Presentation on theme: "Chapter 23 Table of Contents Section 1 Prokaryotes"— Presentation transcript:
1Chapter 23 Table of Contents Section 1 Prokaryotes BacteriaTable of ContentsSection 1 ProkaryotesSection 2 Biology of ProkaryotesSection 3 Bacteria and Humans
2Section 1 ProkaryotesChapter 23ObjectivesExplain the phylogenetic relationships between the domains Archaea, Bacteria, and Eukarya.Identify three habitats of archaea.Describe the common methods used to identify bacteria.Identify five groups of bacteria.Explain the importance of nitrogen-fixing bacteria for many of Earth’s ecosystem.
3Two Major Domains: Archaea and Bacteria Section 1 ProkaryotesChapter 23Two Major Domains: Archaea and BacteriaProkaryotes 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 genetic traits, their modes of nutrition, and their habitats.Based on genetic differences, prokaryotes are grouped in two domains: Domain Archaea and Domain Bacteria.
4Three Domains of Living Organisms Section 1 ProkaryotesChapter 23Three Domains of Living Organisms
5Chapter 23 Domain Archaea Section 1 ProkaryotesChapter 23Domain ArchaeaOne of the ways in which archaea differ is the make up of their cell wall. Archaeal cells walls do not contain peptidoglycan.Peptidoglycan is a protein-carbohydrate complex found in bacterial cell walls that make their cells walls rigid.Archaea differ in the types of lipids in their cell membrane. Also, archaeal genes do not contain introns.
6Domain Archaea, continued Section 1 ProkaryotesChapter 23Domain Archaea, continuedArchaeal GroupsArchaeal groups include methanogens, halophiles, and thermoacidophiles.Methanogens convert hydrogen gas and carbon dioxide into methane. They can be found in the intestines of organisms such as cattle and termites.
7Domain Archaea, continued Section 1 ProkaryotesChapter 23Domain Archaea, continuedArchaeal Groups, continuedHalophiles are “salt-loving” archaea that live in very salty environments such as the Great Salt Lake and the Dead Sea.Thermoacidophiles 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.
8Chapter 23 Domain Bacteria Section 1 ProkaryotesChapter 23Domain BacteriaBacteria 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 bacilli (singular, bacillus). An example of bacilli is Escherichia coli.Sphere-shaped bacteria are called cocci (singular, coccus). An example of cocci is Micrococcus luteus.
9Domain Bacteria, continued Section 1 ProkaryotesChapter 23Domain Bacteria, continuedSpiral shaped bacteria are called spirilla (singular, spirillum). An example of spirilla bacteria includes Spirillum volutans.Cocci that form chains similar to a string of beads are called streptococci.Cocci that form clusters similar to a bunch of grapes are called staphylococci.
11Characteristics of Bacteria Section 1 ProkaryotesChapter 23Characteristics of BacteriaClick below to watch the Visual Concept.Visual Concept
12Domain Bacteria, continued Section 1 ProkaryotesChapter 23Domain Bacteria, continuedGram StainMost 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 thick layer of peptidoglycan in their cell wall, and they appear purple under a microscope after the Gram-staining procedure.Gram-negative bacteria have a thin layer of peptidoglycan in their cell wall, and they appear reddish-pink under a microscope after the Gram-staining procedure.
14Chapter 23 Gram Stain Section 1 Prokaryotes Click below to watch the Visual Concept.Visual Concept
15Important Bacterial Groups Section 1 ProkaryotesChapter 23Important Bacterial GroupsBacteria are also classified by their biochemical properties and evolutionary relationships.ProteobacteriaProteobacteria 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 Rhizobium, the genus Agrobacterium, and the bacterium Escherichia coli.
16Important Bacterial Groups, continued Section 1 ProkaryotesChapter 23Important Bacterial Groups, continuedGram-Positive BacteriaNot all of the bacteria in this group are Gram-positive. Biologists place a few species of Gram-negative bacteria in this group because these species are genetically similar to Gram-positive bacteria.Members of this group include the streptococcal species, Clostridium botulinum, Bacillus anthracis, and members of the genus Mycobacteria.
17Important Bacterial Groups, continued Section 1 ProkaryotesChapter 23Important Bacterial Groups, continuedGram-Positive Bacteria, continuedActinomycetes are Gram-positive bacteria, some species of which produce antibiotics.Antibiotics are chemicals that inhibit the growth of or kill other microorganisms. Streptomycin and tetracycline are examples of antibiotics that are used medicinally.
18Important Bacterial Groups, continued Section 1 ProkaryotesChapter 23Important Bacterial Groups, continuedCyanobacteriaCyanobacteria use photosynthesis 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 lack a membrane-bound nucleus and chloroplasts.
19Important Bacterial Groups, continued Section 1 ProkaryotesChapter 23Important Bacterial Groups, continuedSpirochetesSpirochetes 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.
20Important Bacterial Groups, continued Section 1 ProkaryotesChapter 23Important Bacterial Groups, continuedChlamydiaGram-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 sexually transmitted infection called chlamydia.
