THE CELL
STRUCTURE AND FUNCTION OF THE CELL
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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The use of a protein pump (ions like Na+, K+, H+, etc.) is an example of ____ because ____
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exocytosis; ions are moved out of the cell
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active transport; ATP is required
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facilitated diffusion; a protein is needed for transport
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endocytosis; ions are moved into the cell
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Explanation:
Detailed explanation-1: -The sodium-potassium pump carries out a form of active transport-that is, its pumping of ions against their gradients requires the addition of energy from an outside source.
Detailed explanation-2: -Protein pumps are transmembrane proteins, which are involved in the active transport of ions across the membrane against the concentration gradient.
Detailed explanation-3: -The Na⁺/K⁺-ATPase enzyme is active (i.e. it uses energy from ATP). For every ATP molecule that the pump uses, three sodium ions are exported and two potassium ions are imported. Thus, there is a net export of a single positive charge per pump cycle.
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