What are bacteria? What is the structure of bacteria?

As is known, bacteria are single-celled organisms, microscopic in size that the naked eye cannot see, living and thriving in different environments. So specifically, what is bacteria and what is the structure of bacteria?

Bacteria are organisms that play a very important role in the environment and human health. There are many different types of bacteria. Join the article below to find out what bacteria are and how bacteria are structured.

Learn about bacteria

Bacteria are organisms that are found all over the world

Bacteria, also known as germs, are extremely small single-celled prokaryotes, some of which are also parasites. Bacteria are single-celled organisms, not belonging to the group of plants or animals, with a very simple cell structure without a nucleus and microscopic size. Contains cytoskeleton and organelles such as mitochondria and chloroplasts.

It is the most abundant group in the living world. Bacteria are present everywhere, in soil, water, radioactive waste and even inside other organisms. Bacteria are thought to have first appeared on earth about 4 billion years ago. Fossils of bacteria-like organisms are the oldest known fossils. One gram of soil usually contains up to 40 million bacterial cells. Meanwhile, 1ml of soft drink contains about 1 million bacteria cells. About 5 billion bacteria are estimated to exist on earth, and most of the earth's biomass is thought to be made up of bacteria.

People often think that bacteria are harmful organisms, but they are not. Many types of bacteria are used for useful purposes. They support many life forms, both plant and animal, and are used in industrial and pharmaceutical processes. However, there are also some bacteria that cause disease in humans, such as gram-negative bacteria Escherichia coli causing  Escherichia coli infection or bacterial meningitis , bacterial leukocytosis .

Today's Bacteria

There are countless different types of bacteria. The way bacteria are classified is according to their shape such as spherical, rod, spiral, comma (comma) or filamentous....

Cocci are spherical bacteria but can also be oval or candle shaped, cocci also known as cocci, with an average diameter of about 1 μm. Cocci are divided into: Diphtheria, streptococci, staphylococci, bacilli and spirochetes:

• Diphtheria : These are bacteria that stand in pairs like pneumococcus and gonococci.
• Streptococcus : These are bacteria that stand in a chain.
• Staphylococci : These are bridges that stand in clusters like bunches of grapes.
• Bacilli : This is the common name for rod-shaped bacteria. Available in sizes from 0.5 - 1 - 4μm.
• Spiral : The name for bacteria with two or more helices, the size of which varies from 0.5 - 3 - 5 - 40μm. The spirochetes are mostly saprophytic, with very little pathogenicity.

Bacterial morphology and structure

Bacteria have a simple structure

Bacterial cells are structurally different from plant and animal cells. Bacteria are prokaryotes which means they do not have a nucleus.

Bacterial cells will include:

• Cell wall: The outermost layer that surrounds bacteria, keeping them in a certain shape. The cell wall has the function of maintaining the morphology, osmotic pressure inside the cell, protecting the cell against physical and chemical agents and carrying out the charge at the cell surface. Bacteria are divided into Gram- and Gram+ based on their chemical properties and their ability to capture dyes.
• Mucous capsule: The mucus coat is the outer layer of the cell wall, this is a protective layer for bacteria to avoid phagocytosis by white blood cells, in addition, this is also a place to store nutrients. The chemical composition of the mucus coat determines the antigenicity of the bacteria.
• Cytoplasmic membrane: The membrane located under the cell wall, also known as the plasma membrane, the membrane has a thickness of 4-5 nm, accounting for 10-15% of the cell weight of bacteria. The cytoplasmic membrane has many important functions such as: Maintaining osmotic pressure, ensuring active accumulation of nutrients and excretion of metabolic products.
• Cytoplasm: This is the main component of the bacterial cell, containing genetic material and ribosomes.
• Ribosome: This is the site of cellular protein synthesis, mainly RNA and proteins.
• Natural nucleus: Bacterial nucleosome consists of only one ring-shaped chromosome made up of a single DNA molecule, containing the essential genetic information of bacteria, bacteria do not have a nuclear membrane.
• Capillaries and villi: Capillaries are mobile organs of bacteria, not all bacteria have flagella. Villi are hairs that grow all over the surface of some bacteria, making it easier for them to stick to the substrate, increasing the contact area with food.

Nutrition of bacteria

Bacteria take up nutrients in different ways:

• Heterotrophic bacteria will consume organic carbon. Most of them absorb from dead organic matter, such as decomposing meat.
• Autotrophic bacteria will create their own food through photosynthesis, using sunlight, water and CO2, or chemical synthesis, using CO2, water and chemicals such as ammonia, nitrogen, sulfur, etc. sulfur and other substances.
• Phototrophic is the name for bacteria that use phototrophs. Some types, like cyanobacteria, produce oxygen. They play an important role in creating oxygen in the earth's atmosphere.
• Chemoautotrophs: Bacteria that derive energy from chemical synthesis.

Bacterial reproduction

Bacteria normally reproduce by dividing into 2 daughter cells

The main mode of reproduction in bacteria is cell duplication, which divides from one parent cell into two daughter cells. Each different type of bacteria will have a different growth rate, producing a generation every 10 - 30 minutes. In addition, bacteria also have sexual reproduction through the form of conjugation between two cells.

Above is some information about bacteria and the structure of bacteria  that you need to know that has been  compiled by SignsSymptomsList for readers. We hope that you have found some interesting and useful information for yourself through this article.