Lecture 2

Question 1

General features of any signalling molecule

Answer 1

must be produced (in advance and stored, or on demand)
must be released (storage optional)
must elicit a response
must have actions terminated

Question 2

Locations of signalling cells

Answer 2

relative locations of signaling and target cell determine distance travelled/stability of messenger molecules

Question 3

Types of intercellular signalling

Answer 3

contact dependent
paracrine
autocrine
endocrine
synaptic
neuronal

Question 4

Contact dependent

Answer 4

also known as juxtacrine signaling

Question 5

Paracrine

Answer 5

signal from one cell is received by neighbouring cells of different types

Question 6

Autocrine

Answer 6

signal from one cell or several cells is received by neighbouring cells of same type

Question 7

Endocrine

Answer 7

signal from one or more cells is received by distant cells via bloodstream

Question 8

Synaptic

Answer 8

signaling between neurons in close proximity; signaling occurs between a presynaptic and postsynaptic neuron

Question 9

Receptors involved in signal transduction

Answer 9

cell-surface receptors

intracellular receptors

Question 10

Cell-surface receptors

Answer 10

hydrophilic = signal molecule (cannot enter cell)

cell membrane, nucleus

Question 11

Intracellular receptors

Answer 11

hydrophobic = signal molecule (can enter cell)

carrier protein, cell membrane, nucleus

Question 12

Simple intracellular signalling pathway

Answer 12

receptor protein - intracellular proteins - target proteins

target proteins = metabolic enzyme, gene regulatory protein, cytoskeletal protein

Question 13

Building blocks of cellular communication

Answer 13

building blocks of all cellular communication processes are inside of the cell
signal molecules, release mechanisms, receptors, response systems, termination mechanisms

Question 14

Structural methods

Answer 14

separation and identification = subcellular fractionation, centrifugation, chemical techniques
tagging = radioisotopes, fluorescent tags
imaging methods = fluorescence, optical, and electron microscopy
molecular technologies = sequencing, blotting

Question 15

Functional methods

Answer 15

cell lines, organ bath studies, animal models = dose-response studies, behavioural experiments
electrophysiology and patch clamping
molecular technologies = genomic manipulation, reporter assays, expression cloning

Question 16

Some signalling molecules

Answer 16

small molecules = gases (NO, CO, H2S), H2O2
amines = histamine, noradrenaline, dopamine, serotonin, acetylcholine
peptides = bradykinin, substance P
polypeptides = insulin, gastrin
steroids= corticosteroids, estrogens, androgens