Channel-linked receptors, voltage, and calcium Flashcards
1
Q
The nicotinic acetylcholine receptor consists of how many subunits?
Each subunit consists of a how many-pass transmembrane protein?
A
5 subunits = 2 alpha, beta, gamma, and delta
Each subunit has a 4-pass transmembrane protein
2
Q
Channel-linked receptors
A
- occur mainly in exictable cells such as muscle or nerve cells
- signaling is fast, like milliseconds
3
Q
depolarization
A
toward +60 mV
“up”
4
Q
hyperpolarization
A
toward -90 mV
“down”
5
Q
Sources of Ca2+
A
- extracellular Ca2+ (very important source)
- mitochondria
- endoplasmic reticulum (and sarcoplasmic reticulum)
6
Q
How much can the Ca2+ levels in the cytosol rise during stimulation?
A
10-100 fold
7
Q
What do Ca2+ binding proteins do to the Ca2+ in the cytosol?
A
buffers it