21Section 2 Biology of Prokaryotes Chapter 23ObjectivesDescribe the internal and external structure of prokaryotic cells.Identify the need for endospores.Compare four ways in which prokaryotes get energy and carbon.Identify the different types of environments in which prokaryotes can live.List three types of genetic recombination that prokaryotes use.
22Structure and Function Section 2 Biology of ProkaryotesChapter 23Structure and FunctionThe major structures of a prokaryotic cell include a cell wall, a cell membrane, cytoplasm, ribosomes, and sometimes a capsule, pili, endospores, and flagella.Cell WallMost prokaryotes have a cell wall. Bacterial cell walls contain peptidoglycan. Archaeal cell walls do not have peptidoglycan; instead, some contain pseudomurein, a compound made of unusual lipids and amino acids.
23Structure and Function, continued Section 2 Biology of ProkaryotesChapter 23Structure and Function, continuedCell Membrane and CytoplasmBacterial 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.
24Structure and Function, continued Section 2 Biology of ProkaryotesChapter 23Structure and Function, continuedDNAProkaryotic DNA is a single closed loop of double-stranded DNA attached at one point to the cell membrane.Along with a single main chromosome, some prokaryotes have plasmids, which are small, circular, self-replicating loops of double-stranded DNA.
25Structure and Function, continued Section 2 Biology of ProkaryotesChapter 23Structure and Function, continuedCapsules and PiliMany bacteria have an outer covering of polysaccharides called a capsule that protects the cell against drying, pathogens, or harsh chemicals.Pili 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.
26Chapter 23 Bacterial Capsule Section 2 Biology of Prokaryotes Click below to watch the Visual Concept.Visual Concept
27Chapter 23 Pilus Section 2 Biology of Prokaryotes Click below to watch the Visual Concept.Visual Concept
28Structure and Function, continued Section 2 Biology of ProkaryotesChapter 23Structure and Function, continuedEndosporesSome Gram-positive bacteria can form a thick-coated, resistant structure called an endospore when environmental conditions become harsh.
29Structure and Function, continued Section 2 Biology of ProkaryotesChapter 23Structure and Function, continuedProkaryotic MovementMany prokaryotes have long flagella that allow the prokaryotes to move toward food sources or away from danger.
30Structural Characteristics of a Bacterial Cell Section 2 Biology of ProkaryotesChapter 23Structural Characteristics of a Bacterial Cell
31Parts of a Prokaryotic Cell Section 2 Biology of ProkaryotesChapter 23Parts of a Prokaryotic CellClick below to watch the Visual Concept.Visual Concept
32Nutrition and Metabolism Section 2 Biology of ProkaryotesChapter 23Nutrition and MetabolismProkaryotes obtain nutrients either from the nonliving environment or by utilizing the products or bodies of living organisms.Heterotrophs obtain carbon from other organisms.Autotrophs obtain their carbon from CO2.Chemotrophs get energy from chemicals in the environment.
33Chapter 23 Prokaryotic Habitats Section 2 Biology of ProkaryotesChapter 23Prokaryotic HabitatsDifferent prokaryotic species live in different environments.Temperature requirements range from 0°C to 110°C.Most prokaryotic species grow best at a neutral pH.
34Reproduction and Recombination Section 2 Biology of ProkaryotesChapter 23Reproduction and RecombinationGenetic recombination in bacteria can occur by the following three ways:transformation (taking in DNA from the outside environment)conjugation (exchanging DNA with other bacteria via pili)transduction (transmission of bacterial DNA via viruses).
35Chapter 23 Objectives Section 3 Bacteria and Humans Describe the ways in which bacteria can cause disease in humans.Explain how a bacterial population can develop resistance to antibiotics.Identify reasons for recent increases in the numbers of certain bacterial infectious diseases.Identify ways of preventing a foodborne illness at home.List four industrial uses of bacteria.
36Chapter 23 Bacteria and Health Section 3 Bacteria and HumansChapter 23Bacteria and HealthHuman diseases may result from endotoxins or exotoxins produced by bacteria or from the destruction of body tissues.
37Bacteria and Health, continued Section 3 Bacteria and HumansChapter 23Bacteria and Health, continuedAntibiotics and Antibiotic ResistanceA mutation in the DNA of a single bacterium can confer resistance to an antibiotic.Cells with the mutant gene have a selective advantage when the antibiotic is present.Mutant cells take over the population when the normal cells die.
38Bacteria and Health, continued Section 3 Bacteria and HumansChapter 23Bacteria and Health, continuedEmerging Infectious Diseases Caused by BacteriaThe 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.
39Bacteria and Health, continued Section 3 Bacteria and HumansChapter 23Bacteria and Health, continuedFood Hygiene and BacteriaFoodborne illnesses can be avoided by selecting, storing, cooking, and handling food properly.Frequent hand washing in hot, soapy water is also very important.
41Chapter 23 Bacteria in Industry Section 3 Bacteria and HumansChapter 23Bacteria in IndustryMany 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 bioremediation, which uses bacteria to break down pollutants.
42Chapter 23 Bacteria and Food Section 3 Bacteria and Humans Click below to watch the Visual Concept.Visual Concept