Bacterial Cellular Anatomy and Its Effects on Disease, Immunity, Treatment
Tortora, Funke and Case
Outline
Note: The following abbreviations are used to indicate objectives and questions
you need to know for the exams
LO = Learning Objectives found at the beginning of text sections
CYU = Check Your Understanding questions found at the end of text sections
Q = Questions found under figures
Study Questions at the end of each chapter: (R = Review, MC = Multiple Choice,
CT = Critical Thinking, CA = Clinical Applications)
Chap. 4 Functional Anatomy of Prokaryotic and Eukaryotic Cells
LO/CYU: 4-1
I. Comparing Prokaryotic and Eukaryotic Cells: An Overview
p. 76-77, Also see Table 4.2 p. 101
Fig. 4.6 p. 80 Foundation Figure The Structure of a Prokaryotic Cell
Slide 1
Fig. 4.22 p. 99 The Eukaryotic Cell
Slide 2
Table 4.2 p. 101 See picture of Eukaryotic/Prokaryotic size difference in Table 4.2
p. 101 Slide 3
FYI:
Comparing Sizes: Animation comparing viruses, bacteria, eukaryotic cells
http://www.cellsalive.com/howbig.htm
Eukaryotic cells are highly compartmentalized. A large surface-to-volume ratio, as seen in
smaller prokaryotic cells, means that nutrients can easily and rapidly reach any part of the
cells interior. However, in the larger eukaryotic cell, the limited surface area when
compared to its volume means nutrients cannot rapidly diffuse to all interior parts of the
cell. That is why eukaryotic cells require a variety of specialized internal organelles to
transport chemicals throughout the cell and carry out life functions (most of the things
needed for a particular function are kept together in membranous structures rather than
free-floating).
1
The Prokaryotic Cell
Intro:
 As you go through the chapter, note ways that Archaea differ from
Bacteria
 How are bacteria differentiated from one another?
 As you go through the chapter, note ways that Prokaryotes differ from
Eukaryotes
II. The Size, Shape, and Arrangement of Bacterial Cells
LO/CYU: 4-2
A. Size: ~0.2m in diameter and 2-8m in length
B. Shapes and Arrangements: Be able to recognize the basic shapes and
arrangements
1. Be able to recognize the basic shapes (plus be aware that there are
others-star, square, etc.)
Fig. 4.1, 4.2, & 4.4 p. 78, 79, Fig. 4.5 p. 79
a. Coccus
b. Bacillus
c. Spiral (vibrio, spirilla, spirochetes)
-monomorphic v. pleomorphic
2. Be able to recognize the arrangements: single, diplo, strepto,
tetrads, sarcinae, staphylococcus, coccobacilli
Fig. 4.1 p. 78, Fig. 4.2 p. 79
III. Structures External to the Cell Wall
p. 79-84
See Fig. 4.6 p. 80 Foundation Figure The Structure of a Prokaryotic Cell (Slide 1)
A.
Glycocalyx
2
LO/CYU: 4-3
What is the importance of the glycocalyx?
See Slides 4-7
Fig. 8.24 p. 235
3
4
Chap. 16 Innate Immunity: pp.449 & 450, 454-460, Fig. 16.1, Table 16.1
I. Introduction p. 449
A. Immunity, Resistance, Susceptibility
B. Two lines of defense
1. First line of defense: skin and mucous membranes
2. What does the second line of defense consist of?
3. What is our third line of defense? (See Fig. 16.1 p. 450)
II. The Concept of Immunity pp. 450
A. Innate vs. Adaptive Immunity: What are the differences?
B. Innate Immunity: Describe macrophages, dendritic cells, Toll-like
receptors, PAMPs, and cytokines
III. First Line of Defense: Skin and Mucous Membranes
A.Physical Factors and Chemical Factors
One example- Lysozyme: Read this and watch the uTube video:
http://www.npr.org/blogs/health/2012/01/19/145466010/how-tears-gopac-man-to-beat-bacteria
B. Normal Microbiota and Innate Immunity p. 453
How does our normal microbiota help to protect us against pathogens?
What could happen concerning the normal microbiota if the
environmental conditions (in our bodies) change?
IV. Second Line of Defense (pp. 454-460)
What is included in the second line of defense?
A. Formed Elements in the Blood Table 16.1 p. 455
1. In general, what does blood consist of?
5
2. Leukocytes
a. Granulocytes: Know their function
1) Neutrophils
2)Basophils
3) Eosinophils
b. Agranulocytes: Know their function
1)Monocytes and Macrophages
2) Dendritic cells
3)Lymphocytes
a)Natural Killer cells
b) T cells
c) B cells
B. The Lymphatic System
1. What does the lymphatic system consist of? (See Fig. 16.5 for
clarification)
2. Describe the functions/ activities of the lymphatic system.
3. Where is lymphatic tissues and organs located?
4. Describe some large aggregations of lymphoid tissues.
C. Phagocytes
1. Actions of Phagocytic cells
a. Describe what happens when an infection occurs?
b. What phagocytic cells are involved?
c. How does the type of white blood cell shift during the
course of an infection?
