How will a small decrease in extracellular sodium ion concentrations affect sodium transport across the plasma membrane.
Sodium ions will continue to move via simple diffusion into the cell.
Sodium ions will still flow into the cell, but at a slightly slower rate.
The direction of sodium ion movement will be reversed.
Sodium transporters will require energy to pump the ions against their gradient.
None of these answers is correct.
Which of the following is true about carbon dioxide transport?
It diffuses freely across membranes.
It require a carrier protein to diffuse into cells.
Carbon dioxide and oxygen are transported in/out of the cell through an anti-porter.
It is converted to bicarbonate in erythrocytes and transported from the body to the lungs.
None of the above
Based on the patch clamp recording shown here, which of the following is true.
The channel being recorded spends more time open than it does closed.
The flow of ions through the channel is indicated by the increase in current.
Sodium flows through the channel more often than calcium.
The channel allows both negative and positive ions to flow through.
None of these is true.
Binding of a ligand to its receptor of the cell membrane can directly cause:
Opening of an ion channel.
Activation of a carrier protein.
Endocytosis.
None of the above.
Glucose moves _____ its concentration gradient from the intestinal lumen into cells, and then ________ its gradient across the basal lamina.
up, up
up, down
down, up
down, down
Decreasing the proton concentration in the mitochondrial intermembrane space would __________ the production of ATP, via ATP synthase, an ______________________.
increase, F-type pump
Increase, ABC transporter
Decrease, F-type pump
Decrease, ABC transporter
Caffeine is an agonist for the ryanodine receptor. What effect would an increase in intracellular caffeine have on muscle cells? Why? There may be multiple correct answers.
Muscle cells would contract more often because calcium would be released more often from the SR.
Muscles would become more stiff because calcium would be removed from the cell more quickly.
Muscle contraction would be stronger because more calcium would be released into the cytoplasm.
None of these.
In which answer have the molecule been correctly arranged by their ability to freely diffuse across the plasma membrane, from least to most permeable.
Ethanol, K+, nitrous oxide (NO), glucose.
Sodium ions, glucose, oxygen, water.
Protons , glucose, ethanol, carbon dioxide.
Water, Cl-, glucose, nitrous oxide (NO).
Which of the following are true about voltage-gated ion channels?
Size of pore and ability of channel to strip ion of water molecules determines which ions are allowed through.
They only participate in passive transport.
Most of them are opened by depolarization.
Some of them contain an inactivating loop.
__________________ ATPases are responsible for pumping protons ________ their electrochemical gradient into vesicles. The proton gradient is then used to transport neurotransmitter __________ the vesicles.
V-type, up, into
F-type, up, out of
V-type, down, into
F-type, up, into
ABC, up, out of
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