Photosynthesis and the Carbon Cycle

Video Transcription

Hi, I'm Jensen Morgan. We're going to talk about some great concepts in environmental science. Today's topic is photosynthesis and the carbon cycle. So let's get started. We're going to talk about photosynthesis, the carbon cycle, and humans' impacts on the carbon cycle.

Photosynthesis is the foundational process that provides energy for all life on earth. It captures and converts solar energy into energy that all life eventually consumes through various pathways. Vitally important to the process of photosynthesis is carbon. All living things on Earth are made of carbon and carbon as recycled. The process of photosynthesis is mapped out in the following equation.

Carbon dioxide combines with water and light to yield sugars and oxygen. Carbon flows between the sun, plants, animals, humans, and the atmosphere. Living things can perform the process of cellular respiration, including plants, which is when sugars are oxidized to produce energy, carbon dioxide, and water. This creates a reciprocal process where plants absorb carbon dioxide and produce oxygen, while many other living things reverse the process.

Important to note are the following. Volcanic activity releases large quantities of carbon dioxide into the atmosphere. Photosynthesis is a light dependent reaction that captures energy from the sun. Photosynthesis also has carbon-dependent reactions where the carbon dioxide is fixed into sugars. Cellular respiration is the breakdown of sugars using oxygen to produce carbon dioxide and energy. That carbon is then released through breath.

Most carbon on the planet is contained in or came from living organisms. When the majority of organisms die, they are recycled by decomposers in the soil, though sometimes they also form into fossil fuels. For example, plant matter the died is sometimes compressed over millions of years underground to form oil.

The carbon cycle is the map of how carbon flows and cycles on Earth. All living things on Earth are made up of carbon that originated as CO2 in our atmosphere. As I mentioned before, plants use carbon in the form of carbon dioxide combined with water and sunlight to create sugars and oxygen in order to grow. Animals then eat plants and absorb the carbon as sugars and other compounds.

Then animals grow and perform cellular respiration, releasing the carbon as carbon dioxide into the atmosphere through their breath. Completing the cycle, plants than absorb the carbon dioxide from the atmosphere once again during photosynthesis. The carbon cycle can occur in long-term intervals, such is dead organisms getting compressed over millions of years to form fossil fuels which are then extracted and burned by humans, thereby releasing the stored carbon back into the atmosphere as CO2.

And it also occurs in short-term intervals, such as plants storing it in photosynthesis, getting eaten by consumers who are eaten by higher consumers who then release CO2 during respiration before eventually dying and being broken down by decomposers such as fungi and bacteria, who cycle the carbon back into the system through decomposition.

Humans have also impacted the carbon cycle by releasing increased amounts of CO2 gas into the atmosphere, which traps heat and water vapor. The increased heat then has caused ice caps and glaciers to melt, which has changed ocean temperature and salinity, raised sea levels and affected climate and weather patterns. In addition, deforestation and land development has reduced the total amount of carbon stored in vegetative life, resulting in increased levels of CO2 in the atmosphere, which has affected the Earth's carbon cycle.

Now let's have a recap. We talked about photosynthesis, the carbon cycle, and humans' impact on the carbon cycle. Well, that's all for this tutorial. I hope these concepts have been helpful, and I look forward to next time. Bye.