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.
Question 4
Question
Binding of a ligand to its receptor of the cell membrane can directly cause:
Answer
Opening of an ion channel.
Activation of a carrier protein.
Endocytosis.
None of the above.
Question 5
Question
Glucose moves _____ its concentration gradient from the intestinal lumen into cells, and then ________ its gradient across the basal lamina.
Answer
up, up
up, down
down, up
down, down
Question 6
Question
Decreasing the proton concentration in the mitochondrial intermembrane space would __________ the production of ATP, via ATP synthase, an ______________________.
Answer
increase, F-type pump
Increase, ABC transporter
Decrease, F-type pump
Decrease, ABC transporter
Question 7
Question
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.
Answer
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.
Question 8
Question
In which answer have the molecule been correctly arranged by their ability to freely diffuse across the plasma membrane, from least to most permeable.
Answer
Ethanol, K+, nitrous oxide (NO), glucose.
Sodium ions, glucose, oxygen, water.
Protons , glucose, ethanol, carbon dioxide.
Water, Cl-, glucose, nitrous oxide (NO).
Question 9
Question
Which of the following are true about voltage-gated ion channels?
Answer
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.
Question 10
Question
__________________ ATPases are responsible for pumping protons ________ their electrochemical gradient into vesicles. The proton gradient is then used to transport neurotransmitter __________ the vesicles.