Bacterial Cell Structure, Physiology,
Metabolism, and Genetics
Connie R. Mahon *, George Manuselis
CHAPTER OUTLINE
■ SIGNIFICANCE
■ OVERVIEW OF THE MICROBIAL WORLD
Bacteria
Parasites
Fungi
Viruses
■ CLASSIFICATION/TAXONOMY
Nomenclature
Classification by Phenotypic and Genotypic Characteristics
Classification by Cellular Type: Prokaryotes, Eukaryotes, and
Archaea
■ COMPARISON OF PROKARYOTIC AND EUKARYOTIC CELL
STRUCTURE
Prokaryotic Cell Structure
Eukaryotic Cell Structure
Cytoplasmic Structures
■ BACTERIAL MORPHOLOGY
Microscopic Shapes
Common Stains Used for Microscopic Visualization
■ MICROBIAL GROWTH AND NUTRITION
Nutritional Requirements for Growth
Environmental Factors Influencing Growth
Bacterial Growth
■ BACTERIAL BIOCHEMISTRY AND METABOLISM
Metabolism
Fermentation and Respiration
Biochemical Pathways from Glucose to Pyruvic Acid
41
, Anaerobic Utilization of Pyruvic Acid (Fermentation)
Aerobic Utilization of Pyruvate (Oxidation)
Carbohydrate Utilization and Lactose Fermentation
■ BACTERIAL GENETICS
Anatomy of a DNA and RNA Molecule
Terminology
Genetic Elements and Alterations
Mechanisms of Gene Transfer
OBJECTIVES
After reading and studying this chapter, you should be able to:
1. Describe microbial classification (taxonomy), and accurately apply the rules of scientific
nomenclature for bacterial names.
2. List and define five methods used by epidemiologists to subdivide bacterial species.
3. Differentiate among archaeal, prokaryotic (bacterial), and eukaryotic cell types.
4. Compare and contrast prokaryotic and eukaryotic cytoplasmic and cell wall structures
and functions.
5. Compare and contrast the cell walls of gram-positive and gram-negative bacteria.
6. Compare the acid-fast cell wall with other gram-positive cell walls.
7. Apply the use of the following stains in the diagnostic microbiology laboratory: Gram
stain, acid-fast stains (Ziehl-Neelsen, Kinyoun, auramine-rhodamine), acridine orange,
methylene blue, calcofluor white, lactophenol cotton blue, and India ink.
8. List the nutritional and environmental requirements for bacterial growth and define the
categories of media used for culturing bacteria in the laboratory.
9. Define the atmospheric requirements of obligate aerobes, microaerophiles, facultative
anaerobes, obligate anaerobes, and capnophilic bacteria.
10. Define aerotolerant anaerobe.
11. Describe the stages in the growth of bacterial cells.
12. Explain the importance of understanding microbial metabolism in clinical microbiology.
13. Differentiate between fermentation and oxidation (respiration).
14. Name and compare three biochemical pathways that bacteria use to convert glucose
to pyruvate.
15. Compare the two types of fermentation that explain positive results with the methyl red
or Voges-Proskauer tests.
16. Define the following genetic terms: genotype, phenotype, constitutive, inducible,
replication, transcription, translation, genome, chromosome, plasmids, insertion
42
, sequence element, transposon, point mutations, frameshift mutations, and
recombination.
17. Discuss the development and transfer of antimicrobial resistance in bacteria.
18. Differentiate among the mechanisms of transformation, transduction, and conjugation
in the transfer of genetic material from one bacterium to another.
19. Define the terms bacteriophage, lytic phage, lysogeny, and temperate phage.
20. Define the term restriction endonuclease enzyme, and explain the use of such
enzymes in the clinical microbiology laboratory.
