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Looking Inside Cells
Enter the Cell
As you enter a cell you must first slip through the CELL WALL. This is a rigid
layer of nonliving material that surrounds the cells of plants and some other organisms.
The cells of animals, in contrast do NOT have cell walls. A plant’s cell wall helps to
PROTECT and SUPPORT the cell.
After you have passed the cell wall the next layer you must pass is the CELL
MEMBRANE. All cells have cell membranes. In cells with cell walls, the cell
membrane is located just inside the cell wall. In other cells, the cell membrane forms the
OUTSIDE BOUNDARY that separates the cell from its ENVIRONMENT. The cell
membrane CONTROLS what substances come into and out of the cell. The cell
membrane is like a window screen. It allows what the cell needs such as FOOD and
OXYGEN to pass in. The cell membrane also allows waste products to leave the cell.
Sail on to the Nucleus
A large oval structure called the NUCLEUS acts as the “brain” of the cell. The
nucleus is the cells control center, which controls all the cell’s activities. The nucleus is
surrounded by the NUCLEAR ENVELOPE. This membrane allows materials to pass in
and out of the nucleus through PORES in the nuclear envelope. Inside the nucleus are
thousands of thin strands called CHROMATIN which contain the genetic
material/instructions for directing the cells functions. A small structure within the
nucleus called the NUCLEOLUS is where ribosomes are made.
Organelles in the Cytoplasm
Outside the nucleus but inside the cell membrane is a region called
CYTOPLASM. This is a clear, thick, gel-like fluid. The fluid in the cytoplasm is
CONSTANTLY MOVING. Many cell organelles are found in the cytoplasm. Within
the cytoplasm are rod-shaped structures called MITOCHONDRIA. These organelles are
known as the POWER HOUSES of the cell because they convert energy in food
molecules to energy the cell can use to carry out its FUNCTIONS.
Another organelle in within the cytoplasm is the ENDOPLASMIC RETICULUM.
This looks like a maze of passageways. The endoplasmic reticulum’s passageways
CARRY PROTEINS and other materials from one part of the cell to another. Attached to
some surfaces of the E.R. are small , grainlike bodies called RIBOSOMES. Some other
ribosomes float freely within the cytoplasm. These tiny organelles function as factories
TO PRODUCE PROTEINS. Outside the E.R. is what looks like flattened sacs and tubes.
This structure is called a GOLGI BODY. The golgi body can be thought of as the cells
MAIL ROOM. It receives PROTEINS and other newly formed materials from the E.R.,
packages them, and distributes them to other parts of the cell.
CHLOROPLASTS are large green structures floating in the cytoplasm. Only
plant cells and some other organisms have chloroplasts. These chloroplasts CAPTURE
ENERGY from sunlight and use it to produce food for the cell.
VACUOLES are large storage areas of a cell. Most plant cells have one large
VACUOLE; and some animal cells do not have vacuoles. They STORE FOOD and
other materials needed by the cell. Vacuoles can also store WASTE PRODUCTS.
The last organelle within the cytoplasm are LYSOSOMES. These are small,
round structures containing CHEMICALS that break down certain materials in the cell.
These small organelles can be thought of as the cells CLEANUP CREW because they
breakdown food and old cell parts, then release the substances to be used again.
Looking Inside Cells
Enter The Cell
As you enter a cell you must first slip through the __________ _________. This
is a rigid layer of nonliving material that surrounds the cells of plants and some other
organisms. The cells of animals, in contrast do _____ have cell walls. A plant’s cell wall
helps to _______________ and ____________ the cell.
After you have passed the cell wall the next layer you must pass is the ________
_______________. All cells have cell membranes. In cells with cell walls, the cell
membrane is located just inside the cell wall. In other cells, the cell membrane forms the
_____________ _____________ that separates the cell from its ________________.
The cell membrane ______________ what substances come into and out of the cell. The
cell membrane is like a window screen. It allows what the cell needs such as ________
and __________ to pass in. The cell membrane also allows waste products to leave the
cell.
Sail on to the Nucleus
A large oval structure called the ____________ acts as the “brain” of the cell.
The nucleus is the cells control center, which controls all the cell’s activities. The
nucleus is surrounded by the _____________ ______________. This membrane allows
materials to pass in and out of the nucleus through ________ in the nuclear envelope.
Inside the nucleus are thousands of thin strands called _______________ which contain
the genetic material/instructions for directing the cells functions. A small structure
within the nucleus called the _________________ is where ribosomes are made.
Organelles in the Cytoplasm
Outside the nucleus but inside the cell membrane is a region called
________________. This is a clear, thick, gel-like fluid. The fluid in the cytoplasm is
_______________ _______________. Many cell organelles are found in the cytoplasm.
Within the cytoplasm are rod-shaped structures called ___________________. These
organelles are known as the ___________ ____________ of the cell because they convert
energy in food molecules to energy the cell can use to carry out its _________________.
Another organelle in within the cytoplasm is the _________________
____________________. This looks like a maze of passageways. The endoplasmic
reticulum’s passageways ____________ ___________ and other materials from one part
of the cell to another. Attached to some surfaces of the E.R. are small , grainlike bodies
called _____________. Some other ribosomes float freely within the cytoplasm. These
tiny organelles function as factories __________________________. Outside the E.R. is
what looks like flattened sacs and tubes. This structure is called a _________ ________.
The golgi body can be thought of as the cells _________ ________. It receives
____________ and other newly formed materials from the E.R., packages them, and
distributes them to other parts of the cell.
_________________ are large green structures floating in the cytoplasm. Only
plant cells and some other organisms have chloroplasts. These chloroplasts ___________
___________ from sunlight and use it to produce food for the cell.
______________ are large storage areas of a cell. Most plant cells have one large
________________; and some animal cells do not have vacuoles. They __________
_________ and other materials needed by the cell. Vacuoles can also store __________
_______________.
The last organelle within the cytoplasm are ______________. These are small,
round structures containing ______________ that break down certain materials in the
cell. These small organelles can be thought of as the cells _____________ ________
because they breakdown food and old cell parts, then release the substances to be used
again.