Download presentation
Published byJuliet Holland Modified over 9 years ago
1
Domain (Kingdom) Bacteria, Domain (Kingdom) Archaea, and Viruses
Chapter 14 Lecture Outline Domain (Kingdom) Bacteria, Domain (Kingdom) Archaea, and Viruses Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
2
Outline Introduction Features of Kingdoms (Domains) Bacteria and Archaea Domain Bacteria (Kingdom Bacteria) – The True Bacteria Human Relevance of the Unpigmented Purple, and Green Sulfur Bacteria Class Cyanobacteriae – The Cyanobacteria (Blue-Green Bacteria) Class Prochlorobacteriae – The Prochlorobacteria Kingdom Archaea (Domain Archaea) – The Archaebacteria Viruses Viroids and Prions
3
Introduction Fossils of bacteria - 3.5 billion years old
Fossils of first eukaryotic cells billion years old Bacteria found in astronomical numbers today. Approximately 10 million to 1 billion Much debate as to method of classification
4
Features of Kingdoms (Domains) Bacteria and Archaea
All have prokaryotic cells. No nuclear envelopes Have long circular strand of DNA, ribosomes, membranes and plasmids No membrane-bound organelles, such as plastids, mitochondria, dictyosomes, endoplasmic reticulum Section of Prochloron cell
5
Features of Kingdoms (Domains) Bacteria and Archaea
Nutrition: Primarily by absorption of food in solution through cell wall Some by chemical reactions or by photosynthesis Reproduction predominately asexual, by fission. Fission - No mitosis, DNA strand duplicates and is distributed to new cells. No sexual reproduction Genetic recombination facilitated by pili or by close contact of cells.
6
Nucleoid - Single chromosome in form of ring
Features of Kingdoms (Domains) Bacteria and Archaea Cellular Detail and Reproduction of Bacteria Folds of plasma and other membranes perform some of functions of organelles in eukaryotic cells. Ribosomes present, but about half the size as those of eukaryotic cells. Nucleoid - Single chromosome in form of ring 30 or 40 plasmids may be present. Plasmids - Small circular DNA molecules that replicate independently of chromosome Entire complement of plasmids consists of multiple copies of one or few different DNA molecules.
7
Replication of nucleoid
Features of Kingdoms (Domains) Bacteria and Archaea Cellular Detail and Reproduction of Bacteria Mitosis does not occur. Fission: The two copies of duplicated chromosomes migrate to opposite ends of cell. Perpendicular walls and cell membranes formed in middle of cell. The 2 new cells separate and enlarge to original size. Replication of nucleoid
8
New wall growing inward of dividing bacterial cell
Features of Kingdoms (Domains) Bacteria and Archaea Cellular Detail and Reproduction of Bacteria Fission: May undergo fission every minutes under ideal conditions Usually exhaust food supplies and accumulate wastes New wall growing inward of dividing bacterial cell
9
Do not produce gametes or zygotes, and do not undergo meiosis
Features of Kingdoms (Domains) Bacteria and Archaea Cellular Detail and Reproduction of Bacteria Do not produce gametes or zygotes, and do not undergo meiosis Three Forms of Genetic Recombination: Conjugation DNA transferred from donor cell to recipient cell usually through pilus (pleural: pili). Transformation Living cell acquires DNA fragments released by dead cells. Transduction DNA fragments carried from one cell to another by viruses. Conjugation
10
Most bacteria less than 2 or 3 micrometers in diameter.
Features of Kingdoms (Domains) Bacteria and Archaea Size, Form, and Classification of Bacteria Most bacteria less than 2 or 3 micrometers in diameter. Occur primarily in three forms: New pictures to be added Spirilla Helix or spiral Cocci Spherical or elliptical Bacilli Rod-shaped or cylindrical
11
Features of Kingdoms (Domains) Bacteria and Archaea Size, Form, and Classification of Bacteria
Also classified by: Presence of sheath around cells, of hair-like or bud-like appendages, of endospores, of pili or of flagella Color Mechanisms of movement Biochemical characteristics Reaction of cell walls to dye Gram-negative Gram-positive
12
Domain Bacteria (Kingdom Bacteria) – The True Bacteria
True bacteria have muramic acid in cell walls, and are different from archaebacteria in their RNA bases, metabolism and lipids. Phylum Bacteriophyta Class Bacteriae - Unpigmented, purple, and green sulfur bacteria Most heterotrophic - Cannot synthesize own food Majority saprobes - Food from nonliving organic matter Responsible for decay and recycling of organic matter in soil Some parasites - Depend on living organisms for food
13
Domain Bacteria (Kingdom Bacteria) – The True Bacteria
Phylum Bacteriophyta Autotrophic bacteria - Synthesize organic compounds from simple inorganic substances Photosynthetic without producing oxygen Purple sulfur bacteria - Bacteriochlorophyll pigments, use hydrogen sulfide Purple nonsulfur bacteria - Bacteriochlorophyll pigments, use hydrogen Green sulfur bacteria - Chlorobium chlorophyll pigments, use hydrogen sulfide Photosynthetic and produce oxygen - Cyanobacteria and chloroxybacteria
