
The center is called the nucleus.
The nucleus is surrounded by a fluid
called the, cytoplasm.
The cell is
completely covered by a membrane called the Cell Membrane.
The cytoplasm combined with the nucleus, is
both referred to as the protoplasm.






One of the largest organelles within
the cytoplasm is the mitochondrion.
These organelles provide
cells with energy.
It is often referred to the
"power plant" of the cell, the mitochondria is the center of cell respiration.
Sugar molecules are combined with
oxygen to form the products, carbon dioxide and water.
The formation of these
products causes the release of energy.
However the energy is not made in the
mitochondria.
Chemical bonds within the sugar molecules
are broken down and chemical energy is converted into other forms of energy.
This energy enables muscle contraction, the synthesis of new molecules,
and the transport of certain molecules within the cell.

Ribosomes are one of the smallest of a
cells organelles, although tiny, ribsomes are the most numerous organelles within the cell.
Ribosomes organize and build proteins for the
body. Proteins are complex molecules that make up cell structure.
Cell growth and reproduction require that proteins be made
constantly.
The nucleus provides the
information for the type of protein needed.
Component building blocks, called
amino acids, are joined together by enzymes working with the ribosome.

The Endoplasmic Reticulum
is a series of canals that carry materials throughout the cytoplasm.
It is composed of parallel membranes
that may be rough or smooth.
They appear rough when they have many ribsomes attached to them.
Proteins made by the ribosome are
often transported by the endoplasmic reticulum.


Lysosomes are sac like structures that
break down large molecules.
Chemicals from the lysosomes can even
digest the cell that “houses them”, which causes them to be referred to as
“suicide sacs”.
They have the ability to break down
cellular proteins. This makes them
an important part of the human body’s defense mechanism.
The leukocyte engulfs invading bacteria.
Once inside the cytoplasm, the lysosomes destroy the bacterium and the white
blood cells.
The single cell can be sacrificed to
make sure that the harmful microbe does not spread and cause further damage and
the injured and worn out cells are also destroyed.
Special structures of plant cell 

All the structures discussed
above are both found in plant and animal cells
Plant cells have some structures that are
not found in animal cells, unlike animal cells, a large part of the cytoplasm
of plant cells is composed of fluid-filled space. These, fluid- filled space is called a vacuole.
Plastids are chemical factories and storehouses
for food and color pigments. Chloroplasts are plastids that contain the green pigments Chlorophyll, which is used in
photosynthesis.
Photosynthesis is the process by which plants combine carbon dioxide from the air
with water from the roots and, in the presence of light, make sugar and release
oxygen.

Created by Salome Hart