Cell Structure and Function

Cell Structure and Function

In this section of Cell Structure and Function I learned about all the
different kinds of cells, everything that makes up a cell and their
functions. I also learned a little history first, about where the cell
was first described and named.

First I want to talk about the two major types of cells we learned
about, which are the Prokaryotic and Eukaryotic cells. The Prokaryotic
cells are found in bacteria, while the Eukaryotic cells are found all
other forms of life, like animals, plants, and fungi. The Prokaryotic
cells are very different in structure from the Eukaryotic cells. For
instance, in Prokaryotic cells the DNA is not enclosed by a
double-walled nuclear membrane, which means they don't have a true
nucleus. In the Prokaryotic cells the DNA is concentrated in a nuclear
dense zone called the nucleoid and there is no defined it membrane to
separate the nuclear material. Most Prokaryotic cells have tough
external cell wall, as in plants and fungi which are made up of
Eukaryotic cells. The compositions of the cell wall differ from each
other kind of cell. In a plant cell wall there is three parts, primary,
secondary, and middle lamella. Animal cells do not have a cell wall. The
Prokaryotic cells are a lot simpler compared to the Eukaryotic cells.
Eukaryotic cells contain organelles that are separated by membranes.
These organelles form different departments which include the
mitochondria, chloroplasts, peroxisomes, nucleus endoplasmic reticulum
and golgi. The major differences in Prokaryotic and Eukaryotic cells is
that in Eukaryotic cells there is a true nucleus, and the soup that lies
between the nucleus and plasma membrane is the cytoplasm called cytosol,
which suspends the membrane- bound organelles.

There are three types of cells made from Eukaryotic cells which are
plant, animal, and fungi cells. Within the three different types of
Eukaryotic cells there are many different components that make up an
animal cell, that differ from plant and fungi. This basically means that
even though there are three different types of cells classified under a
Eukaryotic cell, each cell differs from each other because there not all
made up of the same organelles. For example although plants do, animals
don't have a central vacuole, tonoplast, chloroplasts, plasmodesmata, or
even a cell wall; likewise, plant cells don't contain lysosomes,
centrioles, or flagella.

In contrast to learning the differences between Prokaryotic and
Eukaryotic cells or even the difference between animal and plants cells
we learned how they contain many of the same comparable organelles. For
example every cell has an plasma membrane or cell envelope, which is
also known as the 'plasmalemma', which is a definite boundary that's
picky what it lets in, like molecules. Then we learned about the
nucleus, another organelle that animals and plants like both has, which
is the control room of the cell. The nucleus is where the 23 paired
chromosomes are enclosed, which transcribes a section into RNA, which in
turn uses ribosome's as the site of protein synthesis where RNA is
translated. Then there is the endoplasmic reticulum (ER), which is the
largest membrane in the cell; this organelle splits into two distinct
regions, rough ER-its not functioning properly if you get sick, and
smooth ER. We also learned about the Golgi apparatus, which is just like
a post office, everything is sent to it first to then be sent out to
different places. Then there is the garbage man who is played by
lysosomes in animals and the central vacuole in plants, which gets rid
of the bad and even destroys it-self as a cell if malfunctions. Then
there the mitochondria, the power house, which is the chloroplast in
plants. So even though animals and plants or Prokaryotic and Eukaryotic
cells may differ in many ways, they are very much alike in a number of
common organelles, and even the organelles they differ in they have a
common function.