Ch 6

Question 1

electrical signals definition

Answer 1

changes in the membrane potential of a cell

Question 2

physiological signals must be ______ or ______

Answer 2

electrical or chemical

Question 3

chemical signals functions

Answer 3

-secreted by cells into ECF
-responsible for most communication within the body

Question 4

four basic methods of cell communication

Answer 4

-gap junctions
-contact-dependent signals
-local communication
-long distance communication

Question 5

gap junction properties

Answer 5

-direct constant and local cell-to-cell communication
-transfer both chemical and electrical signals
-form direct cytoplasmic connections between adjacent cells

Question 6

contact-dependent signals require

Answer 6

interaction between membrane molecules on two cells

Question 7

cell adhesion molecules transfer signals in ______ directions

Answer 7

both

Question 8

autocrine signals act on

Answer 8

the same cell that secreted them

Question 9

paracrine cells are

Answer 9

secreted by one cell and diffuse to adjacent cells

Question 10

forms of local cell-to-cell communication

Answer 10

autocrine and paracrine

Question 11

hormones function for what kind of communication

Answer 11

short and long distance

Question 12

hormones are secreted by

Answer 12

endocrine glands or cells into the blood

Question 13

most rapid type of cell to cell communication

Answer 13

neuro transmitters

Question 14

What are NT

Answer 14

chemicals secreted by neurons that diffuse across a small gap to the target cell. they use electrical signals as well

Question 15

what are neurohormones

Answer 15

chemicals released by neurons into the blood for action at distant targets

Question 16

four categories of membrane receptors

Answer 16

-channel
-enzyme
-GPCR
-Integrin

Question 17

signal transduction converts

Answer 17

one form of signal into a different form

Question 18

transducers convert

Answer 18

extracellular signals into intracellular messages which create a response

Question 19

examples of amplifier enzymes

Answer 19

-adenylyl cyclase
-guanylyl cyclase
-phospholipase C

Question 20

biological signal transduction converts

Answer 20

chemical signals into cellular responses

Question 21

tyrosine is a ______

Answer 21

receptor enzyme

Question 22

GPCR properties

Answer 22

-membrane spanning proteins
-cytoplasmic tail linked to G protein, a three part transducer molecule

Question 23

When G proteins are activated, they ______

Answer 23

-open ion channels in the membrane
-alter enzyme activity on the cytoplasmic side of the membrane

Question 24

adenlylyl cyclase-cAMP pathway

Answer 24

-ligand binds to beta receptor
-beta receptor activates G protein
-G protein turns on adenylyl cyclase
-adenylyl cyclase converts ATP to cAMP
-cAMP activates protein kinase A
-protein kinase A phosphorylates other proteins
-cellular response

Question 25

phospholipase C system pathway

Answer 25

-ligand activates beta receptor
-receptor activates G protein
-G protein activates PL-C
-PL-C converts phospholipids into DAG and IP3
-IP3 diffuses into cytoplasm and causes release of Ca2+ from organelles
-DAG remains in membrane and activates PK-C

Question 26

calcium as an intracellular messenger can alter

Answer 26

-enzyme activity
-gating activity
-gating state
-movement
-exocytosis activity
-embryo development

Question 27

functions of nitric oxide

Answer 27

-activates guanylyl cyclase
-acts as a neurotransmitter and neuro-modulator in brain
-produced by endothelial cells
-affects erectile dysfunction

Question 28

carbon monoxide functions

Answer 28

-also activates guanylyl cyclase and cGMP
-targets smooth muscle and neural tissue

Question 29

hydrogen sulfide functions

Answer 29

-targets cardiovascular system
-garlic is major source of precursors

Question 30

agonist

Answer 30

activates the receptor and still achieves a response

Question 31

antagonist functions by

Answer 31

blocking receptor activity resulting in no cellular response

Question 32

can one ligand trigger multiple receptors

Answer 32

yeeeeeeeeeeeeees

Question 33

forms of down-regulation

Answer 33

-by decreasing the number of receptors
-by decreasing the binding affinity
-one explanation for drug tolerance

Question 34

diseases and drugs target

Answer 34

signal transduction protein

Question 35

cannon’s postulates of homeostatic control systems

Answer 35

1. nervous regulation “preserves the fitness” of the internal environment
2. tonic control
3. antagonistic control
4. one chemical signal can have different effects in different tissues