Bacteria

The Bacterial Cell As prokaryotes bacteria lack a nucleus and have very simple cell structures. Anton Van Leeuwenhoek was the first to discover bacteria in the late 1600’s

Bacterial Shapes

Obtaining Food and Energy Autotrophs: Some bacteria can produce energy all on their own Phototrophs: Use sunlight to conduct photosynthesis. Chemotrophs: Use chemicals to produce energy. Heterotrophs: Some bacteria must consume other organisms from dead and decaying materials to byproducts of other organisms.

Asexual Reproduction Bacteria reproduce and multiply asexually by cloning themselves in a process called binary fission. Under the right conditions bacteria can reproduce once every 20 minutes!

Sexual Reproduction Some bacteria have developed means of sexual interaction. During a process called conjugation one bacteria will transfer some of its genetic material to another bacteria. The result is genetic diversity. Conjugation does not directly reproduce bacteria.

Endospore Formation A small, rounded, thick-walled, resting cell that forms inside a bacterial cell. It contains the cell’s genetic material and some of its cytoplasm. Endospores can survive under extremely harsh conditions. Once the conditions improve the endospore “awakens” and develops into a new bacteria.

The Role of Bacteria Bacteria have played an incredibly important role in the history of life on Earth and in the history of humanity in both positive and negative ways.

Oxygen Production Starting from around 3.5 billion years ago autotrophic bacteria have been producing atmospheric oxygen to fuel other organisms.

Food Production Many bacteria play a role in producing various fermented foods. Pasteurization can preserve foods from bacteria.

Environmental Recycling Some bacteria live in the soil. These bacteria decompose dead and decaying matter such as leaves and dead animals. The byproducts are then infused into the soil and reused by plants and other organisms. Nitrogen-fixing bacteria convert nitrogen into fertilizers for plants.

Environmental Cleaning Some bacteria can dissolve dangerous chemicals such as oil and convert them into harmless substances.

Health and Medicine There are certain types of bacteria which live inside our bodies and aid us in producing vitamins and digesting food. Scientists have genetically engineered various bacteria to produce medicines such as insulin to aid diabetics.