Hello everyone! Welcome to the “Building
Blocks of Life” tour. As some of you may know, all living things are made up of
these tiny things called cells. Cells themselves are so small that in order to
see them you have to use a microscope.Did everyone get their tour passes at the
front desk? It’s very important you have them handy for going through the cell
membrane. The cell membrane is the outer wall of the cell. It determines what
should be allowed into the cell and protects the cell from its surroundings.
Everyone needs their tour passes so the cell membrane will let you in.
Now that we’ve made it inside the cell, I
must warn you to keep an eye out. What we are walking through is called the
cytoplasm. It’s the material that contains the cell structure on the inside but
also allows all of the organelles, or parts of the cell, to move around. This
means that the organelles are going to continue moving and may not stay in the
same place at all times so we must be careful not to interfere with their work
or get hurt. Speaking of which, there is a lysosome passing in front of us
right now. The lysosome has the job similar to a garbage truck. It breaks down
and absorbs materials that are taken in by the cell that should not have been.
It’s a second defense beyond the cell membrane to make sure that the cell stays
healthy. From the moment organelles are formed in the cell, they work nonstop
performing their specialized roles. Due to this they become exhausted and
eventually stop working how they are supposed to. It’s the lysosomes job to
absorb the nonfunctioning organelle so that a new one can be made. Exocytotic
vesicle are similar to the lysosomes in some aspects. They are the dump trucks
of the cell. Exocytotic vesicles remove the waste found inside of the cell by
ejecting or “dumping it” outside of the cell.
It looks like the lysosome might be doing
just that with the mitochondria. A healthy mitochondria is like the bank of the
cell. It is where ATP is released. ATP is the energy the cell needs to do its
job. It is similar to us needing breakfast in the morning so we can start our
day off right. ATP is then used as a type of money. Organelles then “withdraw”
the ATP from the mitochondria so that they can do their functions properly.
While we go to the bank to withdraw twenty dollars so we can get a special
lunch, other organelles withdraw ATP so that they can have their version of
“lunch” and continue to work to earn more ATP.
Our next stop is the Golgi apparatus or as
it is sometimes called, the Golgi body. The Golgi apparatus is the organelle in
which ribosomes are in the finishing process of being made. Ribosomes are working
force behind building and making proteins for the cell. These proteins are
required to help repair damage in the cell as well as directing the chemical
processes within the cell. The Golgi apparatus makes the finishing touches on
the ribosomes by tweaking them slightly and performing quality control. After
the Golgi apparatus approves a ribosome, the Golgi apparatus then sends it to
other organelles that need the ribosome. In this sense, the Golgi body is
similar to UPS. It checks over the incoming mail, ribosomes, approves or
adjusts them, packages the incoming mail, and then ships it to its new destination.
From here, we will be going to the
endoplasmic reticulum or “ER” for short. There are two types of endoplasmic
reticulum: smooth and rough. They are named by their textures. The ER are the
designated location for the ribosomes to do their work before being sent off to
the Golgi apparatus. The rough ER has the perfect texture for ribosomes to
latch on to so proteins can be built with more stability. The smooth
endoplasmic reticulum produces steroids and can regulate calcium levels in
order to promote ribosome efficiency as well as cell performance as a whole.
The organelle to our left is called a
vesicle. It is similar to a Tupperware container. It holds and seals in
enzymes. Vesicles are also used as a transportation vehicle. As mentioned
before, the Golgi body preforms the logistics of the shipping process. In this
aspect, vesicles are the mailmen who deliver packages to your door.
Our last stop
today is the nucleus. The nucleus is the scientific headquarters of the cell.
It is protected by the nuclear membrane which is a similar, smaller version of
the cellular membrane and covered with nuclear pores which determine what can
and cannot exit the nucleus. Inside the nuclear membrane is the nucleolus. This
is where all the blueprints, executive offices, and scientific laboratory are
located. The nucleolus is the fingerprint of the cell. It determines what type
of cell it is whether that be a muscle cell, skin cell, blood cell, or any
other cell. This knowledge allows the rest of the cell to know what its purpose
is such as a blood cell would have the purpose of bringing oxygen to other
cells in need. Along with its identity, the nucleolus has the blueprints for
cellular production. There are two types of blueprints. DNA are the
instructions to rebuild the cell as a whole including all of the organelles and
RNA are the instructions to build proteins. Cells reproduce by themselves using
one of two methods depending on what type of cell it is. These methods are
mitosis and meiosis. Although they are two different processes, they are
composed of the materials: DNA, centrioles, and spindle fibers. Centrioles and
spindle fibers are used to help separate the DNA during the duplication process
in cell reproduction so that new cell is an identical copy.
It is important to note that every organelle is
directly connected to another. If one begins to not function properly, the
entire cell will reflect the defect. It is a microscopic city with each organelle
doing its job for the wellbeing of the community from regulating who enters and
exits, removing waste, shipping and receiving packages of proteins, exchanging
energy currency, and managing the entire operation. Now that you have learned
the basic functions inside an organelle, you all can now move on to the next,
but related exhibit, “Mitosis and Meiosis: What’s the Difference?”
