha subunit?

Answer 31

GDP

Question 32

What allows the three subunits at the end of the g protein signaling to recombine

Answer 32

alpha subunit hydrolyzes GTP-->GDP

Question 33

IN G protein signaling what are the effector enzymes?

Answer 33

Adenylate Cyclase | Phosopholipase C

Question 34

What happens when GDP is replaced GTP on G protein?

Answer 34

alpha is dissociated from beta and gamma

Question 35

After Primary Messengers (ligands) bind to the membrane which enzymes increase/decrease in activity via G proteins ?

Answer 35

1. Adenylate Cyclase 2. phospholipase C 3. Ca++

Question 36

cAMP | 3

Answer 36

1. cyclicAMP 2. Secondary Messenger 3. Made by Adenylate Cyclase (ATP --> cAMP)

Question 37

What does cAMP activate

Answer 37

Kinases that phosphorylate enzymes that allow physiological response (Ex. move glucose form glycogen)

Question 38

Epinephrine

Answer 38

A Primary messenger | Can stimulate or inhibit the production of cAMP

Question 39

DAG | 3

Answer 39

1. Diacylglycerol 2. Secondary Messenger 3. Made by phospholipase C

Question 40

IP3

Answer 40

1. Inositol 1,4,5-triphosphate 2. Secondary Messenger 3. Made by phospholipase C

Question 41

What does IP3 do?

Answer 41

1. Binds to the ER causing rapid release of Ca++ | 2. Increase in Ca++ causes the activation of protein kinases

Question 42

What does DAG do?

Answer 42

1. Activates membrane-bound protein Kinase C 2. That activates enzymes 3. Leads to Cellular Response

Question 43

What makes the G protein active?

Answer 43

Binding of GTP

Question 44

Properties of secondary messengers

Answer 44

1. small 2. diffusible 3. non protein 4. work inside the cell to trigger a downstream response

Question 45

Ca++

Answer 45

1. Secondary Messenger | 2. Release from ER when IP3 binds to the membrane

Question 46

Once Ca threshold is triggered...

Answer 46

1. Ca++ binds to Calmodulin | 2. Activation of Protein Kinases

Question 47

Protein Kinases

Answer 47

enzymes that phosphorylates making things active

Question 48

Protein Kinase C and their activators

Answer 48

DAG | Ca++

Question 49

Protein Kinase A activators

Answer 49

cAMP

Question 50

Calcium/Calmodulin dependent kinases activators

Answer 50

[Ca++ calmodulin]

Question 51

Receptor Tyrosine Kinases (RTKs)

Answer 51

1. Both receptors and enzymes | 2. Membrane bound proteins

Question 52

Receptor Tyrosine Kinases (RTKs) | 4 major domains

Answer 52

1. extracellular ligand binding domain 2. transmembrane domain 3. intracellular tyrosine kinase domain 4. intracellular regulatory domain

Question 53

Which receptors must dimerize before sending their signal?

Answer 53

Receptor Tyrosine Kinases (RTKs)

Question 54

After tyrosine kinase dimerizes

Answer 54

1. 6 ATPs phosphorylates the dimer | 2. activated relay proteins

Question 55

Receptor Tyrosine Kinase Examples

Answer 55

1. Insulin Receptors | 2. Growth Factor Receptors

Question 56

Tyrosine Kinase Inhibitors are used

Answer 56

In treatment of cancer

Question 57

Cytokine Receptors

Answer 57

Receptors that bind pro or anti inflammatory cytokine and control inflammation

Question 58

Which receptors increases or decreases inflammation ?

Answer 58

Cytokine Receptors

Question 59

Which receptors do not require phosphorylation?

Answer 59

Cytokine Receptors

Question 60

Example of cytokine receptors?

Answer 60

growth hormone prolactin erythropoietin

Question 61

Intracellular or nuclear receptors

Answer 61

1. Not in membranes, in cytosol or in nucleus | 2. Bind to hydrophobic molecules (steroid and thyroid)