Based on Figure 7.18, which of these experimental treatments would increase the rate of sucrose transport into a plant cell?a. decreasing extracellular sucrose concentrationb. decreasing extracellular pHc. decreasing cytoplasmic pHd. adding a substance that makes the membrane more permeable to hydrogen ions

Which of the following statements about diffusion is true?

Cells A and B are the same size, shape, and temperature, but cell A is metabolically less active than cell B, and cell B is actively converting oxygen to water in cellular respiration. Oxygen will diffuse more rapidly into cell __________ because __________.

Which of these statements describes some aspect of facilitated diffusion?

Which of the following is false in regard to facilitated diffusion?

Draw and label the plasma membrane of a cell that is placed in a solution with concentrations of calcium ions and lactose that are greater than those on the inside of the cell. Use arrows to show the relevant gradients and the activity of the following membrane proteins: (1) a pump that exports protons; (2) a calcium channel; and (3) a lactose carrier.

In terms of structure, how do channel proteins differ from carrier proteins?

Facilitated diffusion across a membrane requires ______________ and moves a solute ______________ its concentration gradient.a. transport proteins . . . up (against)b. transport proteins . . . downc. energy and transport proteins . . . upd. energy and transport proteins . . . down

Cells lining kidney tubules function in the reabsorption of water from urine. In response to chemical signals, they reversibly insert additional aquaporins into their plasma membranes. In which of these situations would your tubule cells have the most aquaporins: after a long run on a hot day, right after a large meal, or after drinking a large bottle of water? Explain.