Lecture+9+slides

Prokaryotes

Single-celled organisms that make up the domains Bacteria and Archaea.

Binary fission

The method by which prokaryotes reproduce, dividing quickly every 1–3 hours under optimal conditions.

Horizontal gene transfer

The movement of genes between individual prokaryotes of different species, contributing to genetic diversity.

Gram-negative bacteria

Bacteria with complex cell walls containing lipopolysaccharides and less peptidoglycan, often more resistant to antibiotics.

Gram-positive bacteria

Bacteria with simpler cell walls that contain a large amount of peptidoglycan.

Osmosis

The movement of water across a semipermeable membrane, based on solute concentration.

Chemotaxis

The movement of prokaryotes toward or away from a chemical stimulus.

Autotrophs

Organisms that require CO2 or related compounds as a carbon source.

Heterotrophs

Organisms that require an organic nutrient to make other organic compounds.

Extremophiles

Archaea that live in extreme environments, such as extreme temperatures or salinities.

Biofilm

Surface-coating colonies formed by prokaryotes cooperating to utilize resources.

Methanogens

Obligate anaerobes that produce methane as a by-product of their metabolism.

Peptidoglycan

A network of sugar polymers cross-linked by polypeptides that makes up the bacterial cell wall.

Pathogenic bacteria

Bacteria that cause disease; they represent a small fraction of the total prokaryotic population.

CRISPR-Cas9

A gene editing tool developed from a prokaryotic immune system, used for altering genes.

Plasmid

Small rings of independently replicating DNA found in prokaryotes.

Chemoautotroph

An organism that obtains energy from inorganic chemicals and uses CO2 as a carbon source.

Facultative anaerobes

Organisms that can use O2 if present but can also carry out fermentation or anaerobic respiration.

Antibiotic resistance

The ability of bacteria to resist the effects of an antibiotic, often spread through horizontal gene transfer.