Photosynthesis and Cell Respiration

By Grace Pittinger and Elliott McFarlane


Cellular respiration and photosynthesis are processes that occur in the cells of plants and animals. They rely on each other to take place. Photosynthesis is an act of plants going through a process to receive the nutrients that they need. Photosynthesis occurs inside of plant cell, but more specifically the chloroplasts. Water, energy from sunlight, and carbon dioxide are all needed in order for the plant to undergo photosynthesis. Cellular respiration happens so that animals can receive the oxygen and energy that they need. Cellular respiration takes place inside of an animal cell, and more specifically the mitochondria. Oxygen and carbohydrates are both needed in order for the animal to undergo cellular respiration.

Plant Cell- Photosynthesis

Big image


Photosynthesis occurs when carbon dioxide (CO2), Water (H2O), and energy from the sun is taken in by a plant cell and is converted to oxygen and sugar, to be released into the environment. The roots of a plant absorb water from the soil in the ground, and then the stem transports the water to the leaves by capillary action. Carbon dioxide is absorbed from the air into the plant, and the energy from sunlight is taken in as well, to help begin photosynthesis. The leaves then conduct photosynthesis. Inside the leaves, the chloroplasts go through a series of chemical reactions and processes that make up photosynthesis. After all of the processes and reactions are completed, the plant releases oxygen (O2) and sugar/starch into the air and environment.

Animal Cell- Cellular Respiration

Big image

Cellular Respiration

Cellular respiration occurs when sugar is consumed by an animal and is broken down. The glucose is broken down in the small intestine and goes through a process called glycolysis, where the glucose is broken down into smaller particles called carbon pyruvates, and they enter into the mitochondria inside of an animal cell. For this to happen, oxygen is needed. Oxygen is taken in by the animal. Pyruvates enter into the mitochondria and go through a process called the kreb’s cycle. Here, the pyruvates are broken down, and CO2 or carbon dioxide is made, and two ATPs are made. ATP stands for Adenosine tri-phosphate, which is a form of energy that fuels animal’s activities. Then the electron chain takes place on the inner membrane of the mitochondria, and 32-34 more ATPs are made, as well as water (H2O). Carbon dioxide is transported through the bloodstream up to the lungs, where it is released into the air in the environment.


Photosynthesis relies on cellular respiration, and vice versa. If you think about it, photosynthesis and cellular respiration are replicas of each other, just switched! Photosynthesis needs carbon dioxide, water, and energy to occur, and cellular respiration results in the making of carbon dioxide, water, and energy. So in a sense, photosynthesis needs cellular respiration to give it what it needs. The other way around is that cellular respiration needs oxygen and sugar to occur, and photosynthesis results in making both oxygen and sugar. In a way, cellular respiration and photosynthesis work together in a cycle, each supplying the other with what they need to follow through.

Example: An Apple Tree and a Human

When an apple tree goes through photosynthesis, it produces a form of sugar known as apples. It also produces oxygen to release out into the environment. When a human picks apples off of that tree, they intake the apple and digest it, as well as intaking the oxygen produced by the apple tree. Then, the glucose from the apple is broken down, and the oxygen from the plant is used to power cellular respiration in a human cell. The human then exhales carbon dioxide into the air, that is circled back around to the apple, allowing the process to restart.


Cellular Respiration: C₆H₁₂O₆ + O₂ → CO₂ + H₂O + energy
Photosynthesis: 6CO2 + 6H2O ------> C6H12O6 + 6O2

Helpful Links and Tools

Photosynthesis and respiration | Chemistry for All | The Fuse School