Prokaryotes

Prokaryotes

Oldest and simplest life forms, abundant for billions of years.

Bacteria

Also known as Eubacteria, one of two prokaryotic domains.

Archaea

Formerly called Archaebacteria, second prokaryotic domain.

Eukaryotes

Organisms with nuclear DNA, closest to Archaea.

Endosymbiosis

Theory explaining origin of mitochondria and chloroplasts.

Halobacteria

Salt-loving bacteria thriving in hypersaline environments.

Fimbriae

Hair-like structures aiding bacterial attachment.

Sex pilus

Structure facilitating bacterial conjugation.

Nucleoid

Region containing prokaryotic DNA, not membrane-bound.

Binary fission

Asexual reproduction method in prokaryotes.

Gram-positive bacteria

Thicker peptidoglycan layer, retains crystal violet stain.

Gram-negative bacteria

Thinner peptidoglycan, more resistant to antibiotics.

Peptidoglycan

Structural component of bacterial cell walls.

Plasma membrane

Barrier surrounding all prokaryotic cells.

Cocci

Spherical bacterial shape.

Bacilli

Rod-shaped bacterial form.

Spirilli

Spiral-shaped bacteria.

Genetic recombination

Process enhancing genetic diversity in bacteria. Occurs thru horizontal gene transfer (no sexual reproduction and not a form a of reproduction)

Transformation

Uptake of foreign DNA from surroundings. The cell takes up prokaryotic DNA directly from the environment , the DNA may remain separate as plasmid DNA or be incorporated into the host genome.

Transduction

Gene transfer via bacteriophages.

Conjugation

Bacterial mating process involving plasmid transfer.

Antibiotic resistance

Ability of bacteria to survive antibiotic treatment.

Tuberculosis (TB)

Infectious disease caused by Mycobacterium tuberculosis.

Lyme Disease

Caused by Borrelia bacteria, transmitted by ticks.

Dental cavities

Tooth decay caused by bacterial biofilms.

Peptic ulcers

Stomach ulcers caused by Helicobacter pylori.

Beneficial prokaryotes

Prokaryotes aiding in nutrient cycles and food production.

Biotechnology

Use of prokaryotes in producing cheese, wine, and yogurt.

Oil degradation

Bacteria used to clean up oil spills.

Prokaryotes

Oldest and simplest life forms, unicellular.

Bacteria

Domain of prokaryotes with peptidoglycan cell walls.

Archaea

Domain of prokaryotes lacking peptidoglycan.

Endosymbiosis

Theory explaining mitochondria and chloroplast origins.

Halobacteria

Salt-loving bacteria thriving in hypersaline environments.

Fimbriae

Hair-like structures aiding in bacterial adhesion.

Sex pilus

Structure facilitating bacterial conjugation.

Flagella

Tail-like structure for bacterial motility.

Nucleoid

Region containing bacterial circular chromosome.

Binary fission

Asexual reproduction method in prokaryotes.

Gram-positive

Bacteria with thick peptidoglycan cell walls.

Gram-negative

Bacteria with thin peptidoglycan and outer membrane.

Peptidoglycan

Polymer forming bacterial cell wall structure.

Plasmids

Small DNA molecules carrying advantageous genes.

Transformation

Uptake of foreign DNA from surroundings.

Transduction

Gene transfer via bacteriophages between bacteria. (a bacteriophage injects DNA into the cell that contains a small fragment of DNA from a different prokaryote)

Conjugation

Direct transfer of DNA between bacteria. (DNA is transferred from one cell to another via a pilus that connects the 2 cells, and plasmids may encode advantageous info)

E. coli

Model organism for studying bacterial genetics.

Antibiotic resistance

Ability of bacteria to survive antibiotic treatment.

Human diseases

Infections caused by pathogenic bacteria.

Tuberculosis

Infection by Mycobacterium tuberculosis affecting lungs.

Lyme disease

Caused by Borrelia, transmitted by ticks.

Dental cavities

Tooth decay caused by bacterial biofilms.

Beneficial prokaryotes

Prokaryotes aiding in nutrient cycles and food.

Biotechnology

Use of organisms for practical applications.

Genetic diversity

Variability in genetic traits among bacteria.

Rapid reproduction

Fast population growth through binary fission.

Mutation

Change in DNA sequence leading to diversity.

Horizontal gene transfer

Transfer of genes between organisms, not offspring.