Download Chapter 4 Prokaryotic vs Eukaryotic

CHAPTER 4
CHARACTERISTICS OF PROKARYOTIC AND EUKARYOTIC CELLS
 Chapter Overview
This chapter provides an in-depth look at the structure and function of prokaryotic and
eukaryotic cells.
A detailed study of prokaryotic structure is extremely valuable because it provides important
information on how antibiotics work, how microbes undergo metabolism, how antibiotic resistant
develops, and how differential stains such as the Gram stain work. Even though prokaryotes are
considerably simpler than eukaryotic cells, they still possess many complex structures, such as
peptidoglycan layers and endospores that are not found in any other living organism. However, when
prokaryotic and eukaryotic cells are compared, similarities can also be found. For example, the cell
membrane in prokaryotes is basically identical to the cell membrane in eukaryotic cells. A study of
similarities and differences can help the student understand important biochemical and evolutionary
changes.
The last part of the chapter provides a brief presentation of the important mechanisms that
move substances across cell membranes. An understanding of these mechanisms is essential to an
understanding of how the cell functions. Both passive and active processes are presented, with the
emphasis placed on those mechanisms that are most important to microbiologists. Since this chapter
may be considered the foundation for later chapters, sufficient time in lecture should be devoted to
ensure thorough coverage.
 Chapter Objectives
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Contrast the characteristics of eukaryotic and prokaryotic cell types.
Describe the sizes, shapes, and arrangements of prokaryotic cells, especially as they relate to
bacterial cells.
Describe the basic structure and function of the cell membrane and cell wall of bacterial cells.
List and describe the structure and function of internal cell components of bacteria, including
endospores.
Describe the structure and function of the external cell components of bacteria.
Describe the general structure of eukaryotic cells.
List and describe the structure and function of the internal components of eukaryotic cells.
Describe the structure and function of the external components of eukaryotic cells.
Explain the endosymbiotic theory and give examples of organelles that may have evolved by
endosymbiosis.
Describe the following passive processes, and explain their importance in cell function: simple
diffusion, facilitated diffusion, and osmosis
Describe the process of active transport, explaining how it differs from passive processes and why
it is important in cell function.
Describe the processes of exocytosis and endocytosis, and explain their importance in eukaryotic
cell function.
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 Web Destinations
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http://www.bact.wisc.edu/Microtextbook/TOC.html
On-line microbiology textbook
http://www.cellsalive.com/cells/3dcell.htm
Plant, animal, and bacterial cell models found at the Cells Alive website
Michael Gregory’s site on cells
http://faculty.clintoncc.suny.edu/faculty/Michael.Gregory/files/Bio%20101/bio_1_menu.htm
Michael Gregory’s General Biology 1 website, click on Mitosis Animation
http://personal.tmlp.com/Jimr57/textbook/chapter3/chapter3.htm
Virtual Cell Webpage
A. Wiley’s cell structure animations for plants, animals, and bacteria
http://www.wiley.com/legacy/college/boyer/0470003790/animations/cell_structur
e/cell_structure.htm
 Discussion Topics
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How could the process of endocytosis be used selectively to cause microbes to ingest antibiotics
or other poisonous substances?
Discuss the major unique bacterial components, peptidoglycan and 70S ribosomes. Explain how
antibiotics target these unique characteristics to control bacterial infections.
 Chapter Outline
I.
Basic Cell Types
A.
Prokaryotic cells
B.
Eukaryotic cells (have membrane-bound organelles)
II.
Prokaryotic Cells
A.
Size, shape, and arrangement
1.
Size
2.
Shapes
3.
Arrangements
B.
Overview of structure
C.
Cell wall
1.
Basic functions
2.
Components of cell walls
a.
Peptidoglycan
b.
Teichoic acids
c.
Outer membrane
d.
Lipopolysaccharide (endotoxin)
e.
Periplasmic space
3.
Distinguishing bacteria by cell walls
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D.
E.
F.
III.
a.
Gram-positive bacteria
b.
Gram-negative bacteria
c.
Acid-fast bacteria
d.
Controlling bacteria by damaging cell walls
4.
Wall-deficient organisms (L-forms)
Cell membrane
1.
Basic functions
2.
Fluid-mosaic model
a.
Hydrophilic
b.
Hydrophobic
Internal structure
1.
Cytoplasm
2.
Ribosomes
3.
Nuclear region
4.
Internal membrane systems
5.
Inclusions
a.
Granules
b.
Vesicles
6.
Endospores
a.
Sporulation
b.
Germination
External structure
1.
Flagella
a.
Types of flagella
b.
Composition
c.
Chemotaxis
d.
Phototaxis
2.
Axial filaments (endoflagella)
3.
Pili
a.
Conjugation pili
b.
Attachment pili
4.
Glycocalyx
a.
Capsule
b.
Slime layer
Eukaryotic Cells
A.
Overview of structure
B.
Plasma membrane
C.
Internal structure
1.
Cytoplasm
2.
Cell nucleus
a.
Basic features
b.
Chromosomes
c.
Mitosis
d.
Meiosis
3.
Mitochondria
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D.
E.
IV.
4.
Chloroplasts
5.
Ribosomes
6.
Endoplasmic reticulum
7.
Golgi apparatus
8.
Lysosomes
9.
Peroxisomes
10.
Vacuoles
11.
Cytoskeleton
External structure
1.
Flagella
2.
Cilia
3.
Pseudopodia
4.
Cell walls
Evolution by endosymbiosis
1.
Endosymbiotic theory
2.
Supporting evidence
Movement of Substances across Membranes
A.
Basic characteristics
B.
Simple diffusion
C.
Facilitated diffusion
D.
Osmosis
1.
Osmotic pressure
2.
Tonicity
E.
Active transport
F.
Endocytosis and exocytosis
1.
Endocytosis
2.
Exocytosis
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