Active transport process?

Question

Which statement describes an active transport process? I. Sodium ions move from an area of high sodium-ion concentration to an area of low sodium-ion concentration. II. Water molecules move from an area of low solute concentration to an area of high solute concentration. III. Glucose molecules move from an area of low glucose concentration to an area of high glucose concentration.

A. I only

B. II only

C. III only

D. I and II only

E. II and III only

Answer 1

C - those other reactions do not require an outside energy input to effect them.

Answer 2

E.II and III only

Answer 3

lets see, membranes are permeable for water and small salts, or you wouldnt get shrinking and bloating cells in salt- or purewater...glucose has specific carrieres because its pretty big molecule so C

Answer 4

C, III only: this statement requires glucose moving from an area of low concentration to an area of high concentration, which is going against the concentration gradient.

I describes sodium ions moving down a concentration gradient, i.e. passively, while II is describing osmosis; water moving from a region of low solute (i.e. high water concentration) to a region of high solute (or less concentrated water).