Understanding
Cell and Cell Theory
In
biology, cell material is studied in cell biology is called. Own cells was
discovered accidentally by Robert Hooke although by this time he simply
observed the dead cells from the tissue of cork. Therefore, he called cella or
empty space is then in English called the cell which then absorbed into
Indonesian as cells. Can you realize that the word cell, may seem a bad analogy
for a living creature's smallest functional. Just imagine, the room is empty,
even the room where the criminal was detained often referred to as a holding
cell. Well, but that's the reason, because Robert Hooke only observed an empty
cell death and to honor his discovery, so until now researchers have named
cells. So what is a cell? Understanding cell is of the duo best known
researchers that Schleiden and Schwann cells are on the theory that a
combination of several previous studies by some researchers of cells such as
Robert Virchow, H.J. Dut Rochet, Max Schultze, Robert Brown, Antony van
Leeuwenhoek. There are three theories duo cells of these researchers are:
1. All living organisms are composed of cells or cells.
An important definition of a cell is that it is a unit of protoplasm surrounded
by a thin plasma membrane. The protoplasm of all cells Contain a nucleus. The
rest of the protoplasm is called cytoplasm or cytosol. The cytoplasm contains
many cell organelles. This means that all living things are composed of either
a single cell (unicellular) or many (multicellular). Understanding cell main
thing is that each cell is a unit of protoplasm enveloped by plasma membrane
(thin membrane). Protoplasm in all living cells contain a nucleus or the cell
nucleus. Aside from the cell nucleus, cytoplasm contained in the cell or can be
called cytosol. In the cytoplasm of cells, there are some cell organelles.
2. Cell
are the functional unit of life. That is, the cells are functional units in
living things. Every living creature in this world until now arrayed by the
cell or cells so that it can carry out character traits as living beings. Cells
in multicellular organisms interact with each other and work together to form
tissues and then form organs and so on up into the individual unit of living
things. Whereas in single cells, organelles of the cell organelles perform
their roles efficiently and controlled by the cell nucleus (nucleus) in order
to carry out the character as living beings (described in more detail later)
and every kind of unicellular and not even able to do the kind of communication
and interaction.
3. Each
Arise cells from pre-existing cells. That is, each cell that has been present
there due to the cells forming. The above sentence describes the cells' ability
to multiply or divide either sexually or asexually parasexual. This capability
makes the existing cells capable of sustainable. It still supports the theory
that modern abiogenesis their protobion before then presenting cells such as
cells that you see today. The above statement does not justify the theory of
biogenesis, so you do not misunderstand that the three above cell theory states
that all cell types have been there before. Not at all, the theory of evolution
to justify the above cell and directs the cell to the cell's ability to
reproduce themselves. In addition, the third cell theory also explains about
the ability of certain cells to perform a fusion or merger as in the egg and
sperm to form a zygote, and the ability of the cells to other cells such as
diploid cell into four haploid cells in spermatogenesis.
Based
on the theory of the cell by Schwann and Schleiden above, it can be concluded
that the definition of a cell is
“The cell is the functional unit of life that
is a constituent of living beings or living beings composed of protoplasm
surrounded by a thin membrane and is able to reproduce itself either sexually
or otherwise so as to form daughter cells either identical or not.”
Based
on the understanding of cells above, it is clear that some of the findings
today such as viruses and prions his comrades also not a living thing because
not fit with the notion of cells above. If the virus is said to be an absolute
cell then already, the virus is a living creature. So, you do not say
"cell virus" Well, enough virus alone.
Various kinds of cells (Brief)
Before
more in discussing about the cell, the cell structure and cell organelles, let
us know briefly kinds of cells that exist today. Broadly speaking, the cell is
divided into two based on the presence or absence of nuclear membrane is a
eukaryotic cell (having nuclear membrane) and prokaryotes (does not have a
nuclear membrane). This is broadly split all branches of living things that we
know today. Starting from archaebacteria, bacteria and eubacteria (all living
organisms other than bacteria and archaebacteria).
Furthermore, cells divided more specifically into cells
unicellular animals (protozoa), unicellular algae cells, cell fungi (hyphae),
plant cells, multicellular animal cells, bacterial cells, cell archaebakteria,
and various types of cell differentiation that exists. Overall there are cells
that are all tailored to the habitat they are and they need to remain
sustainable.
Definition and Structure of Cells
In
this article we'll describe 4 + 1 kind of cell structure that exists is the
structure of multicellular animal cells, plant cell structure, cell structure
unicellular animals (protozoa), the cell structure of bacteria, and the last
structure of unicellular algae cells.
Understanding the structure of the cells
of multicellular animals
You
know what that make up your body? It is animal cells together to form tissues,
and organs and organ systems and be human. Understanding animal cells are cells
that have the protoplasm and the cell membrane but does not have a cell wall as
well as the ability to photosynthesize, besides understanding animal cell is a
cell that is heterotrophic organisms and does not have a cell wall.
The
structure of animal cells are generally composed of cell membranes and
protoplasm. Animal cell protoplasm there is cytoplasm and nucleus of the cell
(nucleus) as well as cell nuclei or nukleoulus child. In the cytoplasm of
animal cells, there are several organelles such as ribosomes, mitochondria,
lysosomes, smooth and rough endoplasmic reticulum, Golgi apparatus / Golgi
apparatus, centrioles, peroxisomes. Animal cells, as described in the above
definition of animal cells, lack a cell wall but has called the extracellular
matrix sheath cells.
Definition and structure of plant cells
Drafting
a variety of plants that you saw yesterday and today, is composed of cells of
plant cells which then form a network of plants. Understanding plant cells are
cells that have protoplasm, cell membrane and cell wall composed of cellulose
(or hemi-cellulose) and chloroplasts in the cytoplasm so that it can carry out
photosynthesis. Understanding plant cells from the other side is a cell that is
capable of forming his food and energy with the help of light energy or
photoautotrophs with the help of chloroplasts and chlorophyll.
The
cell structure of plants ranging from the outside, you can find their cell
walls are thick but has little slits where the entry of substances needed,
after all, it is their cell membranes. The cell membrane is the same with animal
cell membranes, composed of a phospholipid bilayer. Then organelle organelles
similar to animal cells will be found in plant cells (except centrioles which
only exist in plant cells are motile). In addition, you can see the vacuoles in
animal cells and many small but in plant cells generally only amounted to one
and a large and located amid the so-called central vacuole.
To
find out more about the structure of animal cells and plant cell structure, and
the difference between these two cells, please read some of the articles below:
- Animal cells: Structure and function of cell organelles animals
- Plant cells: eukaryotic cells with cell walls
- The cell membrane: structure, Authors and nature
- Plant cell walls
- Organelles and cell membranes
- Differences in plant cells and animal
cells in a table
Definition and Structure of
a bacterial cell
Definition
of simple bacterial cells are cells that are in a group prokaryotes.
Understanding the bacterial cell is a cell that is walled cell but does not
have a nuclear membrane and organelles except ribosomes and other organelles
mesosom (organelles while).
Although
the structure of the bacterial cell has a cell wall but different cell wall
constituent of plant cell. The difference lies in the content of peptidoglycan
in the cell wall of bacteria. Differences in the amount of peptidoglycan in the
bacterial cell wall makes it formed two kinds of bacteria are gram-negative and
gram-positive bacteria.
Bacterial
cells have a variety of forms ranging from cocci (round), rods (bacilli) and
spiral. One thing you have to emphasize the bacterial cells are, bacterial
cells do not have a nuclear membrane so that the cell nucleus dispersed in the
cytoplasm.
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