Although They Are Smaller Than K⁺,Na⁺ Ions Fail to Pass

question 22

Multiple Choice

Although they are smaller than K⁺,Na⁺ ions fail to pass through K⁺ channels because Na⁺

• A)is repulsed by positively charged amino acids at the mouth of the channel.
• B)is too small to interact with oxygen atoms in amino acids on all sides of the channel and therefore does not completely lose its waters of hydration.
• C)is always transported complexes to Cl⁻.
• D)is always transported in a complex with two other Na⁺ ions.
• E)is attracted by other Na⁺ ions,which are at higher concentration outside than inside the cell.

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Definitions:

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Acetylcholine is a neurotransmitter in both the central and peripheral nervous systems, involved in muscle activation, learning, and memory.

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An addictive chemical found in tobacco products that stimulates the brain and enhances feelings of pleasure and arousal.

Monoamine

A category of neurotransmitter that includes serotonin, dopamine, and norepinephrine, which play key roles in regulating mood, arousal, and cognition.