We think you have liked this presentation. If you wish to download it, please recommend it to your friends in any social system. Share buttons are a little bit lower. Thank you!
Presentation is loading. Please wait.
Published byFinn Pridemore
Modified about 1 year ago
Chapter 27 Bacteria & Archaea
First Life on Earth Earth’s first organisms were likely prokaryotes Prokaryotes are divided into two domains: archaea and bacteria Members of Domain Archaea are composed of Kingdom Archaeabacteria ; they are found in the harshest environments Members of Domain Bacteria are composed of Kingdom Eubacteria ; they are found everywhere else © 2011 Pearson Education, Inc.
Structural and Functional Adaptations of Prokaryotes Most prokaryotes are unicellular, although some species form colonies Most prokaryotic cells are 0.5–5 µm, much smaller than the 10–100 µm of many eukaryotic cells Prokaryotic cells have a variety of shapes The three most common shapes are spheres ( cocci ), rods ( bacilli ), and spirals ( spirilli ) © 2011 Pearson Education, Inc.
Figure 27.2 (a) Spherical(b) Rod-shaped(c) Spiral 1 m 3 m
Cell-Surface Structures An important feature of nearly all prokaryotic cells is their cell wall, which maintains cell shape, protects the cell, and prevents it from bursting in a hypotonic environment Eukaryote cell walls are made of cellulose (plants) or chitin (fungi) Bacterial cell walls contain a network of polysaccharides cross-linked by proteins A polysaccharide or protein layer called a capsule covers many prokaryotes © 2011 Pearson Education, Inc.
Figure 27.4 Bacterial cell wall Bacterial capsule Tonsil cell 200 nm
Motility Many bacteria exhibit taxis, the ability to move toward or away from a stimulus Most bacteria propel themselves by flagella scattered about the surface or concentrated at one or both ends Flagella of bacteria, archaea, and eukaryotes are composed of different proteins and likely evolved independently © 2011 Pearson Education, Inc.
Internal Organization and DNA The prokaryotic genome has less DNA than the eukaryotic genome The chromosome is circular and not surrounded by a membrane; it is located in the nucleoid region Some species of bacteria also have smaller rings of DNA called plasmids © 2011 Pearson Education, Inc.
Reproduction and Adaptation Prokaryotes reproduce quickly by binary fission and can divide every 1–3 hours Key features of prokaryotic reproduction: They are small They reproduce by binary fission They have short generation times © 2011 Pearson Education, Inc.
Many prokaryotes form metabolically inactive endospores, which can remain viable in harsh conditions for centuries Prokaryotes are not “primitive” but are highly evolved Their short generation time allows prokaryotes to evolve quickly For example, adaptive evolution in a bacterial colony was documented in a lab over 8 years © 2011 Pearson Education, Inc.
Genetic Diversity in Prokaryotes Prokaryotes have considerable genetic variation Three factors contribute to this genetic diversity: – Rapid reproduction – Mutation – Genetic recombination © 2011 Pearson Education, Inc.
Genetic Recombination Genetic recombination, the combining of DNA from two sources, contributes to diversity Prokaryotic DNA from different individuals can be brought together by transformation, transduction, and conjugation Movement of genes among individuals from different species is called horizontal gene transfer © 2011 Pearson Education, Inc.
Nutritional and Metabolic Adaptations in Prokaryotes Prokaryotes can be categorized by how they obtain energy and carbon Phototrophs obtain energy from light Chemotrophs obtain energy from chemicals Autotrophs require CO 2 as a carbon source Heterotrophs require an organic nutrient to make organic compounds © 2011 Pearson Education, Inc.
The Role of Oxygen in Metabolism Prokaryotic metabolism varies with respect to O 2 – Obligate aerobes require O 2 for cellular respiration – Obligate anaerobes are poisoned by O 2 and use fermentation or anaerobic respiration – Facultative anaerobes can survive with or without O 2 © 2011 Pearson Education, Inc.
Metabolic Cooperation Cooperation between prokaryotes allows them to use environmental resources they could not use as individual cells In some prokaryotic species, metabolic cooperation occurs in surface-coating colonies called biofilms © 2011 Pearson Education, Inc.
