1. Diffusion is the movement of molecules from an area of higher concentration to an area of lower concentration.
2. Osmosis is the diffusion of water across a selectively permeable membrane.
3. Molecules move through the cell membrane via diffusion, osmosis, or facilitated diffusion (with carrier proteins), depending on their size, charge, and concentration gradient.
4. The solute is the substance dissolved in a solvent (e.g., salt in water).
5. a. Sugar dissolves in water → diffusion
b. Ink spreads in water → diffusion
c. Water moves into a cell → osmosis
d. Oxygen enters blood cells → diffusion
e. Water leaves a cell → osmosis
6. a. Diffusion — molecules move from high to low concentration
b. Osmosis — water moves across a membrane toward higher solute concentration
c. Active transport — requires energy to move substances against concentration gradient
d. Facilitated diffusion — uses carrier proteins to move substances down concentration gradient without energy
7. a. True — diffusion occurs until equilibrium is reached
b. False — osmosis specifically involves water movement across a membrane
c. True — active transport requires energy (ATP)
d. False — diffusion does not require energy; it is passive
e. True — osmosis is a type of diffusion involving water
f. False — facilitated diffusion does not require energy; it uses proteins but follows concentration gradient
Parent Tip: Review the logic above to help your child master the concept of cell processes worksheet.
