Download Journey Inside the Cell - CELL STRUCTURE AND FUNCTION UNIT

Journey Inside the Cell
Today, we will:
Identify the role of the cell wall and cell
membrane.
Explain the function of each organelle and
Distinguish between plant and animal cells
and the differences between them.
Show that cells are specialized for the
specific job they must do
We will first watch this short
video introducing you to the
cell
As you can see, this section has a
lot of new terms you need to get
to know. You should start now to
learn these terms and not wait
until the end of the chapter. We
will now start to present these
terms again, at a slower pace
than the video.
Here is a typical Plant Cell
http://waynesword.palomar.edu/lmexer1a.htm
Here is a typical Animal Cell
http://waynesword.palomar.edu/lmexer1a.htm
Although both cells looked similar, there are some
major differences between them. Pay close attention,
YOU will have to tell me these differences when
we finish our tour of the cell.
(HINT:These differences will be in yellow)
Right now, we are going to continue the trip, telling
you about all the structures that are found inside of a
cell. These structures are called “ORGANELLES”.
Organelles
An organelle is a tiny cell structure that
carries out a specific function in the cell.
 You can compare organelles in a cell with
the organs in your own body. Just as your
stomach, lungs, and heart have different
functions in your body, each organelle has a
different function within the cell.

All pictures of organelles are taken from cellsalive.com
Before we can go exploring the
inside of any cell, we have to go
through a security checkpoint.
First check point, the Cell Wall
Notice the cell wall – a rigid layer
of nonliving material that surrounds
the cells of plants and some other
organisms. Animal cells do NOT
have cell walls!
 A plant’s cell wall helps to protect and support the cell.
 It is made mostly of cellulose
 The cell wall is tough, but many materials can easily pass
through it (like water and oxygen)
Check Point Two, the Cell Membrane
We breezed through the cell wall with no
problem, but the next barrier to a cell is a bit
more tricky…
 The cell membrane controls what comes in
and out of the cell. Everything a cell needs
comes in through the cell membrane; if
something harmful would try to enter the
cell, the cell membrane would stop it.

ALL cells have cell membranes
In cells with cell walls
(plant cells) the cell
membrane is located just
inside the cell wall.
These give plant cells their
box shape.
In other cells (animal
cells), the cell membrane
forms the boundary that
separates the cell from
its environment. Since they have
no cell wall they have all kinds
of shapes.
WE’RE IN!

Now that we have managed to get ourselves
past the cell membrane, we better report to
the boss and let them know we are here!
Off to the Nucleus…
The Nucleus
The nucleus is the cell structure that directs all the cells activities!
It is found near the center of the cell.
This is where the CHROMATIN (DNA) is found!
The nucleus is made up of three important parts:
–The nuclear envelope which protects the nucleus. This is
often called the nuclear membrane
-The chromatin which contains all the genetic information
for the cell (DNA). These are often called chromosomes
-The nucleolus is a structure where ribosomes are made
(you will find out what ribosomes do later on!)
–All of these are floating in the protoplasm know as
NUCLEOPLASM
This is what a typical Nucleus
looks like.
Remember, this is found near the center of the cell.
http://www.emc.maricopa.edu/faculty/farabee/BIOBK/nucleus_1.gif
Some cells do not have a nucleus in their cells. We call these
types of cells PROKARYOTES. They do have nuclear
material, it is just not contained inside a nucleus.
Most cells have a nucleus. We call these types of cells,
EUKARYOTES.
Here is a short video on the difference between these two
types of cells.
The Cytoplasm
Cytoplasm is the region between the cell
membrane and the nucleus and is
protoplasm that is a clear, thick, gel-like
fluid that is constantly moving.
 Many of the cell’s organelles can be found
in the cytoplasm.

The Organelles
First stop, are some rod-shaped structures right ahead!
These are the mitochondria.
 Mitochondria are known as the power houses of the
cell. They look like hot dogs with ketchup on them.
They convert energy in
food to ATP. This is
called RESPIRATION and will
be discussed in your next chapter.
Next, on to a maze of passageways…
 The endoplasmic reticulum or
ER, carries proteins and other
materials from one part of the cell
to another.
On the ER, we saw some small, round like bodies attached to the
surface. These are called ribosomes. It is here that proteins are
made. Ribosomes may also be found just floating in the cytoplasm.
As we travel out of the passageways of the ER, we are
going to be checking out the structure that looks like
flattened sacs and tubes. These are the Golgi bodies.
The Golgi bodies receive newly formed “stuff” from the
ER, package it and then distribute it throughout the cell.
We now see green water balloons. These are called Chloroplasts.
Chloroplasts contain Chlorophyll which
capture energy from sunlight and use it to
produce food for the cell in a process called
PHOTOSYNTHESIS. This will be discussed
more in your next chapter. ONLY PLANTS
and some other organisms have
chloroplasts!
As we travel by the green chloroplasts,we bump into a
huge water filled sac.
This sac is called the vacuole. Vacuoles are storage areas
inside a cell. PLANT CELLS have extra large vacuoles.
Animal cells vacuoles are small.
Almost done…

Look carefully around and see if you can
spot a small, round structure. This is a
lysosome. Lysosomes contain chemicals
that break down certain materials in a cell.
The clean up crew of the cell.
Wow! What a great trip!


Now that we are back, it is your job to compare
plant and animal cells. What did we see in the
plant cell that would not be found in an animal
cell?
I hope you are able to tell me all 4 differences. Be
sure to include these in your notes. You will see
them again on the chapter test.