Part 1: Aspects of signal transduction

Question 1

Juxtacrine mode of transduction

Answer 1

direct physical contact

Question 2

Juxtacrine sender cells

Answer 2

cells in most body tissues (cardiac muscle, skin, retinal neurons)

Question 3

Juxtacrine Target cells

Answer 3

cells adjacent to sender cells

Question 4

Juxtacrine types

Answer 4

Surface protein/receptor interaction–> binding of membrane bound surface protein of sender to target

Gap junction-> cytoplasm to cytoplasm exchange of intracellular ions/molecules thru tubular protein structures

Question 5

Connexon

Answer 5

1 connexon = 6 connexins
each connexin has 4 transmembrane domains, 2 extracellular loops
-loops aid in connexon-connexon docking for gap junctions

Question 6

Endocrine mode of transduction

Answer 6

release of secreted molecules into bloodstream

Question 7

endo sender cells

Answer 7

specialized in glandular tissues

Question 8

endo target cells

Answer 8

cells in various tissues that express specific receptors

Question 9

endo signal molecules

Answer 9

hormones

Question 10

endo range

Answer 10

long distance

Question 11

endo concentraion

Answer 11

very low (10^-12-10^-9M)

Question 12

endo receptors

Answer 12

very high affinity

Question 13

endo on/off response

Answer 13

slow (minutes to hours)

Question 14

Paracrine mode of transduction

Answer 14

release and diffusion of secreted molecules into extracellular space

Question 15

para sender cells

Answer 15

cells in various tissues throughout the body

Question 16

para target cells

Answer 16

neighboring cells

Question 17

para signal molecules

Answer 17

local mediators (growth factors, cytokines)

Question 18

para range

Answer 18

short distance

Question 19

para concentration

Answer 19

low to high (10^-9-10^-6M)

Question 20

para on/off response

Answer 20

rapid

Question 21

synaptic mode of transduction

Answer 21

release and diffusion of secreted molecules into synaptic cleft (extreme form of paracrine signaling)

Question 22

synaptic sender cells

Answer 22

neurons (axon extension)

Question 23

synaptic target cells

Answer 23

neurons, muscle cells

Question 24

synaptic signal molecules

Answer 24

neurotransmitters

Question 25

synaptic range

Answer 25

very short

Question 26

synaptic concentration

Answer 26

very high (10^-6-10^-3M)

Question 27

synaptic on/off response

Answer 27

very rapid (milliseconds)

Question 28

autocrine mode of transduction

Answer 28

release of secreted molecules in vicinity of cells own surface (form of para signaling)

Question 29

autocrine sender cells

Answer 29

cells in various tissues throughout body

Question 30

autocrine target cells

Answer 30

same cell as sender cell

Question 31

autocrine signal molecules

Answer 31

large proteins (growth factors, cytokines)

Question 32

autocrine range

Answer 32

short distance

Question 33

autocrine concentration

Answer 33

low to high (10^-9-10^-6M)

Question 34

autocrine receptors

Answer 34

low to high affinity

Question 35

autocrine on/off response

Answer 35

rapid