Photosynthesis and Cellular Respiration

Plants use two processes to make food for themselves. They are photosynthesis and cellular respiration. One is used during day and one is used during night. Calvin’s explanation of when plants use these processes is that photosynthesis occurs when it is light, and cellular respiration occurs when it is dark. I agree with this because plants need light energy which comes from the sun to go through photosynthesis and at night, they use the glucose they’d made during day because the sunlight is gone. Photosynthesis is a process plants use during the day to break down resources to make food for themselves. This occurs in the chloroplasts of plant cells.

The resources they need are light energy, carbon dioxide, and water. Light energy travels to Earth by light waves from the sun. Carbon dioxide is taken in through tiny holes in leaves called stomata. Water is absorbed through their roots and travels from there, up to the leaves through tubes in the stem. When light energy, carbon dioxide, and water all get to the chloroplast, photosynthesis occurs. When light energy hits the carbon dioxide and water molecules, it is transformed into chemical energy and they all break up and rearrange to create glucose (a type of sugar). Oxygen is a waste product of photosynthesis and gets released with the glucose when the process is done.

The photosynthesis equation is CO2(carbon dioxide)+H2O(water)+light energy=C6H12O6(glucose) & O2(oxygen). Cellular respiration is a process plants use at night for energy. This happens in the mitochondria’s of plant cells. The resources needed for this are energy, carbon dioxide, water, and heat. Cellular respiration is the inverse of photosynthesis. The way this works is glucose and oxygen enter the mitochondria, which releases chemical energy for later use. Then, everything is sent out to give other cells more energy. This is how the plant can still get energy at night. Cellular respiration is used differently for both plant and animal cells. In animal cells, this can happen during the day and night. For plant cells, this is used during the night. The reason plants mostly use cellular respiration at night is that during day, the resources needed for this process are made during photosynthesis. If the plants were to use cellular respiration during the day, then all the glucose and oxygen would be gone by time night comes. If those resources are gone, then the plant could die from not being able to get enough energy.

Many people may think that Mika is correct, however this is wrong. He claimed that photosynthesis occurs when it is light, and cellular respiration occurs when it is both light and dark. Mika is wrong because he wasn’t supposed to talk about both plant and animal cells, only plant cells. It was already wrong because photosynthesis only occurs in plants and cellular respiration only happens in plants at night, but occurs in animals during both day and night. Calvin is correct because plants use photosynthesis during the day to make glucose and oxygen for cellular respiration to break back down and give to other parts of the plant for overnight energy.

The way plants get their energy is different from animals. Animals have to eat other biotic factors to get energy, and plants have to use natural resources to make their own foods. All animals have to do is catch and feast on their prey. Plants have to use two processes called photosynthesis and cellular respiration for food.