Overview of Bacteria: Structure, Function, and Importance

Bacteria

Unicellular microorganisms, size few nanometers to ½ mm.

Decomposers

Organisms that break down dead organic matter.

Pathogenic Bacteria

Bacteria that cause disease in hosts.

Leeuwenhoek

First to observe bacteria using a microscope.

Robert Koch

Identified bacteria as disease-causing agents.

Louis Pasteur

Demonstrated bacteria's role in fermentation and disease.

Prokaryotic Cells

Cells without a nucleus, characteristic of bacteria.

Peptidoglycan

Component of bacterial cell walls, unique to bacteria.

Gram Positive

Bacteria that retain crystal violet stain, thicker walls.

Gram Negative

Bacteria that do not retain stain, thinner walls.

Bacillus

Rod-shaped bacteria, one of the morphological types.

Coccus

Spherical-shaped bacteria, one of the morphological types.

Spirillus

Spiral-shaped bacteria, one of the morphological types.

Binary Fission

Asexual reproduction method in bacteria, cell division.

Conjugation

Transfer of genetic material between bacteria via pilus.

DNA Plasmids

Small, independent DNA molecules within bacterial cells.

Bacterial Growth Phases

Lag, log, stationary, and death phases of growth.

Endospores

Dormant, resistant structures formed under stress.

Photosynthesizers

Bacteria that obtain energy from sunlight, like cyanobacteria.

Chemoautotrophs

Bacteria that derive energy from chemical reactions.

Heterotrophs

Bacteria that consume organic material for energy.

Mutualism

Interaction where all parties benefit from relationship.

Parasitism

Interaction where one organism benefits at another's expense.

Antibiotics

Substances that kill bacteria or inhibit their growth.

Superbugs

Bacteria resistant to multiple antibiotics, hard to treat.

Bioremediation

Use of bacteria to clean up environmental pollutants.