Question

complete the table to compare the three types of passive transport. simple diffusion facilitated diffusion osmosis molecules cross the membrane through the phospholipids molecules cross the membrane through proteins molecules move down their concentration gradient molecules move without using cellular energy

Explanation:

• Simple diffusion: Small non - polar molecules (e.g., oxygen, carbon dioxide) cross the membrane through the phospholipids. They move down their concentration gradient without using cellular energy.
• Facilitated diffusion: Polar or large molecules (e.g., glucose, ions) cross the membrane through proteins (channel or carrier proteins). They also move down their concentration gradient without using cellular energy.
• Osmosis: Water molecules move. In animal cells, water can cross through the phospholipids (to a limited extent) and in plant cells and other cells with aquaporins, water can also cross through aquaporins (a type of protein). Water moves down its concentration gradient (from an area of higher water concentration to lower water concentration) without using cellular energy.

Answer:

	simple diffusion	facilitated diffusion	osmosis
molecules cross the membrane through proteins	❌	✔	✔ (in cases with aquaporins)
molecules move down their concentration gradient	✔	✔	✔
molecules move without using cellular energy	✔	✔	✔