Cell
The cell is the smallest structural
and functional unit in living organisms. It is the basis of all vital
functions. It is the basic building unit. Some organisms may consist of only
one cell. Many organisms are made up of billions of cells. All cells are based
on a similar basic plan, Similar mechanisms are used to synthesize proteins and
convert energy to transport their essentials. Although the cells of the body
are similar, they have amazing properties that distinguish them from each other
easily. Each cell is remarkably independent. Each cell receives a supply of
nutrients and oxygen from the blood , And m Cell components and their vital
parts, with a specific task in which the cell's life is maintained.
Cell components
Despite the apparent variation of
cell types, cell components do not differ by cell type, and cell components are
as follows:
Plasma membrane: The thin
wall that line the cell from the outside. This membrane plays an important role
in isolating the cell from its surrounding environment.
The nucleus: serves as the
center of the cell's command, to grow the cell and mature and divide, it also
contains DNA, the genetic material of the cell, surrounds the nucleus of a
membrane called the nuclear casing, protects the DNA and separates the nucleus
from the rest of the cell.
Cytoplasm: It is found inside
the cells and consists of a gel-like liquid called the cellular cytoskeleton,
in addition to the structures surrounding the nucleus.
The endoplasmic network:
These cells help to process molecules that are created by the cell. These
molecules move to their specific targets, either inside or outside the cell.
Ribosomes are organelles that
process the cell's genetic instructions to create proteins.
Cytoskeleton: is the outer
frame of the cell, which performs a lot of functions.
Golgi device: Molecules are
processed by the endoplasmic network, to be transferred outside the cell.
Particles: These organelles,
the recycling center of the cell, digest bacteria that invade the cell, rid the
cell of toxic substances, and recycle the components of worn cells.
Mitochondria are complex
organelles that transform energy from food into a form that the cell can use.
Cell theory
Many biologists have agreed
on a common theory, called cell theory, which states:
All living organisms consist
of one or more cells.
All cells carry out life
activities, require energy and growth and have a specific size.
New cells of other living
cells are created, through the process of cellular division.
The cell has specialized
structures called organelles, which perform certain functions within the cell.
All cells have the same
chemical composition.
Total cell activity
determines the activity of the organism.
The most famous cell
scientists
Galileo's world: which had an
important role in the discovery of the cell, where he made a microscope, which
was the real nucleus, to detect the cell.
Robert Hooke: The name of the
cell, after being seen through a microscope, was launched in 1665
Robert Brown: The kernel and
some cell components.
Matthias Schleiden: The
theory of cell.
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