lecture 4 Flashcards
2 categories of cell communication
- local
- long distance (neuronal, endocrine)
3 types of local cell-cell communication
- gap junctions
= direct cytoplasmic connections, adjacent cells - contact-dependent signals
= interaction between membrane molecules on two cells - autocrine/paracrine signals
= act on the same cell that secreted them!!!!
Paracrine signals are secreted by one cell and diffuse to adjacent cells
long distance communication
hormones are secreted by endocrine glands or cells into the blood
Neurotransmitters
only target cells with the receptors for the hormone will respond to the signal
4 classes of chemical signalling molecules
- amino acids
- amines
- peptides or proteins
- steroids
amino acids example
glutamate, glycine, GABA
amines example
dopamine, epinephrine, norepinephrine, seretonin
peptides or proteins example
insulin, glucagon
steroids example
estrogen, testosterone
(derived from cholesterol)
receptor locations
can be intracellular signal receptors or cell membrane receptors
4 categories of membrane receptors
- Receptor-channel
- Receptor-enzyme
- G protein-coupled receptor
- Integrin receptor
Receptor-channel/Ligand-gated channels (describe)
ligand binding opens or closes the channel
Receptor-enzyme/Enzyme-linked receptors (describe)
ligand binding to a receptor-enzyme activates an intracellular enzyme
GPCR (describe)
ligand binding to a G protein coupled receptor opens an ion channel or alters enzyme activity
Integrin receptor
ligand binds to integrin receptors and alters the cytoskeleton
Give an overview of signal transduction
-Signal molecule bind to
-Receptor protein which activates
-Intracellular signal molecules which alter
-Target proteins which create a
-Response