02/17/09
http://en.wikipedia.org/wiki/Eukaryote
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I.
General Characteristics of Eukaryotic Cells
II.
Cell Structures
A. Plasma Membrane
1. Comparing the Eukaryotic and Prokaryotic Cell Membrane
2. Cytosis
B. Eukaryotic Cell Walls
C. Eukaryotic Structures External to the Cell Wall
1. Glycocalyx
2. Movement Appendages
3. Attachment Appendages
4. Cell Surface Molecules
D. Structures Internal to the Plasma Membrane: Cytoplasm
1. Eukaryotic Nucleus
2. Structures Common to both Prokaryotic and Eukaryotic Cells
Review.
a. Ribosomes
b. Inclusions
3. Eukaryotes only!
Complexity, Compartmentalization, INTERNAL MEMBRANES
a. Cytoskeleton
b. Chloroplasts
c. Mitochondria
d. ER and Golgi Complex
e. Lysosomes and Peroxisomes
f. Vesicles and Vacuoles
III. Progression from Prokaryotic Cells to Eukaryotic
Cells
Yeast (Candida albicans)
http://www.cat.cc.md.us/courses/bio141/lecguide/u
nit1/proeu/u1fig2.html
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I. General Characteristics of Eukaryotic Cells
A. Eukaryotic cells are generally larger and much more complex than prokaryotic
cells.
Comparing sizes: Animation comparing viruses, bacteria, eukaryotic cells
http://www.cellsalive.com/howbig.htm
B. Many different shapes and sizes.
C. Eukaryotic microbes:
II. Cell Structures
centriole
s
nucleus
vacuole
Endoplasmic
reticulum
Ribosomes
(on ER)
mitochondrion
plasma
membrane
cytoplasm
cytoskeleton
peroxisomes
Golgi complex
lysosome
s
vesicle
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A. Plasma Membrane
1. Comparing the Eukaryotic and Prokaryotic Cell Membrane
2. Functions of the Plasma Membrane
a. Semipermeability: Cytosis
Eukaryotic cells undergo transport systems that prokaryotes do not: Cytosis -A
transport process in which
1) a substance is engulfed by the cytoplasmic membrane to form a vesicle
inside the cell containing the substance or
2) when a vesicle already in the cell fuses with the plasma membrane
releasing the contents of the vesicle out of the cell.

Endocytosis- movement into the cell

Exocytosis- movement out of the cell
3. Other functions of the plasma membrane:
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B. Eukaryotic Cell Walls
a. Plants, fungi, and some protists contain a cell wall, but the chemical
composition is different from Bacteria and Archaea.
b. There is never peptidoglycan.
c. Animals and protozoa do not have cell walls.
C. Eukaryotic Structures External to the Cell Wall
1. Glycocalyx: Eukaryotic cells also may have a sticky glycocalyx which
functions for: cell-to-cell attachment, cell recognition, or strengthening of cell
surface.
2. Movement Appendages: flagella, cilia
4. Attachment Appendages
4. Cell Surface Molecules
E. Structures Internal to the Plasma Membrane in the cytoplasm
1. Eukaryotic Nucleus- Several linear chromosomes contain the DNA
2. Structures Common to both Prokaryotic and Eukaryotic Cells
Review.
a. Ribosomes
1) Bacterial and Archael ribosomes are similar in size to each other (both
smaller than eukaryotic ribosomes) but have different rRNA and protein
components.
2) All three cell types have different rRNA molecules and proteins.
However the archaeal and eukaryal rRNA components are more similar to
each other than to bacteria.
3) Because the three cell types have differences in their ribosome size and
molecular structure, different chemicals will interfere in protein synthesis.
b. Inclusions-Most eukaryotes also have inclusions which function as reserves of
materials.
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3. Eukaryotes only: Complexity, Compartmentalization, MEMBRANES
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 carry out metabolism,
provide energy, and transport chemicals throughout the cell (most of the things needed for
a particular function are kept together).
a. Cytoskeleton: Functions to maintain structure, move cellular components
around the cell, and cell movement.
-Composed of protein rods and tubules in a complex network throughout the cell
b. Chloroplasts: Found in photosynthetic eukaryotes (plants and algae)
c. Mitochondria
1. Function in cellular respiration: Glucose is broken down and the energy
is stored in ATP.
2. ‘Powerhouse’ of the cell
d. Endoplasmic reticulum (ER) and Golgi complex
1. Organelles composed of folded and elongated stacked membranes,
respectively.
2. Involved in...
a) Molecule modification
b) Membrane synthesis
c) Molecule storage
d) Molecule transport
e. Lysosomes & Peroxisomes: Contain digestive and detoxifying enzymes,
respectively
f. Vacuoles and Vesicles: Storage, transport, excretion of waste
g. Centrioles
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Fill in the summary table from your notes:
How long have they been
here?
Bacteria
~3.5+ billion years ago.
Archaea
~3.5+ billion years ago.
Eukarya
~1.2-1.4 billion years ago.
Basic cell structure:
Prokaryotic or Eukaryotic
(Basic differences?)
Plasma membrane
structure
Cell wall structure
Structure external to the
cell wall
Chromosome structure
Ribosomes
Internal
structures/organelles
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III. Progression from Prokaryotic Cells to Eukaryotic Cells
Endosymbiotic Theory:
-Mitochondria and Chloroplasts
A. Prokaryotic-like cell engulfed smaller prokaryotic-like cell in a manner similar to
endocytosis; the engulfed cell was not destroyed and remained in a symbiotic relationship
with the larger cell.
B. Supporting evidence:
1. Mitochondria & chloroplast ribosomes are the same size as bacteria and archae;
rRNA sequence shows similarity to some archaea & bacteria.
2.
3.
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Exam Review
1. Know the general characteristics concerning Eukaryotic cells. Know one hypothesis for
the compartmentalization of eukaryotic functions into various organelles.
2. What differences are there between eukaryal and prokaryotic transport across the plasma
membrane (i.e., group translocation and cytosis)?
3. Briefly describe Eukaryotic cell walls and their chemical composition.
4. Be able to define/describe the terms cytoplasm, organelle, membrane-bound.
5. Compare Prokaryotic and Eukaryotic DNA (definitions/descriptions): nucleus, nucleoid,
plasmids.
6. Be able to define/describe and list the functions of ribosomes and inclusions. Compare
Bacterial, Archael, and Eukaryotic ribosome structure.
7. Be able to describe structures only found in eukaryotic cells.
8. Describe the Endosymbiotic theory: Organelles involved, theory description, supporting
evidence.
9. What structures do all cell types have in common? Although these structures are found
in all types of cells, how are they different -in the details?
10. Be able to answer the following type of question:
Which one of the following cellular molecules or structures is primarily involved in the
following life process: Response to the environment (example)
a. Endoplasmic reticulum
b. Cell surface molecules
c. Ribosomes
d. Inclusions
11. Be able to answer the following type of question:
According to available information, state whether the descriptions in questions 10-16 best depict:
a) Bacterial cells only, b) Archaeal cells only, c) Eukaryotic cells only, d) All three types of cells
or e) archaeal and eukaryotic cells only.
(Example)
1. Phospholipids in the plasma membreane may contain branched isoprene chains and an
ether linkage between the isoprenes and L-glycerol
2. Undergo passive diffusion across the plasma membrane
12. Know the definitions of all terms in the handouts.
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