Chapter 26: Bacteria and Archaea

A comprehensive set of vocabulary flashcards based on the key concepts from the lecture notes on Bacteria and Archaea.

Domain Bacteria

Prokaryotes characterized by unique peptidoglycan cell walls and 70s ribosomes.

Domain Archaea

Prokaryotes with unique phospholipids in their plasma membrane and 80s ribosomes.

Peptidoglycan

A polymer that consists of sugars and amino acids, forming the cell wall of bacteria.

Ubiquitous

Present in all places; refers to the widespread occurrence of bacteria and archaea.

Extremophiles

Organisms, particularly prokaryotes, that thrive in extreme environmental conditions.

Methanogens

A type of archaea that produce methane as a metabolic byproduct, often found in anaerobic environments.

Bioremediation

The use of bacteria and archaea to degrade pollutants and restore environmental quality.

Virulence

The ability of a pathogen to cause disease in a host.

Antibiotics

Substances that kill bacteria or inhibit their growth.

Koch's Postulates

Four criteria established to link a specific microbe to a specific disease.

Gram-positive bacteria

Bacteria with a thick peptidoglycan cell wall that stain bluish purple.

Gram-negative bacteria

Bacteria with a thin peptidoglycan wall and an outer phospholipid bilayer that stain reddish pink.

Endospores

A resistant structure formed inside some bacteria that allows them to survive extreme conditions.

Binary fission

The asexual reproduction process in prokaryotes resulting in genetically identical daughter cells.

Conjugation

A process where two bacteria connect and transfer genetic material via a sex pilus.

Transduction

The transfer of bacterial DNA through a virus.

Transformation

The uptake of foreign DNA from the environment by a bacterial cell.

Chemolithotroph

Organisms that obtain energy by oxidizing inorganic molecules.

Phototroph

Organisms that derive energy from light.

Chemoorganotroph

Organisms that obtain energy from organic compounds.

Autotroph

Organisms that produce their own organic molecules from inorganic substances.

Heterotroph

Organisms that obtain organic molecules by consuming other organisms.

Nitrogen fixation

The process of converting nitrogen gas (N2) into ammonia (NH3) by certain bacteria.

Cyanobacteria

Photosynthetic bacteria that produce oxygen as a by-product of photosynthesis.

Nitrogen cycle

The series of processes by which nitrogen and its compounds are interconverted in the environment.

Hydrothermal vents

Deep-sea ecosystems supported by energy from geothermal heat rather than sunlight.

Human microbiome

The collection of microbes residing in or on the human body, contributing to health.

Pathogen

An organism that causes disease, especially bacteria and viruses.

Germ theory of disease

The theory that certain diseases are caused by specific microorganisms.

Taq polymerase

A heat-stable enzyme used in PCR, isolated from a thermophilic bacterium.

Environmental pollutants

Substances that cause harm to the environment, often decomposed by bacteria in bioremediation.

Gliding movement

A mode of bacterial motility that does not require flagella.

Plasmid

A small, circular DNA molecule found in bacteria that can replicate independently of chromosomes.

Naked DNA

DNA not associated with histone proteins, characteristic of bacterial DNA.

Coccus

A spherical-shaped bacterium.

Bacillus

A rod-shaped bacterium.

Spirillum

A spiral-shaped bacterium.

Capsule

A thick gel layer outside the cell wall of some bacteria, typically found in pathogens.

Anaerobic habitats

Environments where oxygen is absent, suitable for certain archaea like methanogens.

Metagenomics

The study of genetic material recovered directly from environmental samples.