cell cycle and cell division and cell biology .ppt

cell biology

1. Ministry of Health of the Republic of Uzbekistan
 Lecture 2
Compiled by: SHOKHISTA
 
Toshkent
– 2023
Topic:
Cellular foundations of life.  
  Cell
biology
 
Tashkent
Medical Academy
Department
of Histology and Medical Biology
Subject:
Medical Biology and Genetics
 

2.  Lecture
questions:
Hereditary
material of the cell.
Biology
of bacteria. Diseases caused by them.
Cell
theory, its significance. Evolution of the cell.
Ultrastructure
of eukaryotic cell, its significance in medicine.
Metabolism,
energy and information flows in the cell.
Cell
proliferation and its importance in medicine.
Topic: Cellular foundations of life.
 
Cell
biology

3. Non-cellular
life forms

4. Cellular forms of living things

5. The "chromosomes" of prokaryotes are
represented by a bare circular DNA
molecule. Prokaryotes contain only one
chromosome and are haploids. Genes are
arranged linearly and carry information
about the structure of 3–4.5 thousand
different proteins.

6. The chromosomes of eukaryotes, unlike the
chromosomes of prokaryotes, are built of
nucleoproteins, the main components of which are DNA
and two types of proteins - histone (basic) and non-
histone (acidic) proteins.
The length of DNA in a chromosome can reach
several centimeters.
The DNA of eukaryotes is structurally similar
to that of prokaryotes. The differences relate
to: the number of nucleotides in the genes, the
length of the DNA molecule, the order of
alternation of nucleotide sequences, the form of
folding (in eukaryotes - linear, in prokaryotes -
circular).

7. Eukaryotes are characterized by DNA redundancy.
The amount of DNA involved in encoding proteins
is only 2%. The rest of the DNA is represented by
the same sets of nucleotides, repeating
many
times - by repetitions. A distinction is made between repeatedly and moderately
repeating
sequences. They form constitutive heterochromatin (structural). It is
embedded
between unique sequences. Redundant genes are genes represented in
the
genome by 2 or more (up to 104) copies.

8. DNA in eukaryotes
•DNA
in eukaryotes is heterogeneous and can
be
divided into 3 classes:
•Frequently repeated sequences of nucleotides
- up to 106 times.
•Moderately repetitive - 10, 2-10, 3 times.
•Non-repetitive

9. 1.flagellum;
5. Plasmid;
Cell
wall; 6. Mesosome;
Cytoplasmic
membrane; 7. Cytoplasm;
Nucleoid
or Genophore; 8. Ribosomes;

11. Bacterial diseases
The name of
the disease
Exciter
Affected areas of the
body
Method of distribution
Tuberculosis
Mycobacterium tuberculosis is a
rod-shaped bacterium
Mostly lungs Droplet infection
Diphtheria
Coryne bacterium diphterine –
rod-shaped bacterium
Upper respiratory tractDroplet infection
Whooping
cough
Bordetella pertussis is a rod-
shaped bacterium
Upper respiratory tractDroplet infection
Gonorrhea
Neisseria gonorrhoeae –
coccus
Genitals
Contagious
transmission

12. Syphilis
Treponeta pallidum –
spirochete
Genitals
Contagious
transmission
Tetanus
Clostridium tetani is a rod-
shaped bacterium
Blood Wound infection
Cholera
Vibric cholerae – bacteria
in the form of a comma
Digestive tract
Fecal contamination
of water and
household items
Typhoid
Salmonella tuphi is a rod-
shaped bacterium
Digestive tract
Fecal contamination
of water and
household items

13. Signs Prokaryotes Eukaryotes
Nucleus
There is no decorated kernel. DNA
is located in the cytoplasm
They have a double-membrane
nucleus and nucleolus
Genetic material
Bacterial chromosome in the form
of circular DNA
A chromosome made up of DNA
and histone proteins
Cell wall There is, consists of murein and
pectin
There is no cellulose in animals,
chitin in fungi
Mesosoma
present absent
Membrane organelles
absent present
Ribosomes There are small
present
Cytoskeleton
absent present
Ways of penetration of substances into
the cell
It is transported through the cellularPhagocytosis or pinocytosis
Digestive vacuole
absent present
Mitosis or meiosis
absent present
Gametes
absent present
Flagella There are, but they differ in structure.
present
Size Average diameter 0.3 – 5.0 μm Diameter 40 μm or more

14. The German pathologist Virchow made a great contribution to the further
development of cell theory. Proving that the cell is formed from the original cell
In 1958, Virchow's book "Cellular Pathology" was published. In this book,
Virchow pointed out that pathological processes are associated with changes in the
structure of cells. This information formed the basis for the emergence of the service of
pathological anatomy and sectoral work, which are of great importance in theoretical
and clinical medicine.
The cell theory was created in 1839 by Schwann and Schleiden
Cell theory and its significance

