bacteria and arcaea PPT

Prokaryotes

Unicellular organisms that lack a membrane-bound nucleus, including bacteria and archaea.

Eukaryotes

Organisms whose cells have a membrane-bound nucleus and organelles.

Antibiotics

Molecules that kill bacteria or inhibit their growth, produced naturally by some soil bacteria and fungi.

Microbiome

The community of microbes that naturally inhabit a particular area.

Extremophiles

Organisms, mainly bacteria and archaea, that thrive in extreme environmental conditions.

(hydrothermal vents, pH<1.0, 0 degrees Celsius, water that is 5- 10 saltier)

Virulence

The ability of a pathogen to cause disease, which is a heritable and variable trait.

Endospores

Tough, thick-walled, dormant structures formed by some bacteria during environmental stress.

Biofilm

A community of bacteria adhering to a surface, enmeshed in a polysaccharide-rich matrix.

Nitrogen fixation

The process by which certain bacteria convert atmospheric nitrogen (N2) into ammonia (NH3), making it usable by organisms.

Gram-positive bacteria

Bacteria that have a thick peptidoglycan cell wall and retain the crystal violet stain, appearing purple under a microscope.

Gram-negative bacteria

Bacteria with a thin peptidoglycan layer and an outer phospholipid bilayer, which do not retain crystal violet stain and appear pink.

Lateral gene transfer

The process through which bacteria can acquire new genetic material from other organisms, not just through reproduction.

Cyanobacteria

Photosynthetic bacteria responsible for the oxygenation of Earth’s atmosphere by performing oxygenic photosynthesis.

Koch’s postulates

Four criteria established by Robert Koch to prove a causal relationship between a microorganism and a disease.

Pathogen

An organism, usually a bacterium, that causes disease.

Transformation

The process by which bacteria take up foreign DNA from their environment.

Conjugation

A process of genetic transfer between bacteria through direct cell-to-cell contact.

Transduction

The process where viruses transfer DNA between prokaryotic cells.

Morphological Diversity

The variety of shapes and structures found in bacteria and archaea, including cocci, bacilli, and spirilli.

Nodule

A root structure in plants that houses nitrogen-fixing bacteria.

Bacillus anthracis

The bacterium that causes anthrax, identified in Koch's postulates.