diffusion

• Diffusion is the movement of particles from an area of high concentration to low concentration.
• The rate of diffusion depends on temperature, surface area, and concentration gradient.
• cells need glucose and oxygen to survive, however , they also need to get rid of waste products like carbon dioxide
• these materials move in and out a cell aross the cell membrane
• the materials move into or out of the cells by a process called diffusion.
• diffusion is important for respiration. carbon dioxide is a waste product of respiration - all cells make it and need to get rid of it
• the carbon dioxide concentration inside the respiring cells is higher than the the blood flowing past them, this means that the carbon dioxide will diffuse out of the cells and into the blood where it carried to the lungs to be breathed out
• cells need oxygen for respiration. blood flowing past the body has lots of oxygen in it - a respiring cell uses up oxygen so its concentration is lower than the oxygen concentration flowing past it. so, oxygen diffuses out of the blood into the respiring cells.
• diffusion also occurs in plants; they need to take in carbon dioxide for photosynthesis. photosynthesis is a process that makes food for the plant and it happens mainly in the leaves
• the concentration of carbon dioxide in the air outside the leaf is higher than it is in the air spaces inside the leaf. so the carbon dioxide moves into the leaf by diffusion and then diffuses into the plant cells in order to be used for photosynthesis