Download Cells: Prokaryote vs Eukaryote

Cells: Prokaryote vs
Eukaryote
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Vocabulary
3/24 – explain how
3/24 – prokaryotic cells
prokaryotic cells move.
3/25 – flagella
3/25 – Name 2 kingdoms
3/26 – eukaryotic cells
that are prokaryotic.
3/27 - pili
3/26 – name the 4 kingdoms
that are eukaryotic cells.
3/27 – Compare the size of
eukaryotic and prokaryotic
cells
What to STUDY?????
•Know kingdoms for eukaryotic and prokaryotic cells.
•Know 4 similarities and differences – cell wall and
size!!!
•Know how prokaryotes reproduce
•Know pilli and nucleoid
•Know 4 ways they obtain food
•Know 3 bacteria that are harmful and what they
cause
•Know why bacteria make you sick
•Know 3 ways they are helpful
•Know examples of prokaryotes and eukaryotes
•Know the 3 shapes of bacteria
Two Basic Types of Cells
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From the Virtual Microbiology Classroom on ScienceProfOnline.com
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Images: Prokaryotic cell diagram &
Eukaryotic cell diagram, M. Ruiz
Cells have evolved two
different architectures:
Prokaryote “style” – before nucleus
Eukaryote “style” – true nucleus
Prokaryotic cells: No true nucleus
Eukaryotic cells: true nucleus
Prokaryotic Kingdoms
Archaebacteria - unicellular
Eubacteria - unicellular
Kingdoms
Plant – multi - cellular
Animal - multi - cellular
Fungi - multi - cellular
Protista - unicellular
SIMILARITIES:
1. They both have DNA as their genetic
material.
2. They are both membrane bound.
3. They both have ribosomes .
4. They have similar basic metabolism .
5. They are both amazingly diverse in forms.
6. cell wall, cell membrane
7. characteristics of life
8. cytoplasm
9. Both can be unicellular
DIFFERENCES:
1. Eukaryotes have a nucleus, while prokaryotes do not
2. Eukaryotes have membrane-bound organelles, while
prokaryotes do not.
3. Eukaryotic cells are, on average, ten times the size of
prokaryotic cells.
4. The DNA of eukaryotes is much more complex
5. Prokaryotes have a cell wall composed of peptidoglycan,
ALLOW ANTIBIOTICS TO KILL
6. The DNA of prokaryotes floats freely around the cell; the
DNA of eukaryotes is held within its nucleus
7. Eukaryotes undergo mitosis; prokaryotes divide by binary
fission (simple cell division)
Prokaryotic Cells
Eukaryotic cells
small cells (< 5 mm)
larger cells (> 10 mm)
always unicellular
often multicellular
no nucleus or any membrane-bound
organelles
always have nucleus and other
membrane-bound organelles
DNA is circular, FREE FLOATING
DNA
DNA is linear and associated with
proteins to form chromatin
ribosomes are small
ribosomes are large
Summary of differences!
no cytoskeleton PILLI and capsule
Cell wall made of peptidoglycan
always has a cytoskeleton
Cell wall made out of cellulose
cell division is by binary fission
cell division is by mitosis or meiosis
reproduction is always asexual
reproduction is asexual or sexual
Similarities between Prokaryotic and
Eukaryotic Cells
*Ribosomes
*DNA
*Cell membrane
*7 characteristics of life – reproduction, cells
*Some have cell walls
*Some have flagella
*Cytoplasm
Prokaryotic Cells
Prokaryotic cells lack a
membrane-bound nucleus.
-genetic material is present in
the nucleoid
16
Prokaryotic Cells
Prokaryotic cell walls
-protect the cell and maintain cell shape
-may be composed of peptidoglycan
Archaean cell walls lack peptidoglycan.
17
Prokaryotic Cells Have
-genetic material in the nucleoid
-cytoplasm
-cell membrane
-cell wall
-ribosomes
-no membrane-bound organelles
18
Prokaryotic Cells
Flagella
-present in some prokaryotic cells
-used for locomotion
-rotary motion propels the cell
19
Prokaryote cells are
smaller and simpler
Commonly known as bacteria
10-100 microns in size
Single-celled(unicellular)
These are
prokaryote
E. coli bacteria
on the head of
a steel pin.
Do ALL Cells have a cell membrane?
YES!!!
HOW IS A CELL MEMBRANE
DIFFERENT THAN A CELL
WALL?
7 Major Structures of a Bacteria Cell
•Capsule
•Cell wall
•Ribosomes
•Nucleoid
•Flagella
•Pilli
•Cytoplasm
7 Major Structures of a Bacteria Cell
Cell wall
Thick outer
covering that
maintains the
overall shape of
the bacterial
cell
7 Major Structures of a Bacteria Cell
Ribosomes
 cell part where
proteins are made
 Ribosomes give
the cytoplasm of
bacteria a granular
appearance in
electron
micrographs
7 Major Structures of a Bacteria Cell
Nucleoid
 a ring made
up of DNA
7 Major Structures of a Bacteria Cell
Flagella
 a whip-like
tail that some
bacteria have
for locomotion
7 Major Structures of a Bacteria Cell
Pilli
 hollow hairlike structures
made of protein
allows bacteria
to attach to
other cells.
