cell Cytology

1. A Tout into the Cell
By: mohammed AlbenSaad

2. LEARNING OBJECTIVES
 Cell
 Cytoplasm
 Cytoskeleton
 Cytosol
 Cell nucleus
 Cell Nucleolus
 Mitochondria

4. They contain membrane-bound organelles,
such as the nucleus, while prokaryotic cells
do not.
Differences in cellular structure:
eukaryotes include the presence of
mitochondria, chloroplasts,
cell wall and the structure
of chromosomal DNA.
Eukaryotic cells:

5. functions:
There are some types of cells are specialized
to perform specific functions for example:
nerve cells whose function is to transmit tiny
electrical pulses around an animal's nervous
system.
Although different types of cells generally
have different specialized functions, some
types of processes are common to all, or at
least most cell

6. Robert Hooke who discovered
the cells ..

7. Cytoplasm
 Cytoplasm is the substance
of a cell other than that of
the nucleus.
 Cytoplasm is made up of
three major elements;
cytosol, organelles, and
inclusions.
 Most cellular activities
happen in the cytoplasm.
The cytoplasm can be
thought of as the “factory
area” of the cell.

9. The structure of the
cytoplasm:
• contents of cells between the plasma
membrane and nucleus envelope.
It consists of a set of organelles suspended in
a liquid called essential cytosol, its consists
mostly of water containing mineral salts and
organic materials dissolved .

10. The function of the
cytoplasm:
 responsible for many cellular
processes like:-
 Movement of the different cellular
elements.
 Convert physical and chemical stimuli
into action potentials.
 Synthesis and secretion of steroids.

11. Cytoskeleton:
 It is a series of intercellular protein that
help the cell with shape.

12. The structure
 The main structures are:
 Microfilaments: are hollow tubes made of tubulin.
 Intermediate filaments
 Microtubules

13. The function of cytoskeleton
 Make the shape of the cell without
need to walls
 Organelle movement: help move
organelles from place to place in the
cell.

14. It is the fluid in which organelles of the cell
reside. This is often confused with cytoplasm,
which is the space between the nucleus and
the plasma membrane.
Cytosol

15. The structure of cytosol :
It is composed of water, salts and organic
molecules. Cytosol is composed of a mixture of
cytoskeleton filaments, organic and inorganic
molecules that are dissolved. The inner, more
fluid and granular potion of the cytoplasm is
known as the endoplasm.

16. The function of cytosol
It has enzymes that take molecules and
break them down, so that the individual
organelles can use them as they need to.
The cytosol also contains the cytoskeleton
which gives the cell its shape and can help
in the movement of the cell.

17. Cell nucleus:
It is a membrane-enclosed organelle
found in eukaryotic cells and It contains
most of the cell's genetic material.

18. The Structure of Cell nucleus:
1- Nuclear envelope :
known as nuclear membrane, consists
of two cellular membranes, an inner and
an outer membrane, arranged parallel to
one another.
2- Nuclear pores:
which provide aqueous channels
through the envelope, are composed of
multiple proteins.

19. 3- Nuclear lamina:
two networks of intermediate filaments provide the
nucleus with mechanical support.
It is composed mostly of lamin proteins
4- Chromosomes:
The cell nucleus contains the majority of the cell's
genetic material in the form of multiple linear DNA
molecules organized into structures called
chromosomes
Each human cell contains roughly two meters of
DNA. During most of the cell cycle these are
organized in a DNA-protein complex known as
chromatin

20. 5- Nucleolus:
It is a discrete densely stained structure
found in the nucleus. It is not surrounded
by a membrane, and is sometimes called
a suborganelle
The main roles of the nucleolus are to
synthesize rRNA and assemble ribosomes

21. The function of nucleus
The nucleus is a highly specialized
organelle that serves as the information
processing and administrative center of the
cell.
It coordinates the cell's activities, which
include growth, intermediary metabolism,
protein synthesis, and reproduction

22. Mitochondria
Mitochondria is a membrane bound cellular
structure and is found in most of the
eukaryotic cells.

23. Structure of mitochondria:
Outer membrane
It is smooth and is composed of equal amounts
of phospholipids and proteins.
It has a large number of special proteins known
as the porins.
Inner membrane
It is folded into a number of folds many times
and is known as the cristae.
This folding help to increase the surface ares
inside the organelle.

24.  Matrix
The matrix of the mitochondria is a complex
mixture of proteins and enzymes. These
enzymes are important for the synthesis of
ATP molecules, mitochondrial ribosomes,
tRNAs and mitochondrial DNA.

25. Functions of mitochondria:
 The most important function of the
mitochondria is to produce energy. The
energy known as ATP molecules.
 It is also help in building certain parts of
blood and hormones like testosterone and
estrogen.
 play important role in the process of
apoptosis or programmed cell death.