Phys Ch5

Type of cell-to-cell communication which is common in smooth and cardiac muscle

Substance that has a signaling function

Molec that binds to a biomolec

Chemical that signals & triggers a cellular response by binding to receptor on the cell

Chemical which binds to cell receptor, basically blocking it from other chemicals binding, resulting in no cellular signal/response

Chemical that serves to signal nearby cell (ex: histamine responsible for inflammation response)

Chemical that signals the same cell that secreted it (source cell & target cell are the same)

Chem msgnr produced by neurons & released into the ECF of synaptic cleft (short distance)

Chem msgnr produced by endocrine cells & secreted into blood via interstitial fluid

Chem msngr produced by neurons and secreted into blood via interstitial fluid (ex: antidiuretic hormone (ADH), oxytocin)

Chem msgnr which cannot easily pass cell membranes so may need pump or channel; often on cell mem

General action of lipophobic ligands (2)

Chem msngr which easily crosses cell mem; receptor located w/in cell

General action of lipophilic ligands

Ligands move to their target cells by:

In blood-borne transport, lipophobic ligands ________ and lipophilic ligands ________

Messenger Half-life

How a chemical signal is translated into a cell action:
Msngr binds to receptor
Binding results in cell response

Strength of binding

Location of binding:
Lipophobic ligands:
Lipophilic ligands:

When receptor number decreases on target cell; may result from excess msngr
Results in lower sensitivity to msngr b/c of tolerance

When receptor number increases on target cell, causing increase of sensitivity to msngr; may result from too little msngr

2 mechanisms of signal transduction

3 types membrane-bound receptors

What kind of ligands are involved in intracellular-mediated response & why

How does cell respond to a lipophilic ligand coming in and binding to a receptor?

How do the membrane-bound receptors of the target cell respond to ligand binding? (2 general ways)

Type of receptor in which the receptor and channel are the same protein; binding of ligand causes channel to open or close; chg in transport of ions thru channel causes response
(Binding on outside causes chg on inside)

Type of receptor in which the receptor and enzyme are the same protein; the ligand binding activates the enzyme which causes response
(enzyme is "w/in" protein)
(picture cell mem protein w/ receptor end on outside, enzyme end on opposite side inside gets chgd at the "active site")

Type of receptor which involves a regulatory protein that links a receptor to other mem proteins, including ion channels and amplifier enzymes

Why are G protein-linked channels called slow ligand-gated channels?

Type of receptor which is activated by binding of ligand, and then goes on to activate a channel protein, causing target response b/c of chg in transport of ions thru channel (this chgs cell mem permeability b/c ions can now enter or not)

How do G proteins-linked receptors activate second messengers?

cAMP is a type of _____ that signals that the cell is out of energy

A second msngr is a type of ____