membrane receptors Flashcards
The cell membrane proteins also work as receptors. What are they?
- Contact signaling receptors
- Chemical Signaling receptors
- G protein receptors
When do contact signaling receptors occur
When cells come into contact with
each other.
-This is important in normal development and immunity.
- For example, the histocompatibility markers used in organ transplants
Different cells can respond differently to the same ligand
True or False
True
What is the regulatory protein molecule called
G protein
A second messenger is generated by the actions of the G protein.
What are the two major second messengers?
cyclic AMP and Ca+2
The result is an amplification of the original signal
Which ions are in large concentration inside the cell
Potassium ions
Ion found in large quantity outside of the cell
sodium ions
large negatively charged ions are found
inside the cell
Due to the preferential “leaking” of potassium ions to the outside, there
is a net
Negative voltage relative to the outside
Stimulation of the membrane results in a sudden change in
polarity called an action potential. This can lead to
Muscle Contraction
Gland Secretion
Nerve Impulse
Why is K+ potentially lethal at high intravenous doses?
It disrupts the Na+ ion channels in the heart muscle making the
initiation of a contraction difficult
Role of sodium/potassium ATP-ase
Maintaning resting potential
