respiration in plants give some points also
Answers
You know that all living organisms respire in order to release energy from glucose and make it available in the form of ATP for chemical, osmotic and other work.
Plants are no exception. They need to respire virtually all the time in order to supply their energy needs. They are not able to use the ATP generated in photosynthesis for these purposes.
Plants respire in the normal way using glycolysis, Krebs cycle, oxidative phosphorylation etc.
Often, the respiration is masked by the fact that photosynthesis produces oxygen faster than respiration takes it up and photosynthesis uses carbon dioxide faster than respiration produces it. It is only in the dark that the full effects of respiration become apparent when photosynthesis is brought to a halt.
Plants need energy to take in mineral salts from the soil where they are present in very low concentration - this needs work (energy) to concentrate the mineral inside the plant. Plants growing in waterlogged soils (which are short of oxygen) cannot respire in their roots and soon show the symptoms of shortage of minerals (like yellow leaves). (Rice is interesting because it has a pithy stem through which it enables oxygen from above the water to get down to the roots and therefore rice thrives in "paddy fields".).
Water is taken into the plant partly with the help of energy, but most of the energy for water uptake is a result of the evaporation from the leaves "sucking" the water up. However, moving sugars around the plant seems to require energy as dead phloem cells do not transport sugars.
Complex chemicals (like proteins) need energy to make them from simple chemicals - again the plants need a supply of energy to do this.
During respiration, very little amount of gas exchanges takes place within the different parts of the plants. Therefore, each part takes care of its own energy requirements.
Roots, stems, and leaves of plants exchange gases for respiration separately. As we all know, leaves have tiny pores called as stomata, which is used for the exchange of gases. The oxygen, taken in through stomata is used by cells in the leaves to break down glucose into carbon dioxide and water.