Why are gradients important in diffusion and osmosis?
The gradient determines the direction of movement for particles.
The particles will move from an area of high concentration to an area of low concentration. This direction of movement is described as movement * with * the concentration gradient.
This video discusses the topic of diffusion and concentration gradients.
This video discusses the topic of osmosis and how different solution types (hypotonic, isotonic and hypertonic) determine concentration gradients which determine the direction water will move.
Active transport moves materials from where they are less concentrated to where they are more concentrated. This movement is said to be * against * the concentration gradient. Movement of materials against the concentration gradient requires the use of energy and is referred to as active transport.
Hope this helps!