Photosynthesis and Cellular Respiration
Photosynthesis is a reaction that occurs in plant cells. This reaction takes place in the cells of leaves; they use carbon dioxide and water. The chloroplasts in the leaf cells use the energy that is gained from the sunlight, to reorganize the atoms from the carbon dioxide and the water to create sugars, such as glucose. Oxygen is produced through photosynthesis; the oxygen is then released through pores in the leaves into the atmosphere. Cellular respiration and photosynthesis go hand in hand. Cellular respiration uses the oxygen that the plants produce to break down the chemical bonds in the sugars and convert it into ATP (adenosine triphosphate), this is produced in the mitochondria.
Photosynthesis creates the ultimate source of energy for just about every ecosystem that is found on Earth. The chemical energy that is created through photosynthesis is then stored in the molecules of sugar. Organisms that produce their own organic matter are known as autotrophs; these would classify plants. There are two cycles when it comes to photosynthesis, the light cycle, and the Calvin cycle. In the light reaction, this is where the chlorophyll on the plant cell absorbs the sunlight and converts it into ATP energy and NADPH. During the light reaction, water is split, and then oxygen is released through the pores of the leaves. Now the Calvin cycle uses what is made during the light reaction to help fuel the creation of sugar from carbon dioxide. The stroma dissolves the enzymes that are required to fuel the Calvin cycle, and the ATP that is created is used to help synthesis the sugars. The NADPH that was created in the light reaction is a high source of energy that is used in synthesizing the glucose from the carbon dioxide.
Cellular respiration is when a cell releases two gases into its surroundings, the cell will take in oxygen in its gas form. The waste that it gets rid of is in the form of CO2, or carbon dioxide. When a person inhales, they inhale oxygen that is then inhaled into the lungs and enters the bloodstream. Just like the carbon dioxide that is in your bloodstream is sent to your lungs and expelled as the exhale. The carbon dioxide that has been expelled was created in the mitochondria of cells. When you think of a car, it requires the O2, oxygen, to break down the fuel. It is the same with the body; we require oxygen to break down the fuel. Cellular respiration is like internal combustion; it is the main way that the food is broken down into chemical energy and turned into ATP. Cellular respiration requires oxygen, so it is an aerobic process. The waste of cellular respiration, carbon dioxide, and water are the products that are used for photosynthesis. It is just like the products of photosynthesis, glucose, and oxygen are used in cellular respiration.
Cellular respiration and photosynthesis go hand in hand; they both recycle the waste of the other and use it to create energy that the cells use to function. For example, when humans exhale the carbon dioxide that is in their bodies, this is due to cellular respiration. Carbon dioxide is considered waste, but when you exhale it, the plants absorb it and use it to help with photosynthesis. So, the oxygen that is created through photosynthesis is then released and is used by humans and animals. This is a cycle that continuously occurs; it is part of the cycle of life.
Reading through the textbook, you read that according to Darwin, cells evolved and changed based on their environment. Thinking about how plants usually get carbon dioxide through the air, it is different in different weather and different climates. Plants had to evolve and change to adapt to the climate that they were growing in, this way they could still acquire the carbon dioxide that they require to continue to produce the oxygen that all living life requires to survive. There are plants that do not open their petals to absorb the carbon dioxide until it is late at night, or there are some that open only in the mornings. This is an evolutionary trait that was gained due to certain climates and temperatures.
References
Eric J. Simon, Jean L. Dickey, Jane B. Reece, and Kelly A. Hogan. (2016). Campbell Essential Biology, 5th Ed. Benjamin-Cummings Publishing CompanyLast Name, F. M. (Year).