14
Domain Bacteria (Kingdom Bacteria) – The True Bacteria
Phylum Bacteriophyta Autotrophic bacteria Chemotrophic bacteria - Obtain energy from various compounds or elements through oxidation Iron bacteria - Transform soluble iron to insoluble Sulfur bacteria - Convert hydrogen sulfide gas to sulfur or sulfur to sulfate Hydrogen bacteria - Use molecular hydrogen derived from anaerobic or nitrogen-fixing bacteria
15
Human Relevance of the Unpigmented, Purple, and Green Sulfur Bacteria
Composting and compost: Bacteria decompose organic waste to form compost. True bacteria and disease: Bacteria involved in diseases of plants, animals and humans, and in losses of food Modes of access of disease bacteria: Access from the air Coughs, sneezes - Saliva droplets contain bacteria. Diphtheria, whooping cough, some meningitis forms, pneumonia, strep throat, tuberculosis
16
Human Relevance of the Unpigmented, Purple, and Green Sulfur Bacteria
True bacteria and disease: Modes of access of disease bacteria: Access through contamination of food and drink Food poisoning and diseases associated with natural disasters Cholera, dysentery, Staphylococcus and Salmonella food poisoning Legionnaire disease Botulism Escherichia coli
17
Human Relevance of the Unpigmented, Purple, and Green Sulfur Bacteria
True bacteria and disease: Modes of access of disease bacteria: Access through direct contact - Enter through skin or mucus membranes Syphilis, Gonorrhea, Chlamydia, anthrax, brucellosis Access through wounds Tetanus and gas gangrene Access through bites of insects and other organisms Bubonic plague, tularemia, rickettsias, mycoplasmas, Lyme disease
18
Human Relevance of the Unpigmented, Purple, and Green Sulfur Bacteria
Koch’s postulates - Rules for proving a particular microorganism is cause of a particular disease Microorganism must be present in all cases of disease. Microorganism must be isolated from victim in pure culture. Microorganisms from pure culture must be able to infect hosts. Microorganism must be isolated from experimentally-infected host and grown in pure culture for comparison with original culture.
19
Human Relevance of the Unpigmented, Purple, and Green Sulfur Bacteria
True bacteria useful to humans: Biological control organisms Bacillus thuringiensis - Effective against caterpillars and worms Multiplies in digestive tract and paralyzes gut Bacillus popilliae - Effective against Japanese beetle grubs Bioremediation - Use of living organisms in cleanup of toxic waste and pollution Affect of Bacillus thuringiensis on tomato hornworm
20
Human Relevance of the Unpigmented, Purple, and Green Sulfur Bacteria
True bacteria useful to humans: Other useful bacteria Human health - Lactobacillus acidophilus Aids in digestion Used for elimination of yeast infections Dairy - Buttermilk, sour cream, yogurt, cheese Industrial - Utilizes bacteria waste products Solvents, explosives, ascorbic acid (vitamin C), citric acid
21
Class Cyanobacteriae – The Cyanobacteria (Blue-Green Bacteria)
Distinctions between traditional bacteria and cyanobacteria: Cyanobacteria have chlorophyll a and oxygen is produced from photosynthesis. Cyanobacteria contain phycobilins. Cyanobacteria can both fix nitrogen and produce oxygen.
22
Class Cyanobacteriae – The Cyanobacteria (Blue-Green Bacteria)
Distribution - In diverse variety of habitats Pools and ditches, particularly if polluted Fresh and marine water, but not acidic water Principal photosynthetic organisms in plankton Waters of various temperatures - Hot springs at Yellowstone National Park Often first photosynthetic organisms after volcanic eruption Symbiotic with other organisms Yellowstone Amoebae, sea anemones, fungi (producing lichens), cycads
23
Class Cyanobacteriae – The Cyanobacteria (Blue-Green Bacteria)
Form, metabolism, and reproduction: Often in chains, or colonies held together by gelatinous sheaths Cells blue-green in color in about half of the approximately 1,500 species. Produce nitrogenous food reserve - Cyanophycin Flagella unknown
24
Class Cyanobacteriae – The Cyanobacteria (Blue-Green Bacteria)
Form, metabolism, and reproduction: New cells by fission, or by fragmentation of colonies or filaments. In Nostoc and Anabaena, fragmentation often occurs at heterocyst. Heterocyst - Large colorless, nitrogen-fixing cell Also produce akinetes Akinetes - Thick-walled cells that resist adverse conditions
25
Class Cyanobacteriae – The Cyanobacteria (Blue-Green Bacteria)
Cyanobacteria, chloroplasts, and oxygen Thought that chloroplasts originated as cyanobacteria or prochlorobacteria living within other cells. Fossils of cyanobacteria, 3.5 billion years old, found in Australia. 3 billion years ago, cyanobacteria produced oxygen as by- product of photosynthesis. Oxygen accumulated in atmosphere, becoming substantial 1 billion years ago. As oxygen accumulated, other photosynthetic organisms appeared and forms of aerobic respiration developed. In last half billion years enough ozone for UV shield and for photosynthetic organisms to survive on land.
