CELL STRUCTURE NOTES
The following are the main structural components of cells. Fill in the blanks during
the PowerPoint slide show. Then learn their names and the function of each of
them:
CELL MEMBRANE
1.
Cell Membrane:
a.
Found in all cells.
b.
Composed of two layers of lipid molecules known as the __________
________________________ Since these molecules don’t mix well
with _______________________, they help to control the movement
of water in and out of cells.
c.
Embedded within the lipid bilayer are _________________________.
They serve as channels allowing water and other substances to get in
and out.
d.
_______________________________________ molecules are often
found near the protein channels and they help to identify substances.
They function like chemical _________________________________,
so that only certain things are permitted to enter the cell.
2.
Cell Wall:
a.
Found only in ____________________________________________.
b.
The cell wall gives support to the plant cells.
Continued on the back page
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c.
One of the molecules making up the cell wall is _________________.
Cellulose is very porous and elastic. Large plants, like trees, have
another molecule, ___________________________, in their cell
walls. Together, cellulose and lignin give a great deal of support to the
tree.
d.
Finally, __________________ is a sticky substance found on the
outside of the cell walls. It acts like a glue, helping to keep the cell
walls together.
NUCLEUS
1.
Nuclear Envelope (Membrane):
a.
Found only in ________________________ cells (plants and animals)
b.
This structure acts very much like the cell membrane. It has pores in it
that regulates what can enter and leave the nucleus.
2.
Nucleolus:
a.
Also found only in eukaryotic cells.
b.
The nucleolus assists in manufacturing ________________________,
an organelle that makes proteins. Since proteins are the most
important group of molecules in your body, controlling the production
of ribosomes has the effect of controlling what proteins are made.
This in turn controls the function of the entire cell.
3.
Chromatin:
a.
Found in all cells.
b.
Chromatin, which sometimes condenses into structures called
___________________________________, is made up of _________
and ______________________________.
c.
DNA carries the genetic code, the set of instructions which tells the
cell what to do.
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d.
Chromatin also plays an important part in passing on genetic
information to future generations.
CYTOPLASM
Found in all cells, the cytoplasm is defined as the area between the _____________
and the __________________________________________. Found within the
cytoplasm are various organelles:
Organelles that Capture and Release Energy:
1.
Mitochondria:
a.
Found in both plant and animal cells.
b.
Known as the “_______________________________” of the cell.
The mitochondria change the chemical energy stored in food particles
into a more useful form of energy through a process known as
___________________________________________.
c.
Mitochondria have two membranes. The inner membrane has many
folds to increase its surface area. The more mitochondria a cell
contains, the more _____________________________ it can produce.
d.
Mitochondria contain their own small ____________ molecules, all of
which, in humans, was inherited only from your _________________.
2.
Chloroplasts:
a.
Found only in plant and algae cells.
b.
Similar in structure to the mitochondrion, chloroplasts trap the energy
in sunlight and converts it to chemical energy
(________________________________).
c.
Chloroplasts also contain a small amount of ___________________.
Organelles that Build Proteins:
3.
Ribosomes:
a.
Found in both plant and animal cells.
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b.
Ribosomes are the structures in which ________________________
are made.
c.
Some ribosomes are floating free in the cytoplasm, while other
ribosomes may be attached to the endoplasmic reticulum.
4.
Endoplasmic Reticulum (ER):
a.
Found in both plant and animal cells.
b.
The ER is the organelle where components of the _______________
___________________________ and some ___________________
are assembled. It also assists with ___________________________
within the cells.
c.
There are two types of ER: _________________________________.
Rough ER has ribosome’s stuck to it.
5.
Golgi Apparatus:
a.
Found in both plant and animal cells.
b.
Resembling a stack of pancakes, the Golgi Apparatus attaches
_____________________________ and _______________________
to _______________________________. This helps to improve the
function of these molecules.
Organelles that Store, Clean Up, and Support:
6.
Lysosomes:
a.
Found only in _________________________ cells, not in plant cells.
b.
Lysosomes are responsible for __________________________
___________________________________________________
c.
7.
Produced by the Golgi Apparatus, lysosomes also break down
organelles that are no longer functioning or needed. Think of them as
the _______________________________________ of the cell!
Vacuoles:
a.
Found in all cells, but particularly large in plant cells.
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b.
Vacuoles are ____________________________________ containers
in the cell. They store water, salts, proteins, and carbohydrates.
c.
In many plant cells, a large vacuole, filled with __________________,
can be found. This helps to give support to the cell and the plant
8.
Plastids (Vesicles):
a.
Found only in plants.
b.
Chloroplasts, which were discussed earlier, are one form of plastids.
Many plastids store ________________________________________.
c.
Leukoplasts, found in potatoes, store _________________ molecules.
d.
Chromoplasts store
pigment molecules. The red color found in
____________________________ comes from pigments found in the
chromoplasts.
9.
Cytoskeleton:
a.
Found in both plant and animal cells.
b.
The cytoskeleton is made of a variety of filaments and fibers that
supports the cell or helps it to move about.
c.
There are two main parts of the cytoskeleton:
1.
Microtubules:
a.
These are hollow tubes made of ____________________.
They provide support for the cell’s shape and form the
centrioles.
b.
Centrioles are found in animal cells, but not in plant cells.
They play an important role in _____________________.
c.
In some cells, the microtubules form cilia or flagella.
___________________ are short, thread-like structures
found around the outside of the cell. They serve like little
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legs (like on a millipede) that helps the cell move.
_________________________________ are longer
whip-like structures. They serve like a tail that whips
back and forth, moving the cell along.
2.
Microfilaments:
a.
These are long, thin fibers found in the cytoplasm.
b.
They help ____________________________________
____________________________________________
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