what is diffusion and active transport
Answers
Diffusion is the process in which movement of molecules takes place from a region of their higher concentration to lower concentration till the concentrations become equal on both the sides. This is generally applicable for the movement of gaseous substances. The taking in of carbon dioxide from the air and release of oxygen into the air by the plants during the process of photosynthesis take place by diffusion. The taking in of oxygen into the blood from lungs and the release of carbon dioxide from the blood into the lungs also take place by diffusion.
Active transport is the movement of ions and electrolytes, which takes place across the membrane by using energy produced by the cell. For example, movement of ions into or out of the cell. In general, molecules move from an area of higher their concentration to an area of their lower concentration without the expense of energy by diffusion or osmosis. Active transport occurs when molecules move across a cell membrane from a region of their lower concentration to a region of their higher concentration. In order to get molecules move against the concentration gradient, work must be done, hence energy is required.