Nucleus of a Eukaryotic Cells:
The Nucleus of a Eukaryotic cell contains the DNA, which is the genetic material of
a cell. The DNA has a big importance when it comes to the construction of a cell.
The DNA contains the information needed for constructing a cell and directing the
multitude of synthesis tasks a cell must carry during the process of life and
reproduction.
The nucleus has as a function being the brain of the cell, it directs cell activities and
contains the genetic material also called chromosomes which are made of DNA.
Nuclear Envelope:
A nucleus contains a nuclear envelope or also called nuclear membrane. This
membrane is divided into outer nuclear membrane and inner nuclear membrane, it
surrounds the nucleus with multiple pores.
Nuclear Pores:
This pores are used to regulate the passage of macromolecules such as proteins
and RNA, however these pores allow the free passage of water, ions, ATP as well
as other small molecules. Through this way the membrane is able to exert control
over the flow of information in the cell due to the fact that information is carried by
the macromolecules. These pores have a geat impact as well on how the cell ends
up looking and doing as they control what comes in adn out.
Chromatin:
Inside the nucleoplasm, between the nucleolus and the membrane, chromatin can
be found wrapped around histone proteins. A histone protein can be defined as
“any of various simple water-soluble proteins that are rich in the basic amino
acids lysine and arginine and are complexed with DNA in the nucleosomes of
eukaryotic chromatin” Chromatin contains the organism`s genome, which is the
collection of all the genes. This chromatin is composed of a compound names
deoxyribonucleic acid, or DNA which is associated with proteins which allows the
formation of long strands also called chromosomes. The DNA of the cell remains in
the nucleus, therefore it controls most of the processes that occur in the cytoplasm
of the cell. The information from the DNA may be transcribed to mRNA and then be
transmitted into other cellular synthesis processes. The information generated in
the cytoplasm can provide feedback again to the nucleus.
Nucleolus:
The nucleolus is located in the central part of the cell nucleus, this is the one
composed of ribosomal RNA, proteins and DNA. The nucleolus produces
ribosomes, which move out of the nucleus in order to take positions on the rough
endoplasmic reticulum where they accomplish the process of protein synthesis. In
various stages of synthesis ribosomes may also be contained. The nucleolus
completes the function of accomplishing the manufacture of ribosomal RNA which
are then transmitted to the chromatin as DNA. The nucleolus is the place where
ribosome synthesis occurs. Ribosomes, RNA (large complexes of protein and
ribonucleic acid) are in charge of the protein synthesis.
The process followed in order to complete the protein synthesis is the following: the
DNA inside the nucleus is being copied into small strands of RNA which then form
the chromatin, these mRNA molecules are then transported about of the nucleus
through the nuclear pores in the membrane and go into the cell`s cytoplasm where
they eventually are translated into proteins thanks to ribosomes.
In other words: DNA---RNA---finally=PROTEIN
The scale of the model compared to the real one is:
0.1mm is the actual size
300mm model size
300mmx1000/100micrometres=30000xmagnification
http://hyperphysics.phy-astr.gsu.edu/hbase/biology/celnuc.html
tp://www.windows2universe.org/earth/Life/cell_organelles.html
http://www.cellsalive.com/cells/cell_model.htm
https://www.boundless.com/physiology/textbooks/299/cellular-structure-andfunction-3/nucleus-and-ribosomes-44/structure-and-function-of-the-nucleus-andribosome-340-11449/