Journey Inside the CellJourney Inside the CellToday, we will:Today, we will:

Identify the role of the cell wall and cell Identify the role of the cell wall and cell membrane.membrane.

Explain the function of each organelle andExplain the function of each organelle and

Distinguish between plant and animal cellsDistinguish between plant and animal cells

and the differences between them.and the differences between them.

Show that cells are specialized for the Show that cells are specialized for the specific job they must dospecific 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 CellHere is a typical Plant Cell

http://waynesword.palomar.edu/lmexer1a.htm

Here is a typical Animal CellHere 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”.

OrganellesOrganelles

An An organelleorganelle is a tiny cell structure that is a tiny cell structure that carries out a specific function in the cell.carries out a specific function in the cell.

You can compare organelles in a cell with You can compare organelles in a cell with the organs in your own body. Just as your the organs in your own body. Just as your stomach, lungs, and heart have different stomach, lungs, and heart have different functions in your body, each organelle has a functions in your body, each organelle has a different function within the cell. 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 First check point, the Cell WallCell 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 Check Point Two, the Cell MembraneCell Membrane

We breezed through the cell wall with no We breezed through the cell wall with no problem, but the next barrier to a cell is a problem, but the next barrier to a cell is a bit more tricky…bit more tricky…

The The cell membranecell membrane controls what comes in controls what comes in and out of the cell. Everything a cell needs and out of the cell. Everything a cell needs comes in through the cell membrane; if comes in through the cell membrane; if something harmful would try to enter the something harmful would try to enter the cell, the cell membrane would stop it. cell, the cell membrane would stop it.

ALL cells have cell membranesALL cells have cell membranesIn cells with cell walls In cells with cell walls In other cells (animal In other cells (animal

(plant cells) the cell(plant cells) the cell cells), the cell membrane cells), the cell membrane

membrane is located justmembrane is located just forms the boundary that forms the boundary that

inside the cell wall. inside the cell wall. separates the cell from separates the cell from

These give plant cells theirThese give plant cells their its environment. its environment. Since they Since they havehave

box shape.box shape. no cell wall they have all kindsno cell wall they have all kinds

of shapes.of shapes.

Now that we have managed to get ourselves Now that we have managed to get ourselves past the cell membrane, we better report to past the cell membrane, we better report to the boss and let them know we are here!the boss and let them know we are here!

Off to the Off to the Nucleus…Nucleus…

WE’RE IN!

The The NucleusNucleusThe The nucleusnucleus is the cell structure that directs all the cells activities! is the cell structure that directs all the cells activities! It is found near the center of the cell.It is found near the center of the cell.

This is where the CHROMATIN (DNA) is found!This is where the CHROMATIN (DNA) is found!

The The nucleusnucleus is made up of three important parts: is made up of three important parts:

–The The nuclear envelopenuclear envelope which protects the nucleus. This is which protects the nucleus. This is often called the nuclear membraneoften called the nuclear membrane

-The -The chromatinchromatin which contains all the genetic information which contains all the genetic information for the cell (DNA). These are often called chromosomesfor the cell (DNA). These are often called chromosomes

-The -The nucleolusnucleolus is a structure where ribosomes are made is a structure where ribosomes are made (you will find out what ribosomes do later on!)(you will find out what ribosomes do later on!)

–All of these are floating in the protoplasm know as All of these are floating in the protoplasm know as NUCLEOPLASMNUCLEOPLASM

This is what a typical Nucleus This is what a typical Nucleus looks like.looks like.

http://www.emc.maricopa.edu/faculty/farabee/BIOBK/nucleus_1.gif

Remember, this is found near the center of the cell.

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.

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.

The The CytoplasmCytoplasm

Cytoplasm Cytoplasm is the region between the cell is the region between the cell membrane and the nucleus and is membrane and the nucleus and is protoplasm that is a clear, thick, gel-like protoplasm that is a clear, thick, gel-like fluid that is constantly moving.fluid that is constantly moving.

Many of the cell’s organelles can be found Many of the cell’s organelles can be found in the cytoplasm.in the cytoplasm.

The The OrganellesOrganellesFirst stop, are some rod-shaped structures right ahead!First stop, are some rod-shaped structures right ahead!These are the mitochondria.These are the mitochondria. MitochondriaMitochondria are known as the power houses of the are known as the power houses of the

cell. They look like hot dogs with ketchup on them.cell. They look like hot dogs with ketchup on them.

The The endoplasmic reticulumendoplasmic reticulum or or ER,ER, carries proteins and other carries proteins and other materials from one part of the cell materials from one part of the cell to another. to another.

Next, on to a maze of passageways…

They convert energy in They convert energy in food to ATP. This isfood to ATP. This is called RESPIRATION and will called RESPIRATION and will be discussed in your next chapter.be discussed in your next chapter.

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.

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.

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.

We now see green water balloons. These are called Chloroplasts.

Almost done…Almost done…

Look carefully around and see if you can Look carefully around and see if you can spot a small, round structure. This is a spot a small, round structure. This is a lysosomelysosome. . Lysosomes Lysosomes contain chemicals contain chemicals that break down certain materials in a cell.that break down certain materials in a cell.                 

The clean up crew of the cell.

Now that we are back, it is your job to compare Now that we are back, it is your job to compare plant and animal cells. What did we see in the plant and animal cells. What did we see in the plant cell that would not be found in an animal plant cell that would not be found in an animal cell? cell?

I hope you are able to tell me all 4 differences. Be I hope you are able to tell me all 4 differences. Be sure to include these in your notes. You will see sure to include these in your notes. You will see them again on the chapter test.them again on the chapter test.

Wow! What a great trip!