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Q
Hello , I ’ ll keep this short and simple : Do plants breathe ?
Thanks , Jacqui
A
Hi Jacqui ,
Much goes on in a single breath . When we humans breathe , the body inhales oxygen through the lungs . The oxygen is then circulated to cells throughout the body via the bloodstream . At this point , the oxygen and glucose are converted to carbon dioxide and water , yielding energy , in a process called respiration or cellular respiration . The carbon dioxide is then returned to the lungs , where it is exhaled . With plant life , things work a bit differently . They don ’ t breathe , per se , since they don ’ t use muscles to draw in air , and they have no bloodstream to distribute oxygen . Plants do , however , respire and they rely on their leaves to perform the exchange of oxygen and carbon dioxide . More specifically , they rely on a series of tiny holes or pores found on the underside of the leaf . These holes are called the stomata ( singular , stoma ), and the number of stomata on a given leaf varies from plant to plant . In addition , plants also use their roots , stem , and to some extent , flowers to respire . Pores located on the branches of the plant are called lenticels . Stomata work hard , pulling double duty as they also play a part in photosynthesis . Photosynthesis and respiration are complementary processes that use and make the same substances — water , glucose , oxygen , and carbon dioxide — but in different ways . Using carbon dioxide and water , photosynthesis creates oxygen and glucose . As mentioned above , this glucose is then combined with oxygen to produce carbon dioxide , water , and energy . A key difference between the two processes is timing ; respiration can occur at any time , while photosynthesis will only take place if there is sunlight . This is why , in olden days , people would refrain from putting plants in their bedroom ; they feared the plants would steal the oxygen from the room ( via respiration ) and suffocate them during the night . Thankfully , this isn ’ t true . Plants release much more oxygen through photosynthesis than they consume during respiration , so there is nothing to be concerned with there . But back to the stomata . By opening and closing , the stomata not only control the intake of CO 2 for glucose production , but also allow air to escape during photosynthesis and water and carbon dioxide during respiration . The opening and closing of these pores is regulated by cells known as guard cells . Guard cells are produced in pairs and shaped like quarter moons placed tip to tip with the dark space between them forming the stomatal pore . Stomata are sensitive and easily affected by environmental conditions . Too hot and they stay open longer and in larger numbers . Too dry and they may close to help preserve moisture . When necessary , plants can control their stomata density by producing new leaves with fewer or greater numbers of pores commensurate with their immediate need . So , to answer the original question , yes , our little green friends actually do breathe — but in their own way .
Regards , Alan
Alan Ray has written five books and is a New York Times best-selling author . Additionally , he is an award-winning songwriter with awards from BMI and ASCAP , respectively . He lives in rural Tennessee with his wife , teenage son and two dogs : a South African Boerboel ( Bore-Bull ) and a Pomeranian / Frankenstein mix .
TRANSPIRATION
Transpiration is the process by which moisture is carried through plants from roots to stomata , where it is released to the atmosphere as vapor through stomata by way of guard cells . Studies have revealed that approximately 10 per cent of the moisture in the atmosphere is released by plants through transpiration . Transpiration rates vary widely depending on weather conditions , such as temperature , humidity , sunlight availability and intensity , precipitation , soil type and saturation , wind , land slope , and water use .
– water . usgs . gov
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