Hormones and Receptors

Question 1

Hormones producing organs and hormones in the hypothalamus:

Answer 1

dopamine, ADH (vasopressin), oxytocin (releasing hormones)

Question 2

Which organ is the control center of the endocrine system?

Answer 2

hypothalamus

Question 3

Which organ is the master gland of the ES?

Answer 3

pituitary

Question 4

Where does the hypothalamus send signals to?

Answer 4

pituitary

Question 5

Events that happen inside the cell and don’t require immediate gene expression

Answer 5

nongenomic effects

Question 6

what are 2 nongenomic effects:

Answer 6

altered metabolism

altered shape or movement

Question 7

Which effect results in altered gene expression?

Answer 7

genomic effects

Question 8

What type of proteins are cell-surface receptors?

Answer 8

transmembrane spanning proteins

Question 9

Extracellular signaling molecules act at very (high/low) concentrations

Answer 9

low

Question 10

extracellular signaling molecules’ cognate receptors bind with (high/low) affinity at low concentrations

Answer 10

high

Question 11

How is the specificity of the signaling molecule (hormone) action regualted?

Answer 11

presence of the receptor to which the molecule (hormone) binds

Question 12

nomenclature of extracellular signaling molecules (8)

Answer 12

peptide hormones, steroid hormones, growth factors, mitogens, cytokines, neurotransmitters and chemokines

Question 13

Hormone secretion:

Answer 13

external signal/condition triggers HYPOTHALAMUS to release RELEASING HORMONE which triggers the ANT. PIT. to release a TROPIC HORMONE which targets ENDOCRINE gland which produces HORMONE

Question 14

As hormone levels increase they can FEEDBACK to the levels of the ____ and _____.

Answer 14

hypothalamus

pituitary

Question 15

What happens if the long NEGATIVE FEEDBACK LOOPS stops working?

Answer 15

continuous production of hormones

Question 16

Where do the short-loop negative feedback loops feedback from and to? What does it inhibt?

Answer 16

from TROPIC HORMONE
to HYPOTHALAMUS
inhibits releasing hormone

Question 17

Hormone signaling is a type of _____ communcation.

Answer 17

cell-cell

Question 18

How is the type of cell-cell communication defined?

Answer 18

• where signal ORIGINATES
• where the is RELEASED into
• where target(s) is/are located
• types of cells involved in signaling

Question 19

what are the 4 mechanisms of ligand presentation to target cells

Answer 19

• contact-dependent (juxtacrine)
• paracrine
• synaptic
• endocrine

Question 20

mechanism when one cell presents ligand to another cell nearby that has the receptor

Answer 20

contact-dependent (juxtacrine)

Question 21

mechanism in which signaling cell produces a factor that stays within the local environment

Answer 21

paracrine

Question 22

mechanism that is a form of paracrine signaling involving chemical synapses or juxtacrine involving electrical synapses
(neuron, NT)

Answer 22

synaptic

Question 23

mechanism where endocrine cell produces hormone that enter bloodstream, circulates throughout the body, and initiates cellular response where it finds target cell with receptor

Answer 23

endocrine

Question 24

What type of communication is involved in gap junctions?

Answer 24

cell-cell comm.

(small molecules can move through gap junctions between 2 adjacent cells

Question 25

What type of signaling is stimulated by binding of hormone and produces an extracellular signaling molecule which feedbacks on cell that produced it to stimulate it.

Answer 25

autocrine signaling

Question 26

Plasma membrane receptor systems: ligands (3)

Answer 26

- protein and peptide hormones - catecholamines (epinephrine-adrenaline; norepinephrine- dopamine) - Eicosanoids (derived from arachidonic acid or polyunsaturated fatty acids. e.g. prostaglandins)

Question 27

T/F: receptors are generally designated by the ligand they bind or their function

Answer 27

true

Question 28

receptor that has at least 7 transmembrane spanning domains and an extracellular ligand binding site

Answer 28

G-protein coupled receptor

Question 29

What occurs following the binding of a hormone to its plasma membrane associated receptor?

Answer 29

series of intracellular events occur that lead to the ultimate changes in cell FUNCTION

Question 30

What stimulates the G-coupled receptor in the formation of cAMP?

Answer 30

epinephrine

Question 31

Activation of adenylyl cylase results in formation of ___ from ____.

Answer 31

cAMP from ATP

Question 32

What does cAMP bind to and activate?

Answer 32

PKA

Question 33

What happens after cAMP activates PKA?

Answer 33

activation of phosphorylase-alpha and breakdown of glycogen to glucose-1-phosphate

Question 34

What are the most common intracellular second messengers?

Answer 34

cAMP** cGMP DAG IP3

Question 35

What are the 3 types of second messengers?

Answer 35

- hydrophilic - hydrophobic - gases

Question 36

Where are hydrophilic 2nd messengers located and give examples of some.

Answer 36

cytoplasm (water-soluble) | cAMP, cGMP, IP3, Ca+2

Question 37

Where are hydrophobic 2nd messengers located and give examples of some.

Answer 37

membrane associated (water insoluble) -diffuse from PM and bind to membrane associated effector proteins involved in variety of signaling cascades -DAG and phosphoinositols

Question 38

Where do 2nd messenger gases diffuse through?

Answer 38

both cytosol and across CM | NO, CO, HS

Question 39

syndrome caused by the mutation in GNAS which results in a G-protein which is ALWAYS ON leading to overproduction of hormones resulting in abnormal bone growth, unusually skin pigmentation, and endocrine problems.

Answer 39

McCune-Albright syndrome

Question 40

GNAS codes for the _____ which activates adenylate cycle

Answer 40

G-protein

Question 41

Where is GNAS expressed?

Answer 41

endocrine glands and bone

Question 42

Are somatic mutations inheritable?

Answer 42

no

Question 43

Are mutations in G-proteins (inherited?

Answer 43

no - somatic

Question 44

when some cells express normal version of GNAS and some express mutated version:

Answer 44

mosaicism

Question 45

What are GTP-binding proteins inactivated by?

Answer 45

bacterial toxins

Question 46

What is the most important class of intracellular signaling hormones?

Answer 46

steroid hormones

Question 47

When a cell with Notch is cleaved and binds to another delta cell (juxtacrine signaling) and leads to transcription of notch target genes

Answer 47

signaling mediated through regulated PROTEOLYSIS

Question 48

Cell signaling pathways __ initial signal many fold to achieve cellular response.

Answer 48

amplify

Question 49

Enzyme linked cell surface receptors have ______ and _______ domains that can take on various configurations and have enzyme/kinase associated activity, respectively.

Answer 49

Extracellular | Intracellular