Bio 1201 1-3 prokaryotes

What are the three domains of life according to Carl Woese's phylogenetic tree?

Bacteria, Archaea, and Eukarya.

What distinguishes prokaryotes from eukaryotes in terms of cellular structure?

Prokaryotes are single-celled organisms lacking intracellular organelles.

How long have prokaryotes existed compared to eukaryotes?

Prokaryotes have been abundant for over a billion years before eukaryotes.

What percentage of prokaryotes are known to cause disease?

Less than 1%.

In what extreme environments can prokaryotes thrive?

Prokaryotes can thrive in acidic, salty, cold, or hot environments.

What is the typical size range of prokaryotic cells?

Most prokaryotes are less than 1 mm in diameter.

What is the structure of the prokaryotic chromosome?

It is a single, circular, double-stranded DNA found in the nucleoid region.

How do prokaryotes primarily reproduce?

Most prokaryotes divide by binary fission.

What is horizontal gene transfer in prokaryotes?

It is a method of genetic recombination that does not involve sexual reproduction.

What are the basic shapes of prokaryotic cells?

Rod (bacillus), spherical (coccus), and spiral or helical (spirillium).

What is a significant difference in the plasma membranes of Archaea compared to Bacteria?

Archaean membranes are formed on a glycerol skeleton with ether linkages, while bacterial membranes use ester bonds.

What type of photosynthesis can prokaryotes perform?

Prokaryotes can perform oxygenic and anoxygenic photosynthesis.

What are halophiles and thermophiles?

Halophiles are salt-tolerant bacteria, while thermophiles thrive in very hot waters.

What is the role of plasmids in prokaryotic cells?

Plasmids are small DNA molecules that can carry additional genetic information.

How do prokaryotic ribosomes differ from eukaryotic ribosomes?

Prokaryotic ribosomes differ in structure and size from eukaryotic ribosomes.

What is the significance of the Morning Glory pool in Yellowstone National Park?

It is a hot spring where thermophilic prokaryotes thrive, contributing to its vivid blue color.

What is the difference in internal compartmentalization between prokaryotes and eukaryotes?

Prokaryotes have no membrane-bounded organelles or internal compartments.

What is the size comparison of prokaryotic cells to many eukaryotic cells?

Prokaryotic cells are much smaller, typically between 0.5-5 µm compared to 10-100 µm for eukaryotic cells.

What is the metabolic diversity of prokaryotes?

Prokaryotes can utilize energy from inorganic molecules and perform various metabolic processes.

What are the four key areas in which Bacteria and Archaea differ?

Plasma membranes, cell walls, DNA replication, and gene expression.

What is the significance of the tetraether polymer in Archaea?

It allows extremophiles to withstand high temperatures.

What is a key difference in the cell wall composition between Archaea and Bacteria?

Bacteria have peptidoglycan in their cell walls, while Archaea lack peptidoglycan.

How is DNA replication in Archaea similar to that in eukaryotes?

Archaeal DNA replication is more similar to that of eukaryotes than to Bacteria.

What are the three basic shapes of prokaryotes?

Cocci (spherical), bacilli (rod-shaped), and spirilli (spiral-shaped).

What is the function of the nucleoid in prokaryotic cells?

The nucleoid is the location of the bacterial chromosome.

What role do ribosomes play in prokaryotic cells?

Ribosomes are the site of protein synthesis.

What is the function of the plasma membrane in prokaryotic cells?

The plasma membrane regulates the entrance and exit of molecules.

What is the purpose of fimbriae in prokaryotic cells?

Fimbriae are hairlike bristles that allow adhesion to surfaces.

What is the function of the flagellum in prokaryotic cells?

The flagellum is a rotating filament that pushes the cell forward.

What is the role of the capsule in prokaryotic cells?

The capsule is a gel-like coating outside the cell wall that provides protection.

How do Gram-positive and Gram-negative bacteria differ in their cell wall structure?

Gram-positive bacteria have a thicker peptidoglycan wall and stain purple, while Gram-negative bacteria have less peptidoglycan and stain pink.

What is the significance of plasmids in prokaryotic cells?

Plasmids are accessory rings of DNA that usually contain extra information such as antibiotic resistance genes.

What are the three types of horizontal gene transfer in prokaryotes?

Transformation, transduction, and conjugation.

What occurs during transformation in prokaryotic genetics?

The cell takes up prokaryotic DNA directly from the environment.

What is the typical method of reproduction for prokaryotes?

Prokaryotes reproduce by binary fission.

What is the difference in ribosome size between prokaryotes and eukaryotes?

Prokaryotic ribosomes are smaller than those of eukaryotes.

What is the function of the cell wall in prokaryotic cells?

The cell wall provides structure, support, and protection.

How do Archaean cell walls differ from bacterial cell walls?

Archaean cell walls contain polysaccharides and proteins but lack peptidoglycan.

What is the significance of the Gram stain in microbiology?

The Gram stain is used to classify bacteria based on the thickness of their cell walls.

What is the typical chromosome structure in most bacteria?

Most bacteria have a single circular chromosome located in the nucleoid region.

What are virulence factors in the context of plasmids?

Virulence factors are genes found on plasmids that contribute to a bacterium's ability to cause disease.

What is the significance of antibiotic resistance genes in plasmids?

Antibiotic resistance genes allow bacteria to survive in the presence of antibiotics.

What is the role of the capsule in protecting prokaryotic cells?

The capsule provides protection from the immune system and the environment.

What is transduction in bacteria?

Transduction is the process where a bacteriophage injects DNA into a cell, containing a small fragment of DNA from a different prokaryote.

How does conjugation occur in bacteria?

