The process in which the molecules are moved uphill against the concentration gradient. Active transport always involves the expenditure of energy because the materials are pumped against the concentration gradient.
| Active transport | Passive transport | |
| 1. | It involves movement of molecules against the concentration gradient. | It involves movement of molecules along the concentration gradient. |
| 2. | It requires energy in the form of ATP molecules. | No energy is required. |
| 3. | It is a rapid movement. | It is a slow movement. |
| 4. | Movement of large molecules occur by active transport. | Only small molecules or water molecules are transported passively. |
