BIO 225 (Microbiology) CHAPTER
OUTLINE FOR BACTERIA AND
ARCHAE FROM MICROBIOLOGY
FUNDAMENTALS A CLINICAL
APPROACH, COWAN SMITH GREENE
VILLE TECHNICAL COLLEGE
, Chapter 3: Bacteria and Archaea
Bacteria and Archaea: An Overview
How bacteria and archaea are different from eukaryotes:
• The way their DNA is packaged: have no nucleus so DNA is “free
floating”
• The makeup of their cell wall: have a strong cell wall of unique
molecules-
• Their internal structures: no “membrane-bound” organelle, so cellular
process are in cytoplasm
Bacterial Shapes and Arrangements
Most bacteria function as independent unicellular organisms.
• Some act as a group in colonies or biofilms.
• May communicate through chemicals and/or nanotubes
Bacteria have an average size of 1 μm (micron).
Some bacterial species are pleomorphic (change in bacteria’s characteristic
depending on environmental factors: pH pr temperature) but most can be
described by a species-specific shape and arrangement
3 basic shape of bacteria (Figure 3.3)
• Coccus (Fig 3.5), (most diverse because they can divide into more
than one plane)(spherical or ball-shaped)
• Bacillus, (less varied because they can only divide in one plane)
(cylindrical, rod-shaped)
• Curved or spiral (spiral cell; looks like corkscrew)
Bacterial Cell Structure (Fig 3.1)
Appendages for Motility
Flagella
• Function: (motility by transforming biochemical energy from bacteria
into mechanical energy for movement), accomplished through flagellar
rotation
• Flagellar Arrangements (Fig 3.8)
o Monoicous: (bacteria with one flagella)
OUTLINE FOR BACTERIA AND
ARCHAE FROM MICROBIOLOGY
FUNDAMENTALS A CLINICAL
APPROACH, COWAN SMITH GREENE
VILLE TECHNICAL COLLEGE
, Chapter 3: Bacteria and Archaea
Bacteria and Archaea: An Overview
How bacteria and archaea are different from eukaryotes:
• The way their DNA is packaged: have no nucleus so DNA is “free
floating”
• The makeup of their cell wall: have a strong cell wall of unique
molecules-
• Their internal structures: no “membrane-bound” organelle, so cellular
process are in cytoplasm
Bacterial Shapes and Arrangements
Most bacteria function as independent unicellular organisms.
• Some act as a group in colonies or biofilms.
• May communicate through chemicals and/or nanotubes
Bacteria have an average size of 1 μm (micron).
Some bacterial species are pleomorphic (change in bacteria’s characteristic
depending on environmental factors: pH pr temperature) but most can be
described by a species-specific shape and arrangement
3 basic shape of bacteria (Figure 3.3)
• Coccus (Fig 3.5), (most diverse because they can divide into more
than one plane)(spherical or ball-shaped)
• Bacillus, (less varied because they can only divide in one plane)
(cylindrical, rod-shaped)
• Curved or spiral (spiral cell; looks like corkscrew)
Bacterial Cell Structure (Fig 3.1)
Appendages for Motility
Flagella
• Function: (motility by transforming biochemical energy from bacteria
into mechanical energy for movement), accomplished through flagellar
rotation
• Flagellar Arrangements (Fig 3.8)
o Monoicous: (bacteria with one flagella)