KEY TERMS
Acid-fast
Aerotolerant anaerobes
Anticodon
Archaea
Autotrophs
Bacteria
Bacteriophage
Capnophilic
Capsule
Codon
Competent
Conjugation
Differential media
Dimorphic
Eukarya
Eukaryotes
Facultative anaerobes
Family
Fermentation
Fimbriae
Flagella
Fusiform
Genotype
Genus
43
, Gram-negative
Gram-positive
Halophiles
Heterotrophs
Hyphae
Krebs cycle
Lysogeny
Mesophiles
Microaerophilic
Minimal medium
Mycelia
Nomenclature
Nutrient media
Obligate aerobes
Obligate anaerobes
Pathogenic bacteria
Phenotype
Phyla
Pili
Plasmids
Pleomorphic
Prokaryotes
Protein expression
Psychrophiles
Respiration (oxidation)
Restriction enzymes
Selective media
Species
Spores
Strains
Taxa
Taxonomy
Temperate
Thermophiles
Transcription
44
Metabolism, and Genetics
Connie R. Mahon *, George Manuselis
CHAPTER OUTLINE
■ SIGNIFICANCE
■ OVERVIEW OF THE MICROBIAL WORLD
Bacteria
Parasites
Fungi
Viruses
■ CLASSIFICATION/TAXONOMY
Nomenclature
Classification by Phenotypic and Genotypic Characteristics
Classification by Cellular Type: Prokaryotes, Eukaryotes, and
Archaea
■ COMPARISON OF PROKARYOTIC AND EUKARYOTIC CELL
STRUCTURE
Prokaryotic Cell Structure
Eukaryotic Cell Structure
Cytoplasmic Structures
■ BACTERIAL MORPHOLOGY
Microscopic Shapes
Common Stains Used for Microscopic Visualization
■ MICROBIAL GROWTH AND NUTRITION
Nutritional Requirements for Growth
Environmental Factors Influencing Growth
Bacterial Growth
■ BACTERIAL BIOCHEMISTRY AND METABOLISM
Metabolism
Fermentation and Respiration
Biochemical Pathways from Glucose to Pyruvic Acid
41
, Anaerobic Utilization of Pyruvic Acid (Fermentation)
Aerobic Utilization of Pyruvate (Oxidation)
Carbohydrate Utilization and Lactose Fermentation
■ BACTERIAL GENETICS
Anatomy of a DNA and RNA Molecule
Terminology
Genetic Elements and Alterations
Mechanisms of Gene Transfer
OBJECTIVES
After reading and studying this chapter, you should be able to:
1. Describe microbial classification (taxonomy), and accurately apply the rules of scientific
nomenclature for bacterial names.
2. List and define five methods used by epidemiologists to subdivide bacterial species.
3. Differentiate among archaeal, prokaryotic (bacterial), and eukaryotic cell types.
4. Compare and contrast prokaryotic and eukaryotic cytoplasmic and cell wall structures
and functions.
5. Compare and contrast the cell walls of gram-positive and gram-negative bacteria.
6. Compare the acid-fast cell wall with other gram-positive cell walls.
7. Apply the use of the following stains in the diagnostic microbiology laboratory: Gram
stain, acid-fast stains (Ziehl-Neelsen, Kinyoun, auramine-rhodamine), acridine orange,
methylene blue, calcofluor white, lactophenol cotton blue, and India ink.
8. List the nutritional and environmental requirements for bacterial growth and define the
categories of media used for culturing bacteria in the laboratory.
9. Define the atmospheric requirements of obligate aerobes, microaerophiles, facultative
anaerobes, obligate anaerobes, and capnophilic bacteria.
10. Define aerotolerant anaerobe.
11. Describe the stages in the growth of bacterial cells.
12. Explain the importance of understanding microbial metabolism in clinical microbiology.
13. Differentiate between fermentation and oxidation (respiration).
14. Name and compare three biochemical pathways that bacteria use to convert glucose
to pyruvate.
15. Compare the two types of fermentation that explain positive results with the methyl red
or Voges-Proskauer tests.
16. Define the following genetic terms: genotype, phenotype, constitutive, inducible,
replication, transcription, translation, genome, chromosome, plasmids, insertion
42
, sequence element, transposon, point mutations, frameshift mutations, and
recombination.
17. Discuss the development and transfer of antimicrobial resistance in bacteria.
18. Differentiate among the mechanisms of transformation, transduction, and conjugation
in the transfer of genetic material from one bacterium to another.
19. Define the terms bacteriophage, lytic phage, lysogeny, and temperate phage.
20. Define the term restriction endonuclease enzyme, and explain the use of such
enzymes in the clinical microbiology laboratory.
KEY TERMS
Acid-fast
Aerotolerant anaerobes
Anticodon
Archaea
Autotrophs
Bacteria
Bacteriophage
Capnophilic
Capsule
Codon
Competent
Conjugation
Differential media
Dimorphic
Eukarya
Eukaryotes
Facultative anaerobes
Family
Fermentation
Fimbriae
Flagella
Fusiform
Genotype
Genus
43
, Gram-negative
Gram-positive
Halophiles
Heterotrophs
Hyphae
Krebs cycle
Lysogeny
Mesophiles
Microaerophilic
Minimal medium
Mycelia
Nomenclature
Nutrient media
Obligate aerobes
Obligate anaerobes
Pathogenic bacteria
Phenotype
Phyla
Pili
Plasmids
Pleomorphic
Prokaryotes
Protein expression
Psychrophiles
Respiration (oxidation)
Restriction enzymes
Selective media
Species
Spores
Strains
Taxa
Taxonomy
Temperate
Thermophiles
Transcription
44
