This Molecule CANNOT Freely Cross Biological Membranes

question 55

Multiple Choice

This molecule CANNOT freely cross biological membranes:

• A) O₂
• B) CO₂
• C) NH₄⁺
• D) all of the above
• E) none of the above

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Definitions:

Sympathetic Division

Part of the autonomic nervous system that prepares the body for quick action in emergencies; "fight or flight" response.

Parasympathetic Division

Part of the autonomic nervous system responsible for conserving energy and bringing the body to a state of rest by slowing the heart rate, increasing intestinal and glandular activity, and relaxing sphincter muscles.

Central Nervous System

The part of the nervous system consisting of the brain and spinal cord, which interprets sensory information and issues instructions based on past experience and current conditions.

Peripheral Nervous System

The peripheral nervous system is the part of the nervous system that consists of the nerves and ganglia outside of the brain and spinal cord, which connect the central nervous system to limbs and organs.