교과서 질문
Epithelial cells of the kidneys have pumps that drive the transcellular transport of sodium ions.
The movement of sodium ions drives the transcellular transport of water. Explain why water follows sodium. (Connects to Chapter 3)
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2. Cell Chemistry & Cell Components
Introduction to Membrane Transport
Multiple Choice
Why are ion channels necessary for the transport of ions into or out of a cell?
A
Ion channels are responsible for the synthesis of ions within the cell.
B
Ion channels allow ions to move across the cell membrane down their concentration gradient.
C
Ion channels actively transport ions against their concentration gradient using ATP.
D
Ion channels provide a hydrophobic pathway for ions to pass through the lipid bilayer.
검증된 단계별 안내1
Understand the structure of the cell membrane: The cell membrane is primarily composed of a lipid bilayer, which is hydrophobic and acts as a barrier to most ions, preventing them from freely passing through.
Recognize the role of ion channels: Ion channels are specialized proteins embedded in the cell membrane that provide a hydrophilic pathway for ions to pass through, allowing them to move across the membrane.
Identify the mechanism of ion movement: Ion channels facilitate the passive transport of ions, meaning ions move down their concentration gradient without the use of energy (ATP). This is crucial for maintaining cellular homeostasis.
Distinguish between passive and active transport: Unlike ion pumps, which actively transport ions against their concentration gradient using ATP, ion channels do not require energy and rely on the natural movement of ions from areas of high concentration to low concentration.
Clarify the misconception: Ion channels do not synthesize ions nor provide a hydrophobic pathway; instead, they allow ions to move across the cell membrane by providing a hydrophilic route, essential for various physiological processes.
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