Conjugation involves the transfer of DNA from one cell to another via a pilus that physically connects the two cells.

What is horizontal gene transfer?

Horizontal gene transfer is the movement of genes among individuals from different species, often involving mechanisms such as transduction, conjugation, and transformation.

What role do mutations play in bacterial populations?

Mutations can arise spontaneously and can be increased by radiation and chemicals, spreading rapidly through mechanisms like horizontal gene transfer.

What are virulence plasmids?

Virulence plasmids are plasmids that often code for non-essential but advantageous genes, such as antibiotic resistance or metabolic pathways.

What is natural transformation in bacteria?

Natural transformation occurs when DNA released from a dead cell is picked up by a live cell, facilitated by proteins encoded by the bacterial chromosome.

What is the F plasmid in E. coli?

The F plasmid, or fertility factor, is required for conjugation in E. coli, where F+ cells contain the plasmid and F- cells do not.

What is the significance of endospores in bacteria?

Endospores allow some bacteria to survive harsh conditions, serving as a survival mechanism rather than a reproductive strategy.

What are the two major groups of prokaryotes?

The two major groups of prokaryotes are Gram-positive and Gram-negative bacteria.

How does the Gram stain procedure differentiate bacteria?

The Gram stain procedure differentiates bacteria based on cell wall composition: Gram-positive bacteria have a thick peptidoglycan layer and stain purple, while Gram-negative bacteria have a thin layer and stain pink.

What is Bergey's Manual of Systematic Bacteriology?

Bergey's Manual is a classification system for prokaryotes, with three of five volumes completed, based on molecular data.

What is the structure of Gram-positive bacteria?

Gram-positive bacteria have a thick layer of peptidoglycan in their cell wall.

What is the structure of Gram-negative bacteria?

Gram-negative bacteria have a thin layer of peptidoglycan and may have an outer membrane.

What happens to the crystal violet stain in Gram-positive bacteria?

In Gram-positive bacteria, the crystal violet stain is trapped by the thick peptidoglycan layer.

What happens to the crystal violet stain in Gram-negative bacteria?

In Gram-negative bacteria, the crystal violet stain is easily rinsed away, revealing a red dye.

What is the significance of large-scale sequencing in bacterial classification?

Large-scale sequencing indicates that the vast majority of bacteria have never been cultured or studied in detail, complicating official classification.

What is the role of plasmids in bacterial cells?

Plasmids may encode advantageous information but are not required for normal bacterial function.

What is the outcome of bacterial recombination?

Bacterial recombination can result in recombinant cells with new genetic combinations.

What are some examples of advantageous genes carried by plasmids?

Examples include genes for antibiotic resistance and metabolic pathways for fermenting new sugars.

What is the purpose of artificial transformation in the lab?

Artificial transformation is used to introduce foreign DNA into bacterial cells for research and genetic engineering.

What are the implications of mutations in bacterial populations?

Mutations can lead to rapid changes in bacterial populations, including the emergence of antibiotic resistance.

What are the two main types of bacteria based on Gram staining?

Gram-positive and Gram-negative bacteria.

What is the structure that provides rigidity to the bacterial cell wall?

Peptidoglycan layer.

What type of bacteria is Bacillus anthracis and what disease does it cause?

Gram-positive bacillus; it causes anthrax.

Name a Gram-negative bacterium that causes diarrhea.

Escherichia coli.

What is a common characteristic of Gram-negative bacteria?

They have an outer membrane and a thinner peptidoglycan layer compared to Gram-positive bacteria.

What type of bacteria is Staphylococcus aureus and what conditions can it cause?

Gram-positive coccus; it can cause conditions ranging from impetigo to necrotizing fasciitis.

What are heterocysts in cyanobacteria?

Specialized cells that fix nitrogen and exchange metabolic products with photosynthetic cells.

What is the role of prokaryotes in ecosystems?

They recycle chemical elements and function as decomposers.

What are methanogens and where do they typically live?

They are archaea that produce methane as a waste product and live in swamps and marshes.

What is bioremediation?

The use of bacteria to remove pollutants from water, air, and soil.

What is a significant product derived from the use of prokaryotes in biotechnology?

Cheese, wine, beer, bread, and yogurt.

What is the significance of the Gram stain in relation to antibiotics?

It can indicate the likelihood of being susceptible to antibiotics that target cell wall synthesis or integrity.

What type of metabolism do most bacteria exhibit?

Most are heterotrophic, requiring an outside source of organic compounds.

What is the difference between chemoautotrophs and photoautotrophs?

Chemoautotrophs extract energy from inorganic molecules, while photoautotrophs obtain energy from solar light.

What are extremophiles?

Archaea that live in extreme environments, such as extreme halophiles and extreme thermophiles.

What is the role of Rhizobium in mutualism?

It forms root nodules in legumes and fixes atmospheric nitrogen.

What is a pathogenic bacterium?

A bacterium that can produce disease, often possessing extra genes coding for virulence factors.

How can genes be transferred between bacteria?

Through mechanisms such as horizontal gene transfer.

What is the impact of E. coli O157:H7 on human health?

It can produce a toxin that damages the intestinal lining, causing bloody diarrhea.

What is the function of biostimulation in bioremediation?

It adds nutrients to encourage the growth of naturally occurring microbes.

What is the significance of bacterial 'headlights' in Photoblepharon palpebratum?

They are specialized organs that harbor bioluminescent bacteria for attracting prey and signaling mates.

What is the typical size of bacteria?

Most bacteria are around 1-10 micrometers in size.

What is the role of prokaryotes in carbon cycling?

They continuously move carbon through the biosphere.