Section 1 Prokaryotes Chapter 23 Objectives • Explainthe phylogenetic relationships between the domains Archaea, Bacteria, and Eukarya. • Identifythree habitats of archaea. • Describethe common methods used to identify bacteria. • Identifyfive groups of bacteria. • Explainthe importance of nitrogen-fixing bacteria for many of Earth’s ecosystem.

Section 1 Prokaryotes Chapter 23 Two Major Domains: Archaea and Bacteria • _____________________ are single-celled organisms that do not have a membrane-bound nucleus, and can live in nearly every environment on Earth. • Although tiny, prokaryotes differ greatly in their • Based on genetic differences, prokaryotes are grouped in two domains: Domain ______________ and Domain ___________________.

Section 1 Prokaryotes Chapter 23 Three Domains of Living Organisms

Section 1 Prokaryotes Chapter 23 Domain Archaea • One of the ways in which archaea differ is the make up of their ___________________. Archaeal cells walls do not contain ____________________. • ________________________is a protein-carbohydrate complex found in bacterial cell walls that make their cells walls rigid. • Archaea differ in the types of _______________ in their cell membrane. Also, archaea genes do not contain ________________________.

Section 1 Prokaryotes Chapter 23 Domain Archaea, continued • Archaeal Groups • Archaeal groups include methanogens, halophiles, and thermoacidophiles. • Methanogens convert _______________________ and _________________ into methane. They can be found in the

Section 1 Prokaryotes Chapter 23 Domain Archaea, continued • Archaeal Groups,continued • _____________________ are “salt-loving” archaea that live in very salty environments such as the Great Salt Lake and the Dead Sea. • ___________________________ live in very hot, acidic environments, such as the hot springs of Yellowstone National Park. Some thermoacidophiles live at temperatures up to 110°C (230°F) and at a pH of less than 2.

Section 1 Prokaryotes Chapter 23 Domain Bacteria • Bacteria occur in many shapes and sizes. Most bacteria have one of three basic shapes: rod-shaped, sphere-shaped, or spiral-shaped. • Rod-shaped bacteria are called ____________ (singular, bacillus). An example • Sphere-shaped bacteria are called ___________ (singular, coccus). An example of

Section 1 Prokaryotes Chapter 23 Domain Bacteria, continued • Spiral shaped bacteria are called _______________ (singular, spirillum). An example of • Cocci that form chains similar to a string of beads are called ___________________________. • Cocci that form clusters similar to a bunch of grapes are called _________________________.

Section 1 Prokaryotes Chapter 23 Three Bacterial Cell Shapes

Section 1 Prokaryotes Chapter 23 Domain Bacteria, continued • Gram Stain • Most species of bacteria are classified into two categories based on the structure of their cell walls as determined by a technique called the Gram stain. • Gram-positive bacteria have a _____________ layer of peptidoglycan in their cell wall, and they appear • Gram-negative bacteria have a ______________ layer of peptidoglycan in their cell wall, and they appear

Section 1 Prokaryotes Chapter 23 Gram Staining

Section 1 Prokaryotes Chapter 23 Important Bacterial Groups • Bacteria are also classified by their biochemical properties and evolutionary relationships. • Proteobacteria • Proteobacteria are one of the largest and most diverse groups of bacteria, and contain several subgroups that are extremely diverse. • Members of this group include bacteria of the genus _________________, the genus ________________, and the bacterium ___________________________.

Section 1 Prokaryotes Chapter 23 Important Bacterial Groups, continued • Gram-Positive Bacteria • Not all of the bacteria in this group are Gram-positive. Biologists place a few species of Gram-negative bacteria in this group because • Members of this group include the streptococcal species, Clostridium botulinum, Bacillus anthracis, and members of the genus Mycobacteria.

Section 1 Prokaryotes Chapter 23 Important Bacterial Groups, continued • Gram-Positive Bacteria,continued • Actinomycetes are Gram-positive bacteria, some species of which produce ___________________. • ___________________________ are chemicals that inhibit the growth of or kill other microorganisms. Streptomycin and tetracycline are examples of antibiotics that are used medicinally.

Section 1 Prokaryotes Chapter 23 Important Bacterial Groups, continued • Cyanobacteria • Cyanobacteria use _____________________ to get energy from sunlight, and make carbohydrates from water and carbon dioxide. During this process, they create oxygen as a waste product. • Once called blue-green algae, cyanobacteria are now known to be bacteria because they

Section 1 Prokaryotes Chapter 23 Important Bacterial Groups, continued • Spirochetes • Spirochetes are Gram-negative, spiral-shaped bacteria that move by means of a corkscrew-like rotation. Some are aerobic. • Spirochetes can live freely or as pathogens. Pathogenic spirochetes include Treponema pallidum, the causative agent of syphilis, and Borrelia burgdorferi, which causes Lyme disease.

