Photosynthesis and Cellular Respiration

1328 Words6 Pages
Photosynthesis and Cellular Respiration Have you ever sat back and wondered where you get the ability to do some of the everyday things. Things like a simple smile or frown takes energy. To raise ones hand takes energy. What is this thing that is so important to every living thing we call energy? Webster defines energy as ability to be active the physical or mental strength that allows you to do things. Energy is also defined as usable power that comes from heat, electricity, etc. Organisms cannot exist without energy. So how do organisms get the energy they need? When the world began there was not a wide source of oxygen. Therefore cells could not use oxygen to produce food need to survive. Those cells most likely used fermentation as a source of getting necessary nutrients. Long ago all cells were prokaryotic. According to The Theme of Evolution in Glycolysis and Cellular Respiration (2015), Eukaryotic cells came about through endosymbiosis and evolution. In other words, cells began to live inside of larger cells. This may have occurred when the larger cell ate the smaller cell and the smaller cell refused to give up and die. Many generation pass and the two cells develop a dependence for the other. They cannot survive apart. The smaller organism eventually becomes the mitochondrion. Plants and some protist, like algae, use light as their main source of energy. Sunlight is usually the light source used. Through a process called photosynthesis, energy obtained from light is converted into chemical energy to be used by the plant as a source of sustenance. Along with carbon dioxide and water, plants use the sun energy to make sugar. There are two types of photosynthesis, oxygenic photosynthesis and anoxygenic photosynthesis. In order to understand photosynthesis you have to understand the site where it occurs. Chloroplast is where the process occurs.

More about Photosynthesis and Cellular Respiration

Open Document