Molecular systematics in Prokaryotic Phylogeny Until the late 20th century, systematists based prokaryotic taxonomy on phenotypic criteria Applying molecular systematics to the investigation of prokaryotic phylogeny has produced dramatic results Molecular systematics led to the splitting of prokaryotes into bacteria and archaea © 2011 Pearson Education, Inc.
Prokaryotes Roles in the Biosphere Prokaryotes are so important that if they were to disappear the prospects for any other life surviving would be dim Chemoheterotrophic prokaryotes function as decomposers, breaking down dead organisms and waste products The ecological communities of hydrothermal vents depend on chemoautotropic bacteria for energy © 2011 Pearson Education, Inc.
Ecological Interactions Symbiosis is an ecological relationship in which two species live in close contact: a larger host and smaller symbiont Prokaryotes often form symbiotic relationships with larger organisms © 2011 Pearson Education, Inc.
In mutualism, both symbiotic organisms benefit In commensalism, one organism benefits while neither harming nor helping the other in any significant way In parasitism, an organism called a parasite harms but does not kill its host Parasites that cause disease are called pathogens © 2011 Pearson Education, Inc.
Prokaryotes: Beneficial and Harmful Impacts on Humans Prokaryotes cause about half of all human diseases For example, Lyme disease is caused by a bacterium and carried by ticks © 2011 Pearson Education, Inc.
Pathogenic prokaryotes typically cause disease by releasing exotoxins or endotoxins Exotoxins are secreted and cause disease even if the prokaryotes that produce them are not present Endotoxins are released only when bacteria die and their cell walls break down © 2011 Pearson Education, Inc.
Prokaryotes in Research and Technology Experiments using prokaryotes have led to important advances in DNA technology For example, E. coli is used in gene cloning For example, Agrobacterium tumefaciens is used to produce transgenic plants Bacteria can now be used to make natural plastics © 2011 Pearson Education, Inc.
Prokaryotes are the principal agents in bioremediation, the use of organisms to remove pollutants from the environment Bacteria can be engineered to produce vitamins, antibiotics, and hormones Bacteria are also being engineered to produce ethanol from waste biomass © 2011 Pearson Education, Inc.
CHAPTER 27 Bacteria and Archaea. YOU MUST KNOW The key ways in which prokaryotes differ from eukaryotes with respect to: Genome; Membrane bound organelles;
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Bacteria Staphylococcus bacteria in nose.
Utah’s Great Salt Lake can reach a salt concentration of 32% Its pink color comes from living prokaryotes Overview: Masters of Adaptation © 2011 Pearson.
BACTERIA AND ARCHAEA. YOU MUST KNOW… THE KEY WAYS IN WHICH PROKARYOTES DIFFER FROM EUKARYOTES WITH RESPECT TO GENOME, MEMBRANE-BOUND ORGANELLES, SIZE,
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings PowerPoint Lectures for Biology, Seventh Edition Neil Campbell and Jane Reece.
Chapter 27: The Prokaryotes Objectives 1.Learn about the prokaryotic adaptations that make them successful, including the diverse metabolic pathways. 2.Learn.
Chapter 27 l Prokaryotes and the Origins of Metabolic Diversity.
Prokaryotes Structure Function Reproduction Diversity Ecological Impact.
Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings CHAPTER 27 Prokaryotes.
Chapter 27~Prokaryotes and the Origins of Metabolic Diversity.
Prokaryotes Chapter 27. Found wherever there is life; thrive in habitats that are too cold, too hot, too salty, etc. Most live in symbiotic relationships.
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings PowerPoint ® Lecture Presentations for Biology Eighth Edition Neil Campbell.
PROKARTOTES © 2011 Pearson Education, Inc. Prokaryotes thrive almost everywhere, including places too acidic, salty, cold, or hot for most other organisms.
Chapter 27~ Prokaryotes and the Origins of Metabolic Diversity.
Chapter 27 Prokaryotes! Wow!. Some Interesting Info… *The biomass of all the prokaryotes of the world is 10 times that of eukaryotes! *The # of prokaryotes.
Bacteria and Viruses Chapter 19. Introduction Microscopic life covers nearly every square centimeter of Earth. In a single drop of pond water you would.
