Introduction to Cellular Respiration
Our human body contains trillions of cells, which perform the various functions in our body, like breathing. Cells need to work around the clock and they need to be replenished with energy continuously; or else our body won’t function. Imagine, if your dog did not have energy, then she would not have been able to wag its tail or play “fetch the ball” with you. Cellular respiration is a biological process where cells reload themselves with energy.
How do these Minute Organisms do it?
When you chomp food, your body changes the food into a special kind of sugar (like the unique sugar coating on candies) called glucose. Glucose is like the gas your father pumps into the car to keep it running. The insulin hormone transports this glucose to those hard working cells.
Steps of Cellular Respiration
This glucose which contains six carbon atoms is split in the cell through Glycolysis. This process is anaerobic as without the help of oxygen, 2 molecules called pyruvate and 2 energy molecules called ATP (explained later) are formed. Think of inserting a dollar bill into a vending machine to generate quarters to be used as your bus fare in your ride to the zoo.
Cells also need the most important ingredient which is oxygen. We breathe in oxygen. The more oxygen we breathe in, the more energy we produce. That is why when you are exercising, your sports teacher always asks you to breathe more and more consciously.
In the aerobic process, the oxygen is used with this pyruvate ( remember the molecules formed from the fuel like component called glucose) to produce the energy molecules ATP.
The first part is called the Kreb’s cycle, which is a succession of enzymatic reactions, where the acetate, from the pyruvate, is oxidized and changed into energy molecules and carbon dioxide and water are released.
The Electron Transfer Chain also is a series of chemical reactions, where electrons are shuttled down, and energy from the oxygen atoms are converted into hydrogen atoms, which produce ATP.
This energy is stored and used through molecules called adenosine triphosphate (ATP) in a special compartment called the mitochondria. They are called the power boosters of the cells, as they supply energy to the cell. They look like sausages. They keep unwanted particles out of the cells.
They also regulate the water amounts in the cells and crumble proteins etc. When your mother tells you to eat fish and drink lots of milk, she is doing this for your own good and not hers. Your body needs proteins for again those laborious cells; which are producing energy to keep you kicking the football to the goalpost every time. The protein is further broken down into amino acids that are used in restocking the cells and manufacturing new cells.
Cellular Respiration can be summarized as
Glucose + Oxygen= Carbon Dioxide + Water + ATP (Energy)
Cellular Respiration in Plants
But in plants, cellular respiration is slightly different. Here through a simple process called photosynthesis, plants use sunlight to turn carbon dioxide and water into glucose. Also, photosynthesis occurs only when there is sunlight.
Fun Facts about Cellular Respiration
- Anaerobic cellular respiration produces only 2 ATP molecules compared to Aerobic cellular respiration which produces 38 ATP molecules per cell.
- If we don’t breathe in more during exercises, our body produces lactic acid which causes the terrible pain in our muscles and joints.