Midterm 3 Flashcards
Where in the cell does Ca2+-ATPase mostly exist?
On the SR membrane
Where in the cell is ATPase catalytic domain of Ca2+-ATPase exposed?
Cytosol
Na+/K+-ATPase mainly exists on the ____ membrane, and the ATPase catalytic domain is exposed to the ____
Plasma
Cytosol
When the protein is free from any ion, phosphate, or ATP, its non-binding site is open to _____
Nucleus
Binding of ____ to the protein activates the ATPase
Na+
The ATP hydrolysis results in the covalent binding of the protein to _____
Phosphate
Covalent binding induces a conformational change of the protein. After this change, Na+ is released to _____
Extracellular space
Another ion, ____, binds to the protein. This indices the release of _____ so that the structure of the protein is back to original conformation
K+
Phosphate
Na+/K+-ATPase is a member of _____-type active transporters. This group of transporters includes _____
P
Ca2+-ATPase
What is most appropriate explanation of normal function of the Na+-Glucose symporter?
It transports Na+ only along the electrochemical gradient, but it transports glucose against (uphill) the gradient
Calculate membrane potential
V=62*log(Co/Ci)
K+ concentration inside = 198mM
K+ concentration outside = 15mM
-69.5mV
Which direction does K+ move through the channel?
K+ moves out of the cell
To reduce blood pressure, acetylcholine secreted from ____ stimulates _____ to produce nitric oxide NO
Parasympathetic neuron
Endothelial cell
NO enters the target cell _____ by _____
Smooth muscle
Simple diffusion
In the target cell, NO binds and activates the enzyme _____, which produces _____
Guanylyl cyclase
cGMP
cGMP activates the enzyme ____
PKG
This signaling eventually ____ Ca2+ concentration in the cytosol, resulting in _____ of the target cell
Decrease
Relax
When steroid hormone binds to its receptor, what happens to the receptor?
It dissociates from Hsp90
What does the activated steroid hormone receptor do?
It activates histone acetyltransferase (HAT)
Vitamin C is required for an enzyme called _____
Lysine oxidase
Without vitamin C, collagen protein cannot form stable ____ that causes _____
Triple helix
Scurvy
What is the major component of the basil lamina?
Laminin
Type IV collagen
What is the most appropriate explanation about the structure of GAG?
It is a simple repeat of di-saccharides
What side on the plasma membrane does phospatidylcholine mainly exist?
Outside (extracellular side)