Prokaryotes They’re almost everywhere. Prokaryotes were the first organism and persist today as the most numerous and pervasive of all living things.
How do bacterial cell walls differ from plant cell walls? Plants – made of cellulose (polysaccharide) Bacteria – made of peptidoglycan Archaea – lack.
Chapter 27: Prokaryotes 1.Where can you find prokaryotes? -EVERYWHERE!! -Domain Bacteria & Archae 2.What do you know about bacterial structure, function.
Chapter 18. Domain Archaea Only one kingdom: Archaebacteria ▪ Cells contain cell walls ▪ Live in extreme environments (hot, acidic, salty, no O 2.
PROKARYOTES. THEY ARE EVERYWHERE The Major Similarities Between the Two Types of Cells (Prokaryote and eukaryote) Are: They both have DNA as their genetic.
Bacteria and Archaea. Prokaryotes Structure, Function, and Reproduction Nutritional and Metabolic Diversity Phylogeny of Prokaryotes Ecological Impact.
The Basics of Bacteria. What are bacteria? Bacteria are single-celled prokaryotes Bacteria are single-celled prokaryotes DNA is not located in a nucleus.
Prokaryotes: Bacteria. Bacteria Found on almost every square cm of Earth Bacteria = prokaryotes –Remember: no nucleus and no membrane bound organelles.
AP Biology Archaebacteria & Bacteria Classification Old 5 Kingdom system Monera, Protists, Plants, Fungi, Animals New 3 Domain system reflects.
Prokaryotic diversity Eubacteria & Archaebacteria Campbell & Reese Fig 26.1.
+ Bacteria and Archaea. + Cell surface markers of prokaryotes Most bacteria contain peptidoglycan in their cell walls, which is a polymer of modified.
Chapter 27 - Prokaryotes. Structural features: Chapter 27 - Prokaryotes Structural features: Nearly all have a cell wall.
18.1 Bacteria Objectives: 8(C) Compare characteristics of taxonomic groups, including archaea, bacteria, protists, fungi, plants, and animals. 11(C) Summarize.
Bacteria Characteristics of Bacteria | Reproduction of Bacteria.
Regents Biology Ch Viruses Overview: A Borrowed Life Viruses called bacteriophages can infect and set in motion a genetic takeover of bacteria,
Topic 9 The Ecology of Prokaryotes Biology 1001 October 19, 2005.
CHAPTER 27 BACTERIA and ARCHAEA 1. OVERVIEW 1. Earliest organisms on Earth 2. Dominate biosphere 3. Live everywhere 4. Commonly referred to as “bacteria”
The Prokaryotes Chapter 16. Virus Bacterium Animal cell Animal cell nucleus 0.25 µm.
Prokaryotes Think!!!!: What is the study of microorganisms called? What is the study of bacteria called? Think!!!!: What is the study of microorganisms.
Chapter 23. Cellular organisms In one of two domains: Archaea and Eubacteria Generally smaller than eukaryotes Most are unicellular, some form.
Prokaryotes Prokaryotes are microscopic single-celled organisms. Although you cannot see them without the aid of a microscope, their combined biomass is.
The world of prokaryotes A- They’re everywhere 1- Collective prokaryote biomass outweighs all eukaryotes combined by at least tenfold. 2. They exist almost.
Objective: Chapter 27- Domain Bacteria and Archaea (The Prokaryotes) Do Now:
PAP Bacteria and Virus Notes Ch 19. Bacteria are grouped into two kingdoms: -Eubacteria and Arcahebacteria -Eubacteria and Archaebacteria have different.
PROKARYOTE Bacteria. Two Types Eubacteria Live in many places Cell wall protects and gives shape Peptidoglycan Archaebateria No peptidoglycan.
CHAPTER 19 NOTES BACTERIA CHARACTERISTICS OF BACTERIA Prokaryotic or Eukaryotic: Prokaryotic Unicellular or Multicellular: Unicellular Autotroph or Heterotroph:
Ch. 27 Bacteria and Archaea Objective: Understand the general structure and motility of bacteria and how genetic recombination increases diversity.
Prokaryotes By Aram Gebretensae and Quddus Akinlusi.
© 2017 SlidePlayer.com Inc. All rights reserved.