The bacteria breathe through two respiration processes: aerobic and anaerobic, this being the one used by most of these unicellular organisms due to their primitive evolution.
Some bacteria help us to live like those that allow us to digest food in our digestive system. Others, such as the one that causes bubonic plague or tuberculosis, can kill a person if they do not receive adequate and timely medical treatment..
The ancestors of modern bacteria appeared on earth approximately 4 billion years ago. They were the first life forms on the planet. They are so small that one gram of soil usually has 40 million bacteria. One millimeter of water could hold an average of one million.
Bacteria are found anywhere on earth, except those sterilized by man. Even in places where they are subjected to extreme temperatures or where there is a high concentration of toxic substances.
The cells of bacteria are quite different from those of any plant or animal. These cells lack a nucleus and other organelles within the membrane, except for ribosomes. Organisms whose cells lack a nucleus are called prokaryotes..
Most people only associate negative things with bacteria. But keep in mind that they are everywhere and have been around for so long that man could not have existed without them..
The oxygen in the air we breathe was probably created millions of years ago by the activity of bacteria.
Bacteria assimilate nitrogen from the atmosphere and release it for plants to use when they die. Plants cannot extract nitrogen from the air but from the soil, and thanks to bacteria they can complete this vital part of their metabolism.
The relationship between plants and bacteria has become so close in this regard, that some seeds are a container for bacteria to be used when they germinate..
Likewise, the human body contains enormous amounts of beneficial bacteria that do not affect us or help us in any way..
Bacteria found in the digestive system are essential for the absorption of certain types of nutrients. They also protect us from some harmful bacteria that can develop diseases.
All living things must have a constant source of energy to maintain the most basic vital functions. In some cases, that energy comes directly from the sun through photosynthesis, in others it devours other living beings, such as plants or animals..
The energy must be consumed and then it is converted into a suitable form such as adenosine triphosphate (ATP). There are several mechanisms to transform the original energy source into ATP.
The most efficient way is through aerobic respiration, which requires oxygen. This method will generate more ATP from the source.
However, if oxygen is not available, organisms can use other mechanisms to convert energy. Processes that do not need oxygen are called anaerobic.
During aerobic respiration, glucose from food is transformed into carbon dioxide and water by oxidation..
It produces a considerable amount of energy that organisms store in ATP molecules. All this process takes place in a part of the cells called mitochondria.
Most living things use aerobic respiration to release energy. Humans and other mammals, reptiles, birds, amphibians, fish, and insects use this type of respiration for energy.
Some organisms do not need oxygen to survive thanks to anaerobic respiration. This occurs in the most primitive types of bacteria, and scientists believe that the first organisms to appear on earth were anaerobic..
These beings proliferated when the Earth's atmosphere contained very little oxygen and, as their composition began to incorporate more oxygen over millions of years, new organisms evolved to adapt to this condition..
The appearance of oxygen is the result of plant life, which generates it from carbon dioxide through photosynthesis.
Anaerobic bacteria can also be beneficial to humans in many ways. Some actively participate in food production, through the fermentation process.
Other anaerobic bacteria play a role in wastewater treatment. Living in environments that could kill most creatures, and not just from a lack of oxygen, they consume waste materials, chemically transforming them into simpler compounds..
In anaerobic respiration, microorganisms convert glucose from food into ethanol and carbon dioxide to release energy. This energy is used by organisms for their survival. Anaerobic respiration produces less energy in the form of ATP than aerobic respiration.
Humans obtain energy through aerobic respiration. However, they can also use anaerobic respiration in the muscles.
When we do a demanding physical exercise, the oxygen supplied through the blood is consumed much faster by the muscle cells. The muscles then have to use glucose to convert it to lactic acid to release small amounts of energy..
During vigorous physical exercise or any type of heavy physical activity, most of the energy consumed by the muscles is produced by aerobic respiration.
Anaerobic muscular respiration only provides a little extra energy that is needed under demanding conditions of physical exertion. The lactic acid that is released in this anaerobic process accumulates in the muscles, causing cramps.
Muscle cramps can be relieved by taking a hot bath or with a massage. The hot water or massages, what they do is help improve blood circulation in the muscles.
By increasing the blood flow in the muscles, the supply of oxygen increases. This oxygen converts accumulated lactic acid into carbon dioxide and water and relieves cramps..