6
2. Mechanism of Phagocytosis: Describe the steps of phagocytosis
LO/CYU 16-7, 16-8, 16-9, 16-10
Fig. 16.7 p. 458 Foundation Figure The Mechanism of Phagocytosis
a. Chemotaxis
b. Adherence
c. Ingestion
d. Phagosome formation
e. Phagosome and Lysosome fusion: Phagolysosome
d. Digestion
e. Residual body formation
f. Discharge
3. Microbial Evasion of Phagocytosis:
Describe several ways microbes evade destruction by a
phagocyte, especially HIV and biofilms.
Go back to Chap. 4
7
B. Flagella Fig. 4.7 p. 81
LO/CYU: 4-4
1. Taxis- movement toward/away from a stimulus
2. Several proteins, including flagellin
3. H antigen (a protein in flagella)- distinguishes between variations
within a species (serovars)
E. coli 0157:H7 (food-borne epidemics)
C. Axial Filaments: Spirochetes only (Ex.: Trepnema)
Fig. 14.11 a p. 84
8
D. Fimbriae and Pili (shorter, straighter, thinner than flagella) p.83
1. Contain protein pilin
2. Fimbriae Slide 8 Fig. 14.10 b p. 84
a. Attachment
b. A few to several hundred per cell.
c. Ex.: Neisseria gonorrhoeae (see Fig. 11.6 p. 306)
and E. coli 0157:H7 (see text p. 717-718)
2. Pili
Slide 9
a. Usually longer than fimbriae and only 1 or 2 per cell.
b. Motility: Twitching and Gliding
c. Conjugation pili
(Transfer of DNA from one bacterial cell to another)
Fig. 8.26 p. 237 Bacterial conjugation.
9
Note: See Fig. 20.2 p. 556 for Major
modes of Action of Antimicrobial
Drugs
IV. The Cell Wall
LO/CYU: 4-5
Major function of the cell wall?
A. Composition and Characteristics
Refer to Figure 4.6 p. 80 The Structure of the Prokaryotic Cell Wall -Slide 1
Peptidoglycan (murein)
Only in bacterial cell
walls.
-Disaccharide (NAG-NAM)
-The rows of NAG-NAMs are connected by side chains made of 4
amino acids
-Short peptide cross-bridges may also be present that link the side
chains
Also found in Slide 10 Fig. 4.13 a Bacterial Cell Walls p. 86
10
1. Gram-Positive Cell Walls
a. Many layers of peptidoglycan
b. Teichoic acids (alcohol and phosphate) present
c. Other molecules may be present (Different Strep “groups”
have specific polysaccharides)
Figure is also found in Slide 11 Fig. 4.13 b Bacterial Cell Walls p. 86
Slide 12
Fig. 21.4 Lesions of Impetigo p. 588 – caused by Staph aureus
Fig. 21.8 Necrotizing fasciitis due to group A streptococci
11
2. Gram-Negative Cell Walls
Also found in Slide 13 Fig. 4.13 c p. 86 Gram-negative cell wall details
a. Periplasm
1) Contains one or only a few peptidoglycan layers
2) Lipoproteins connect the peptidoglycan to the outer
membrane (see below)
3) Other molecules: Ex: degradative enzymes and
transport proteins
b. Outer Membrane (OM)
OM is semi-permeable: only allows
some things in and out of the cell,
some things are restricted.
IMPORTANT!!! Certain drugs and
chemicals won’t penetrate the OM
and can’t be used- ex: penicillin is
less effective against G- cells.
BAD!! Common cause of most
severe form of sepsis, called septic
shock: fever, blood vessel dilation,
blood clotting (organ damage,
death) Slide 14
1) Phospholipid bilayer
2) Porin proteins with a channel for transporting nutrients
into the cell
3) Lipopolysaccharide (LPS, endotoxin)
Slide
a) Released from the OM when the cell lyses.
b) 3 parts to an LPS molecule:
12
(1) Lipid A anchors the LPS in the top
phospholipid layer of OM
Examples G-: E. coli O157:H7, Yersinia
pestis (plague)
(2) Core polysaccharide stabilizes the LPS
(3) O polysaccharide extends out from the
core polysaccharide
Different species have distinctive O
polysaccharides which can be used for
identification.
E. coli 0157: H7
B. Cell Walls and Gram Staining
Slide 15
C. Atypical Cell Walls
1.
Archaea: May have no cell walls, and if they do, they never
contain peptidoglycan. If they do have cell walls, may contain
pseudomurein , which has N-acetyltalosaminuronic instead of
NAM
2. Bacteria with no cell walls: Mycoplasmas, Spiroplasma,
Ureaplasma
LO/CYU: 4-6
Mycoplasmas are the smallest free-living cellular organisms known
(0.1-2.5 micrometers). Since no cell wall, often are pleomorphic.
Also contain sterols in their plasma membrane (protection from lysis).