26
Class Cyanobacteriae – The Cyanobacteria (Blue-Green Bacteria)
Human relevance of the cyanobacteria: Cyanobacteria are among the many aquatic and photosynthetic organisms at the bottom of various food chains. Often become abundant in bodies of fresh water in warmer months Algal blooms Can be poisonous to livestock Food - Spirulina with significant vitamin content Swimmers itch Nitrogen fixation
27
Class Prochlorobacteriae – The Prochlorobacteria
Have chlorophylls a and b of higher plants, but no phycobilin accessory pigments like cyanobacteria Adds to theory that chloroplasts originated from cells living within cells of other organisms Cell structure and chemistry similar to those of cyanobacteria and other true bacteria. Prochloron
28
Kingdom Archaea (Domain Archaea) – The Archaebacteria
Metabolism is fundamentally different from other lines of bacteria. Differ from true bacteria by unique sequences of bases in RNA, by lack of muramic acid in walls, and by production of distinct lipids Methane bacteria Killed by oxygen Active only under anaerobic conditions Energy derived from generation of methane gas from carbon dioxide and hydrogen.
29
Kingdom Archaea (Domain Archaea) – The Archaebacteria
Salt bacteria Metabolism enables these bacteria to thrive under extreme salinity. Carry out simple photosynthesis with aid of bacterial rhodopsin. Lake Bonneville, Utah with very high salt content
30
Kingdom Archaea (Domain Archaea) – The Archaebacteria
Sulfolobus bacteria Occur in sulfur hot springs Metabolism allows these species to thrive at very high temperatures. Mostly in vicinity of 80oC (170oF), some even higher Shape of ribosomes and chemistry of sulfolobus bacteria distinguishes them from other archaebacteria, true bacteria and eukaryotes.
31
Kingdom Archaea (Domain Archaea) – The Archaebacteria
Human relevance of the archaebacteria: Methane bacteria produce methane gas as they digest organic wastes in absence of oxygen. Methane may be used to furnish energy for engines, heating and cooking. Methane has a high octane level and is clean and nonpolluting. Methane produced on large-scale when organic wastes fed into methane digester. Leftover sludge makes excellent fertilizer.
32
Papavoviruses in a human wart
Size and structure: Represent interface between biochemistry and life Lack cytoplasm or cellular structure Do not grow by increasing in size or dividing Do not respond to external stimuli Cannot move on their own Cannot carry on independent metabolism Inside living cells, they express their genes and use cellular machinery to produce more virus particles. Papavoviruses in a human wart About size of large molecules, nanometers
33
Viruses Size and structure:
Consist of nucleic acid core surrounded by protein coat. Architecture of protein coat varies. 20-sided, or head and tail Core consists of DNA or RNA, not both. Classified according to DNA or RNA. Then according to size and shape, nature of protein coats, and number of identical structural units in their cores. Replace with new photo Bacteriophages - Viruses that attack bacteria
34
Bacteriophage replication
Viruses Viral reproduction: Viruses replicate at expense of their host cells. Attach to susceptible cell Penetrate to cell interior DNA or RNA dictates synthesis of new molecules. New viruses released from host cell. Host cell dies. Some can mutate very rapidly. As a result, new vaccines need to be developed. Bacteriophage replication
35
Viruses Human relevance of viruses:
Annual loss in work time due to common cold and influenza viruses alone amount to millions of hours. Immunizations have dramatically decreased incidence of many viral diseases such as chicken pox, German measles, and mumps. AIDS Retrovirus - A virus with two identical nuclear strands Evolves extremely quickly About a million times faster than cellular organisms Used to infect disease organisms of animals and plants Ticks, insects, possibly gypsy moths
36
Viroids and Prions Viroids - Circular strands of RNA that occur in nuclei of infected plant cells Transmitted from plant to plant via pollen, ovules, or machinery Cause more than a dozen plant diseases Prions - Appear to be particles of protein that cause diseases of animals and humans Believed to cause disease by inducing abnormal folding of proteins in brain, resulting in brain damage Cruetzfeldt-Jacob disease
37
Review Introduction Features of Kingdoms (Domains) Bacteria and Archaea Domain Bacteria (Kingdom Bacteria) – The True Bacteria Human Relevance of the Unpigmented Purple, and Green Sulfur Bacteria Class Cyanobacteriae – The Cyanobacteria (Blue-Green Bacteria) Class Prochlorobacteriae – The Prochlorobacteria Kingdom Archaea (Domain Archaea) – The Archaebacteria Viruses Viroids and Prions
Similar presentations
© 2025 SlidePlayer.com Inc.
All rights reserved.