SCIENCE
CELL BIOLOGY
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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active transport, up the gradient, against the gradient, uses ATP
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active transport, up the gradient, with the gradient, uses ATP
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passive transport, down the gradient, against the gradient, uses ATP
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passive transport, down the gradient, with the gradient, no use of ATP
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Detailed explanation-1: -Active transport is the movement of molecules across a cell membrane from a region of their lower concentration to a region of their higher concentration.
Detailed explanation-2: -The sodium and potassium ions are pumped in opposite directions across the membrane. This pump build a chemical and electrical gradient. These gradients can be used to drive other transport processes. In nerve cells the pump is used to generate gradients of both sodium and potassium ions.
Detailed explanation-3: -During active transport, a protein pump uses energy, in the form of ATP, to move molecules from an area of low concentration to an area of high concentration. An example of active transport is the sodium-potassium pump, which moves sodium ions to the outside of the cell and potassium ions to the inside of the cell.
Detailed explanation-4: -Active transport is the movement of the molecules or ions of a substance from a region of their lower concentration to a region of their higher concentration.
Detailed explanation-5: -Overall, there are more positive charges on the outside of the membrane than on the inside. The concentration of sodium ions is lower inside the cell than in the extracellular fluid, while the reverse is true for potassium ions.