Mycoplasm pneumoniae causes a mild form of pneumonia.
(What type of other microorganism does this bacterial name refer to?)
13
3. Acid-Fast Cell Walls: Mycobacterium
See Fig. 24.8 Mycobacterium tuberculosis p. 682
a. Mycolic acids take the place of the OM; connect to a thin
peptidoglycan layer with polysaccharides
b. Mycolic acids are lipids, waxy and water resistant.
c. Mycolic acids are why these cells are:

Difficult to stain (can stain by heating with the red acidfast stain, carbolfuchsin, that bonds to waxy materials)
 Resistant to many drugs, disinfectants and antiseptics,
and stresses (such as low water content-don’t dry out
easily)
 Slow growing (nutrients enter slowly) and cause certain
diseases (mycolic acids stimulate the inflammatory
response -many white blood cell macrophages come to
destroy the bacteria and release cytokines and enzymes
that actually damage lung tissues).
 Important diseases: M. tuberculosis, M. leprae, Nocardia
D. Damage to Cell Wall p. 88, 89
1. Why don’t chemicals that damage bacterial cell walls or prevent
their synthesis cause damage to the cell walls of humans?
2. Penicillin
3. Lysozyme
Why do chemicals that affect the cell wall
of bacteria, especially the peptidoglycan,
most often work best with Gram-positive
bacteria?
14
V. Structures Internal to the Cell Wall
A. Plasma Membrane (or inner membrane if you are Gram-)
1. Structure
LO/CYU: 4-8
Fluid Mosaic Model
a. Phospholipid bilayer
Hydrophobic and Hydrophilic components
b. Proteins
c. Carbohydrates attached to a lipid (glycolipids) &
Carbohydrates attached to protein (glycoprotein)- Roles in
protection, cell interactions, bonding sites for pathogens
(influenza viruses, cholera and botulism toxins)
Also found in Slide 16 Fig. 4.14 p. 90
15
2. Functions of the Plasma Membrane
a. Selective permeability
b. Nutrient break-down (enzymes)
c. ATP production (efficient energy)
d. Photosynthesis- enzymes and pigments
3. Destruction of the Plasma Membrane
a. Certain disinfectants (example alcohols)
Note: See Fig. 20.2
p. 556 for Major
modes of Action of
Antimicrobial Drugs
b. Certain antibiotics: polymyxins
B. Movement of Materials across Membranes
LO/CYU: 4-9
1. Passive Processes – No energy used
a. Simple and Facilitated Diffusion
Fig. 4.17 a and b p. 92
16
b. Osmosis Fig. 4.17d p. 92 and Fig. 4.18 p. 93
See Slide 17 Fig. 4.18 for osmosis under various environmental conditionsWhat happens to the cell under each of these conditions?
2. Active Processes – Use energy because the transported substance
moves against the concentration gradient.
Use transporter proteins, enzymes, other processes
a. Active Transport: Requires a transporter protein
b. Group Translocation: Requires a transporter protein
Substance is chemically altered as it is being transported into
the cell. -Only occurs in Prokaryotes
c. Endocytosis & Exocytosis : Only occur in Eukaryoytes
17
B. Cytoplasm
C. Nucleoid
LO/CYU: 4-10
Bacterial chromosome vs. Plasmids
Fig. 4.6 p. 80
D. Ribosomes
E. Inclusions
LO/CYU: 4-11
F. Endospores- Sporulation/Germination
LO/CYU: 4-12
Fig. 4.21 p. 97
Slide 18
18
The Eukaryotic Cell
Fig. 4.22 p. 99 Eukaryotic cells showing typical structures.
Slide 2
Principle Differences between Prokaryotic and Eukaryotic Cells Table 4.2 p. 101
CYU: 4-4-13-4-16
I. Flagella and Cilia
II. The Cell Wall and Glycocalyx
III. Plasma (Cytoplasmic) Membrane
LO/CYU: 4-16
IV. Cytoplasm
V. Ribosomes
LO/CYU: 4-17
VI. Organelles (Membrane-bound)
List: Slides 20 & 21
A. Nucleus Fig. 4.24 a, b p. 102
Slide 19
CYU: 4-18
B. Endoplasmic Reticulum: rough and smooth
C. Vesicles & Golgi Complex
D. Lysosomes
E. Mitochondria
F. Chloroplasts
G. Peroxisomes
H. Centrosome
19
VII. Evolution of Eukaryotes
A. Endosymbiotic Theory
LO: 4-20
Slide 22
Fig. 10.2 p. 277 A model of the origin or eukaryotes
Table 10.2 p. 276 Prokaryotic Cells and Eukaryotic Organelles Compared
Slide 23
Table 10.1 p. 276 Comparing some Characteristics of Archaea, Bacteria, and
Eukarya Slide 24
Additional study Questions:
End of Chapter Study Question:
Review: 2, 4, 5, 6, 7c&e, 9
Multiple Choice: 1, 2, 3, 9
Critical Thinking: 3, 4
Clinical Applications: 1
20