Pilli-singular
Pillus-plural
7 Major Structures of a Bacteria Cell
Cytoplasm
 clear jellylike material
that makes up
most of the cell
Most prokaryotes are beneficial; we
couldn’t live without them. (e.g. Nitrogenfixing bacteria)
Some cause illness  bubonic plague,
diphtheria, salmonella
Approximately 5000 species have been
identified.
Archaea are thought to be more closely
related to eukaryotes than to bacteria.
Structure, function, and reproduction of
prokaryotes
II.
A. Most prokaryotes are unicellular.
B. Three (3) common shapes: cocci (round);
bacilli (rod); helical (spiral)
3 Shapes of Bacteria
Bacteria are classified by shape into 3
groups:
Spiral:
spirilla
rod-shaped:
bacilli, bacillus
Round:
Cocci
Staph strep
• Prokaryotic cells have a variety of shapes
– The three most common of which are spheres (cocci),
rods (bacilli), and spirals
1 m
(a) Spherical
Figure
27.2a–c(cocci)
2 m
(b) Rod-shaped (bacilli)
5 m
(c) Spiral
BINARY FISSION
Bacteria dividing
Completed
Reproduction of Bacteria
•Binary Fission- the process of one organism
dividing into two organisms
•Fission is a type of asexual reproduction
•Asexual reproduction- reproduction of a
living thing from only one parent
How?...
The one main (circular)
chromosome makes a
copy of itself
Then it divides into two
Prokaryote cells are simply built
(example: E. coli)
capsule: slimy outer
coating
cell wall: tougher middle
layer
cell membrane: delicate
inner skin
Prokaryote cells are simply built
(example: E. coli)
cytoplasm: inner liquid filling
DNA in one big loop
pilli: for sticking to things
flagella: for swimming
ribosomes: for building
proteins
Most prokaryotes secrete sticky substances that
form a protective layer and enable them to
adhere to substrates.
a. The sticky protective layer secreted by
prokaryotes is called the capsule.
b.Some prokaryotes adhere to substrates using
pili.
c. Some pili are specialized for DNA transfer. This
process is called conjugation; note for later in
class.
Prokaryote Feeding
Photosynthetic: energy from sunlight
Disease-causing: feed on living things
Decomposers: feed on dead things
Chemotrophs – Use the carbon and
other chemicals in environment to make
food.
What is a pathogen?
Microorganisms that make you sick
Why do they make you sick?
To get food they need to survive and reproduce
How do they make you sick?
They produce poisons (toxins) that result in
fever, headache, vomiting, and diarrhea and
destroy body tissue
USDA NIFSI Food Safety in the Classroom©
University of Tennessee, Knoxville 2006
Helpful Bacteria
•Used to treat sewage
Organic waste is consumed by the bacteria,
used as nutrients by the bacteria, and is no
longer present to produce odors, sludge,
pollution, or unsightly mess.
•foods like yogurt, cottage & Swiss cheese,
sour cream, buttermilk are made from
bacteria that grows in milk
• Overview: They’re (Almost) Everywhere!
• Most prokaryotes are microscopic
– But what they lack in size they more than
make up for in numbers
• The number of prokaryotes in a single
handful of fertile soil
– Is greater than the number of people who
have ever lived
• Prokaryotes thrive almost everywhere
– Including places too acidic, too salty, too cold, or too hot
for most other organisms
Figure 27.1
wall
(a)
Lipopolysaccharide
Peptidoglycan
layer
Cell wall
Outer
membrane
Peptidoglycan
layer
Plasma membrane
Plasma membrane
Protein
Protein
Grampositive
bacteria
Gramnegative
bacteria
20 m
(b)
Gram-positive. More peptidoglycan
Gram-negative. Less peptiodglycan
• Using a technique called the Gram stain
– Scientists can classify many bacterial species
into two groups based on cell wall composition,
Gram-positive and Gram-negative
• Some prokaryotes have fimbriae and pili
– Which allow them to stick to their substrate or other
individuals in a colony
Fimbriae
200 nm
Figure 27.5
Motility
Flagellum
Filament
50 nm
Cell wall
Figure 27.6
Hook
Basal apparatus
Plasma
membrane
• Most motile bacteria propel themselves by flagella
– Which are structurally and functionally different from
eukaryotic flagella
Chromosome
Figure 27.8
1 m
• The typical prokaryotic genome
– Is a ring of DNA that is not surrounded by a
membrane and that is located in a nucleoid
region
Reproduction and
Adaptation
Prokaryotes reproduce quickly by
binary fission
And can divide every 1–3 hours
Endospore
Figure 27.9
0.3 m
• Many prokaryotes form endospores(this is
why they can live anywhere!)
