Transcript CELL

Prokaryotic Cells Vs.
Eukaryotic Cells
Now that we have learned how living
things are organized what’s next?

We will learn more about the lowest level
of organization: cells
What is the first thing that we need to know
about cells?
 All cells fall into one of the two major
classifications of either prokaryotic or
eukaryotic.
What’s the difference between
prokaryotes and eukaryotes?

Prokaryotic cells were here first and for
billions of years were the only form of life
on Earth. All prokaryotic organisms are
unicellular

Eukaryotic cells appeared on earth long
after prokaryotic cells but they are much
more advanced. Eukaryotic organisms
unlike prokaryotic can be unicellular or
multicellular.
Glow in
the
dark
squid…
how
does it
do
that?




Vibrio
fischeri
Glow in
the dark
bacteria
Helps it
survive in
the ocean
Lives in
fish and
other
marine
life
Let’s Take a Look at the
Characteristics of Prokaryotes

Prokaryotes are the simplest type of cell.

Oldest type of cell appeared about four billion
years ago.

Prokaryotes are the largest group of organisms

Prokaryotes unicellular organisms that are found
in all environments.
Let’s Take a Look at the
Characteristics of Prokaryotes

Prokaryotes do not have a nuclear membrane .
Their circular shaped genetic material dispersed
throughout cytoplasm.

Prokaryotes do not have membrane-bound
organelles .

Prokaryotes have a simple internal structure.

Prokaryotes are smaller in size when compared
to Eukaryotes.
Shapes of Prokaryotes
Cocci =
spherical
(round)
 Bacillus =
(rod
shaped)
 Spirilla =
helical
(spiral)

What do prokaryotic cell look
like?
Now let’s take a look at the
characteristics of eukaryotes

Eukaryotic cells appeared approximately
one billion years ago

Eukaryotes are generally more advanced
than prokaryotes

Nuclear membrane surrounds linear
genetic material (DNA)
Is there more? Yes!!!

Unlike prokaryotes, eukaryotes have several
different parts.

Eukaryote’s organelles have coverings known
as membranes.

Eukaryotes have a complex internal structure.

Eukaryotes are larger than prokaryotes in size .
What do eukaryotic cells look
like?
Mitochondria
Nucleus
Cytoplasm
Golgi
Complex
Endoplasmic
Reticulum
Cell
Membrane
How do the differences line up?
Prokaryotes
 Organelles lack a
membrane
Eukaryotes
 Organelles covered
by a membrane

Ribosomes are the
only organelles

Multiple organelles
including ribosomes

Genetic material
floats in the
cytoplasm (DNA and
RNA)

Membrane covered
Genetic material
How do the differences line up?
Prokaryotes
 Circular DNA
Eukaryotes
 Linear DNA

Unicellular

May be multicellular
or unicellular

Cells are smaller in
size

Cells are larger in
size

Has larger number of
organisms

Has smaller number
of organisms
How do the differences line up?
Prokaryotes
 Appeared 4 billion
years ago
Eukaryotes
 Appeared 1 billion
years ago
How do the similarities line up?
Lets See!!!




Both types of cells have
cell membranes (outer
covering of the cell)
Both types of cells have
ribosomes
Both types of cells have
DNA
Both types of cells have a
liquid environment known
as the cytoplasm
Your turn:
 Make a Venn Diagram outlining the
similarities and differences between
prokaryotes and eukaryotes

You may use your book and/or consult
your teammate
Robert Hooke


Used a compound
microscope and
viewed a slice of cork.
He saw little box
structures and called
them cells. He used
this name because it
reminded him of little
rooms that monks lived
in.
Anton Van Leeuwenhoek


Was the first to see
living organisms and
called them
animalcules.
Used the first simple
light microscope.
Matthias Schleiden

First to see living plant
cells and determined
that plants are also
made of these tiny
structures called cells.
Theodor Schwann

Viewed animal tissue
and concluded that
animals are also made
of these tiny structures
called cells.
Rudolf Virchow

He was the scientist
that said cells can only
be produced by other
living cells.
The Cell Theory
1.
2.
3.
All Organisms are composed of one or
more cells.
The cell is the basic unit of structure and
organization of organisms.
All cells come from other living cells.
Cells
Organelles are
membrane-bound cell
parts
Mini “organs” that have
unique structures and
functions
 Located in cytoplasm

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 free-floating,
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 water-filled
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
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
What do all these have in common?
Specialized Cells
Learning Objectives:
Learning Activities:
1. All must be able to
1. What is the picture?
describe with examples,
2. Discuss what is a
how cells are specialised
specialised cell
to perform different
3. Powerpoint showing
functions.
different specialised cells
2. Most should be able to
4. Worksheet
state how cells group
5. Quiz on plant and animal
together to form tissues.
cells
3. Some could state how
specific cells are adapted
to their function.
WHAT IS A SPECIALIZED CELL?
 Plants
and animals consist of many cells and
so are known as multicellular
 They contain many different types of cells.
 Each type of cell is designed to carry out a
particular job or function.
 This is known as cell specialism
 Not all cells look the same.
 Some cells have a special shape and features
to help them do a certain job.
SPERM CELL
Head contains enzymes & nucleus
Designed to Fertilise eggs.
Found in the Testes
Tail
A sperm is small and has a long
tail that provides movement so it
can swim and find an egg cell.
The head contains enzymes
which allow it to digest into an
egg cell and join with it.
EGG (OVUM) CELL
Cytoplasm containing yolk
 Designed
 Found
to be Fertilised.
in the Ovaries.
 An
egg cell is large and
bulky.
 Contains
Layer of jelly
Nucleus
yolk which
provides a large food store
for the new cell being
formed.
PALISADE CELL
 Designed
for
Photosynthesis
 Found
Nucleus
in the top of a leaf
 Tall
and has a large
surface area to absorb
water and minerals.
 Packed
with chloroplasts to
help make plant food.
Chloroplasts
CILIATED CELL
Nucleus

Designed to stop Lung
Damage

They line all the air
passages (trachea, bronchi
& bronchioles) in the lungs.

They have tiny hairs called
cilia.

Hairs sweep mucus with
trapped dust and bacteria
back up the throat.
cilia
ROOT HAIR CELL
Designed for absorbing.
Vacuole
•Thin cell wall
makes it easy
for minerals to
pass through.
thin cell wall
•Has a large
surface which
helps it to
absorb water
and minerals.
Cell membrane
•Found in a plant root.
NERVE CELL (NEURONE)
Nucleus
•They are long
•They have connections at each end
•Can carry electrical signals
•Their job is to carry nerve impulses to different
parts of the body.
RED BLOOD CELL
•Designed to carry oxygen
•Found in blood.
•Large surface area, for oxygen to pass through.
•Contains haemoglobin, which joins with oxygen.
•Has no nucleus
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