Section 1 Prokaryotes Chapter 23 Important Bacterial Groups, continued • Chlamydia • Gram-negative coccoid pathogens of the group Chlamydia live only inside animal cells. The cell walls of chlamydia do not have peptidoglycan. Chlamydia trachomatis causes the ____________________________ infection called chlamydia.

Section 2 Biology of Prokaryotes Chapter 23 Objectives • Describethe internal and external structure of prokaryotic cells. • Identifythe need for endospores. • Comparefour ways in which prokaryotes get energy and carbon. • Identifythe different types of environments in which prokaryotes can live. • Listthree types of genetic recombination that prokaryotes use.

Section 2 Biology of Prokaryotes Chapter 23 Structure and Function • The major structures of a prokaryotic cell include a • Cell Wall • Most prokaryotes have a cell wall. Bacterial cell walls contain peptidoglycan. Archaeal cell walls do not have peptidoglycan; instead, some contain __________________________, a compound made of unusual lipids and amino acids.

Section 2 Biology of Prokaryotes Chapter 23 Structure and Function, continued • Cell Membrane and Cytoplasm • Bacterial and archaeal cell membranes are lipid bilayers that have proteins. However, the lipids and proteins of archaeal cell walls differ from those of bacterial cell walls. • The cytoplasm is a semifluid solution that contains ribosomes, DNA, small organic and inorganic molecules, and ions.

Section 2 Biology of Prokaryotes Chapter 23 Structure and Function, continued • DNA • Prokaryotic DNA is a • Along with a single main chromosome, some prokaryotes have _________________________, which are small, circular, self-replicating loops of double-stranded DNA.

Section 2 Biology of Prokaryotes Chapter 23 Structure and Function, continued • Capsules and Pili • Many bacteria have an outer covering of polysaccharides called a____________________ thatprotects the cell against drying, pathogens, or harsh chemicals. • _________________ are short, hairlike protein structures on the surface of some bacteria that help bacteria connect to each other and to surfaces, such as those of a host cell.

Section 2 Biology of Prokaryotes Chapter 23 Structure and Function, continued • Endospores • Some Gram-positive bacteria can form a thick-coated, resistant structure called an_____________________when environmental conditions become harsh.

Section 2 Biology of Prokaryotes Chapter 23 Structure and Function, continued • Prokaryotic Movement • Many prokaryotes have long flagella that allow the prokaryotes to move toward food sources or away from danger.

Section 2 Biology of Prokaryotes Chapter 23 Structural Characteristics of a Bacterial Cell

Section 2 Biology of Prokaryotes Chapter 23 Nutrition and Metabolism • Prokaryotes obtain nutrients either from the nonliving environment or by utilizing the products or bodies of living organisms. • Heterotrophs • Autotrophs • Chemotrophs

Section 2 Biology of Prokaryotes Chapter 23 Prokaryotic Habitats • Different prokaryotic species live in different environments. • Temperature requirements range from ______ to __________. • Most prokaryotic species grow best at a

Section 2 Biology of Prokaryotes Chapter 23 Reproduction and Recombination • Genetic recombination in bacteria can occur by the following three ways: • Transformation • conjugation • transduction

Section 3 Bacteria and Humans Chapter 23 Objectives • Describethe ways in which bacteria can cause disease in humans. • Explainhow a bacterial population can develop resistance to antibiotics. • Identifyreasons for recent increases in the numbers of certain bacterial infectious diseases. • Identifyways of preventing a foodborne illness at home. • Listfour industrial uses of bacteria.

Section 3 Bacteria and Humans Chapter 23 Bacteria and Health • Human diseases may result from _____________________ or ___________________produced by bacteria or from the destruction of body tissues.

Section 3 Bacteria and Humans Chapter 23 Bacteria and Health, continued • Antibiotics and Antibiotic Resistance • A _________________ in the DNA of a single bacterium can confer resistance to an antibiotic. • Cells with the ____________ gene have a selective advantage when the antibiotic is present. • ___________________ cells take over the population when the normal cells die.

Section 3 Bacteria and Humans Chapter 23 Bacteria and Health, continued • Emerging Infectious Diseases Caused by Bacteria • The number of certain bacterial diseases has increased because of the increase in the number of antibiotic resistant bacteria, the movement of people into previously untouched areas, and global travel.

Section 3 Bacteria and Humans Chapter 23 Bacteria and Health, continued • Food Hygiene and Bacteria • Foodborne illnesses can be avoided by • Frequent hand washing in hot, soapy water is also very important.

Section 3 Bacteria and Humans Chapter 23 Important Bacterial Diseases

Section 3 Bacteria and Humans Chapter 23 Bacteria in Industry • Many species of bacteria are used to produce and process different foods, to produce industrial chemicals, to mine for minerals, to produce insecticides, and to clean up chemical and oil spills. • Biologists have learned to harness bacteria to recycle compounds in a process called__________________________, which uses bacteria to break down pollutants.

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