Active transport differs from facilitated diffusion in that active transport
- A. does not require a carrier protein
- B. requires ATP and can move a substance against its concentration gradient
- C. occurs only in plant cells
- D. moves only water molecules
Explanation
Both use carrier proteins, but facilitated diffusion is passive and can only run down a gradient, whereas active transport spends ATP and can therefore concentrate a substance on one side of the membrane. This is how glucose is fully reabsorbed in the kidney tubule and how root hair cells take in mineral ions from very dilute soil water. Cells performing much active transport are rich in mitochondria.
Related questions
The fluid mosaic model describes the plasma membrane as
The statement that all cells arise from pre-existing cells was added to the cell theory by
The large central vacuole of a mature plant cell is bounded by a membrane called the
Which structure is normally absent from the cells of higher plants?
Plasmodesmata are