– Which can remain viable in harsh
conditions for centuries
Symbiotic Relationships
Figure 27.15
• Many prokaryotes
– Live with other organisms in symbiotic relationships such
as mutualism and commensalism
• Other types of prokaryotes
– Live inside hosts as parasites
Pathogenic Prokaryotes
• Prokaryotes cause about half of all human diseases
– Lyme disease is an example
Figure 27.16
5 µm
• Pathogenic prokaryotes typically cause
disease
– By releasing exotoxins or endotoxins
– Exotoxins – proteins released poisons the
cell.
– Endotoxins – parts of dead bacteria that
poisons the cell
• Many pathogenic bacteria
– Are potential weapons of bioterrorism
Organelles
Cytoplasm
Ribosomes
Nuclear Zone
DNA
Plasmid
Cell Membrane
Mesosome
Cell Wall
Capsule (or slime layer)
Flagellum
Eukaryotic Cells
Eukaryotic Cells
-possess a membrane-bound nucleus
-are more complex than prokaryotic
cells
-compartmentalize many cellular
functions within organelles and the
endomembrane system
-possess a cytoskeleton for support
and to maintain cellular structure
58
Eukaryotic Cells
59
Eukaryotic Cells
60
Eukaryotes are bigger and more
complicated
Have organelles
Have chromosomes
can be multicellular
include animal and plant cells
Organelles
Cytoplasm
Nucleus
Mitochondria
Chloroplast
Ribosomes
RER
SER
Golgi body
Vacuoles
Organelles
Lysosomes
Cytoskeleton
Centriole
Cilium and Flagellum
Microvilli
Cell membrane
Cell Wall
Organelles are
membrane-bound cell
parts
Mini “organs” that have
unique structures and
functions
Located in cytoplasm
How do animal cells
move?
Some can crawl with pseudopods
Some can swim with a flagellum
Some can swim very fast with cilia
Pseudopods
means “fake
feet”
extensions of cell
membrane
example:
ameoba
Flagellum/flagella
large whiplike tail
pushes or pulls
cell through water
can be single, or a
pair
Cilia
fine, hairlike
extensions
attached to cell
membrane
beat in unison
LifeStyles
Join with alike cells to form tissues
Tissues to form organs
Organs to form organ systems
Feeding
Autotrophic
Make own food - photosynthesis
Heterotrophic
Must obtain food
Carnivore
Herbivore
Omnivore
Detritivore
Eukaryote cells can be
multicellular
The whole cell can be specialized for
one job
cells can work together as tissues
Tissues can work together as organs
Advantages of each kind of
cell architecture
Prokaryotes
Eukaryotes
simple and easy to grow
can specialize
fast reproduction
multicellularity
all the same
can build large bodies
Examples of specialized
euk. cells
liver cell:
specialized to
detoxify blood
and store
glucose as
glycogen.
sperm cell:
specialized to
deliver DNA to
egg cell
Mesophyll
cell
specialize
d to
capture
as much
light as
possible
inside a
leaf
Cell Structures
Cell membrane
delicate lipid
and protein
skin around
cytoplasm
found in all
cells
Nucleus
a membrane-bound
sac evolved to store
the cell’s
chromosomes(DNA
)
has pores: holes
Nucleolus
inside nucleus
location of
ribosome
factory
made or RNA
mitochondrion
makes the
cell’s energy
the more
energy the cell
needs, the
more
mitochondria it
has
Ribosomes
build proteins from
amino acids in
cytoplasm
may be freefloating, or
may be attached
to ER
made of RNA
Endoplasmic
reticulum
may be smooth:
builds lipids and
carbohydrates
may be rough:
stores proteins
made by
attached
ribosomes
Golgi Complex
takes in sacs
of raw
material from
ER
sends out
sacs
containing
finished cell
products
Lysosomes
sacs filled with
digestive
enzymes
digest worn out
cell parts
digest food
absorbed by cell
Centrioles
pair of bundled
tubes
organize cell
division
Cytoskeleton
made of
microtubules
found throughout
cytoplasm
gives shape to cell
& moves
organelles around
inside.
Structures found in plant cells
Cell wall
very strong
made of
cellulose
protects cell
from rupturing
glued to other
cells next door
Vacuole
huge waterfilled sac
keeps cell
pressurized
stores starch
Chloroplasts
filled with
chlorophyll
turn solar
energy into
food energy
How are plant and animal cells different?
Structure
cell membrane
nucleus
nucleolus
ribosomes
ER
Golgi
centrioles
cell wall
mitochondria
cholorplasts
One big vacuole
cytoskeleton
Animal cells
Yes
Yes
yes
yes
yes
yes
yes
no
yes
no
no
yes
Plant cells
yes
yes
yes
yes
yes
yes
no
yes
yes
yes
yes
Yes