Diffusion

• diffusion is the spreading out of particles resulting in a net movement from an area of high concentration to a low concentration
• oxygen, carbon dioxide and urea are molecules typically diffused
• cells need oxygen for respiration to be carried out by mitochondria
• cells are surrounded by high conc of oxygen as its transported through the bloodstream by the lungs
• as cells in the body are surrounded by a high conc. of oxygen the oxygen molecules will move in to the cell of lower conc. through diffusion
• as oxygen is moving in body cells in order for energy for respiration, a waste gas of CO$^2$ is produced causing a high conc. of CO$^2$ in the cells, so it will move out of the cell into the blood stream through diffusion
• Urea is a waste product produced inside cells and it moves out of cells through diffusion into the blood plasma and is excreted by kidneys
• the rates of diffusions is affected by

  • difference in concentrations= concentration gradient. The greater the conc. gradient the faster the diffusion
  • Temperate= the higher the temp the faster the diffusion as the the particles have more kinetic energy
  • The surface area of the membrane= the more surface area the greater the rate of diffusion
• which cell will have a greater rate of diffusion

  The first one as it has a larger surface area

  
• Would this cell have a faster of slower rate of diffusion?

  Faster because there is a greater concentration gradient