Gas exchange in plants

• Gas exchange


  The swapping of gases between the organism and its environment
• Tissue


  A group of similar specialized cells working together for a purpose
• Photosynthesis


  Carbon dioxide + water + energy from sun produces glucose + oxygen
• Respiration


  Glucose + oxygen produces carbon dioxide + water + energy
• Glucose


  A type of sugar, a store of chemical potential energy
• Stoma (plural: stomata)


  Small holes or pores in the bottom of a leaf that let gases in and out
• Vessel


  A tube that transfers a fluid in an organism, e.g. a blood vessel
• Diffusion


  When particles move randomly from an area of high concentration to an area of low concentration
• Plants exchange gases through stomata in their leaves
• Plants respire all the time but only photosynthesize during the day
• During the day


  Photosynthesis happens faster than respiration, so overall carbon dioxide moves into the leaves and oxygen moves out
• At night


  Respiration happens but photosynthesis doesn't, so overall carbon dioxide moves out of the leaves and oxygen moves in
• Gas exchange surfaces


  • Have a large surface area
  • Are very thin
  • Have lots of vessels
• Animals have lungs for gas exchange, plants have leaves
• Lungs have millions of tiny air sacs called alveoli, leaves have spongy tissue with air spaces
• Lungs and leaves are both very vascular with lots of blood/fluid vessels
• Lungs physically move air in and out, plants use diffusion and water pressure to move gases