Cell signaling part 1

Question 1

the transmitting cell is usually a

Answer 1

neuron or endocrine cell

Question 2

the signal/message is usually a

Answer 2

hormone or neurotransmitter

Question 3

the target cell undergoes - when the signal is near

Answer 3

it receives the signal on its receptor and this activates a second messenger (cyclic AMP or ions) which then reaches the effector

Question 4

signal transduction

Answer 4

process in which an external signal is converted into a specific cellular response

Question 5

what types of communication occur if the signal is membrane bound

Answer 5

contact dependent signaling and electric synapse

Question 6

what types of communications occur if the signal is a secreted molecule

Answer 6

endocrine, paracrine, chemical synapse, autocrine

Question 7

contact dependent signaling

Answer 7

is a very short range communication. Delta and Notch receptor is important for embryonic development

Question 8

Gap junctions

Answer 8

are used for electrical synapses and they are bidirectional. It is a very rapid transmission of action potential from neuron to neuron

Question 9

chemical synapses

Answer 9

can be a type of paracrine communication, an action potential results in release of neurotransmitter signal from presynaptic cell

Question 10

cell signaling can be generalized in 4 steps

Answer 10

reception, transduction, response, switch off

Question 11

reception involves

Answer 11

the binding of a ligand and the change in conformation to produce a biological effect

Question 12

transduction involves

Answer 12

relay signal onwards, amplify the signal, integrate different signals, distribute signal on several effectors

Question 13

Ach given to heart, salivary gland, skeletal muscle cell results in what response

Answer 13

~slower heart rate
~increase saliva
~muscle contraction

Question 14

the ‘switch off’ involves

Answer 14

remove the ligand, remove/switch off the receptor, Act on molecular switches, and remove the second messenger

Question 15

how do you remove a neurotransmitter signal

Answer 15

reuptake by presynaptic cell, uptake by neighboring glial cells (GABA), enzymatic degradation

Question 16

how do you remove the receptor?

Answer 16

by internalization, or inactivation of receptor

Question 17

steroid and thyroid hormones bind to

Answer 17

intracellular receptors, as they are liposoluble/hydrophobic signals they cross the plasma membrane and bind to intracellular receptors located in the cytoplasm or nucleus

Question 18

steroid and thyroid signaling is used for

Answer 18

~replacement therapy
~anti-inflammatory (cortisone)
~hormonal therapy of cancer
~substance abuse

Question 19

intracellular receptors act as

Answer 19

transcription factors , like cortisol and testosterone in the cytoplasm and thyroxine in the nucleus

Question 20

intracellular receptors have 3 domains

Answer 20

~ligand binding domain
~DNA binding domain
~transcription activating domain