16. Structure and function of eukaryotic cells.

17. Structure and function of eukaryotic cells

23. Through the plasmolemma, substances are transported into the cell.
•Transport can be passive and active.
•1. Passive transport occurs without energy consumption, along the concentration gradient.
This can be: diffusion of gases, osmotic movement of water, facilitated diffusion of
substances (amino acids, sugars, fatty acids) through carrier proteins.
•2. Active transport goes against the concentration gradient, with the expenditure of energy.
It requires the presence of special ion channels, enzymes and ATP. This is how the sodium-
potassium pump works. The concentration of potassium in the cell is higher than in the
pericellular space, and, nevertheless, potassium ions enter the cell, and sodium ions are
excreted outside.
•The charge on the membrane ensures the transmission of nerve impulses, the absorption of
nutrients by the villi of the intestine, adsorption in the renal tubules.
•The Mg2+/Ca2+ pump provides muscle contractions.
•Large-molecule compounds of proteins, nucleic acids, polysaccharides penetrate into the cell
by endocytosis. There are 2 types of endocytosis: phagocytosis and pinocytosis. Phagocytosis
is the capture of solid particles by the membrane. At the same time, a digestive vacuole is
formed inside the cell with the participation of lysosomes. Pinocytosis is the flow of fluids
into the cell.
•The release of substances enclosed in the membrane from the cell is called exocytosis.
•The substances entering the cell can be used:
•1) for the synthesis of substances necessary for the cell itself (anabolic system);
•2) as a source of energy (catabolic system).
•

29. Endoplasmic reticulum

33. Lysosomes,
functions and types
•Contains
a set of hydrolytic
enzymes;

•Primary lysosome (save
granules);
•Secondary lysosome
(phagosome + primary
lysosome) – heterophago
soma;
•They also participate in the
removal of whole cells and
intercellular substances;
•

36. The
structure of the plastid

38. The structure of the cell center

39. The anabolic system of the cell and its organelles: endoplasmic
reticulum, Golgi complex, ribosomes
Anabolic (assimilation, plastic metabolism) and catabolic
(dissimilation, energy metabolism) systems of the cell are
inextricably linked, since all the processes of cell life are
inconceivable without ATP energy, which, in turn, cannot be
formed without enzyme systems built as a result of anabolic
reactions. Also, the flows of matter and energy are inextricably
linked with each other, since heterotrophic cells are able to use
only the energy contained in complex chemical compounds. The
anabolic system of the cell includes: ribosomes, endoplasmic
reticulum, Golgi complex.
•

40. Catabolic system and its organelles: lysosomes,
peroxisomes, glyoxysomes, mitochondria
The catabolic system of the cell includes: lysosomes, peroxisomes, glyoxysomes, mitochondria.
•Peroxisomes are cellular organelles in which fatty acids are oxidized,
bile acids, cholesterol, and ester-containing lipids are synthesized,
which are involved in the construction of the myelin sheath of nerve
fibers. They are found in all eukaryotic cells. Their functions vary
greatly in different types of cells. This is one of the main centers for
the utilization of oxygen in the cell. Contain enzymes: oxidases, urat
oxidases and catalases. Catalase oxidizes phenols, formic acid,
formaldehyde and alcohols. This type of oxidative reaction is
especially important in liver and kidney cells, where peroxisomes
neutralize toxic substances that enter the bloodstream.
Glyoxysomes are plant cell organelles that contain the enzymes
needed to convert fats into carbohydrates.
•

43. The nucleus (nucleus, karion) is a permanent structural component of all eukaryotic cells. The shell of the
interphase nucleus consists of 2 elementary membranes (outer and inner), the space between which is called
perinuclear. Membranes have pores through which there is an exchange of substances between the nucleus
and the cytoplasm. The outer nuclear membrane passes into the walls of the channels of the granular
endoplasmic reticulum, on which the ribosomes are located.
•Nucleoplasm is a homogeneous mass that fills the space between
the structures of the nucleus. It contains proteins, nucleotides, ATP
and various types of RNA, as well as chromatin and nucleoli.
•Chromatin is a complex of DNA and histone proteins
(deoxyribonucleoprotein) in a ratio of 1: 1.3. It is detected in the
interphase nucleus. In the process of mitosis, spiralized chromatin
forms chromosomes.
•Nucleolus - consists of proteins (80%), RNA (up to 15%), DNA (up to
12%).
•It is formed in the nucleolar organizer on the chromosome. Provides
the synthesis of r-RNA and the formation of ribosome subunits.
•Functions of the nucleus: storage and transmission of genetic
information, regulation of cell vital processes.
•

48. TYPES OF SEXUAL REPRODUCTION
Two major types of sexual reproduction are
 
syngamy 
and 
conjugation.
 
Syngamy 
refers to the fusion of haploid sex cells resulting in the formation of a diploid zygote. Thus, in essence, syngamy
refers to
 
fertilization. It is the most common type of reproduction in multicellular sexual populations, including humans.
Conjugation 
is different from syngamy in such a way that two organisms come together in a 
temporary 
fusion (e.g. by
a
 
cytoplasmic bridge) to exchange micronuclear material. This can be observed among single-celled organisms, such as
bacteria, protozoans, and single-celled fungi. While syngamy is a permanent fusion of the two cells, conjugation is a
temporary fusion of two cells.

51. Cell
multiplication
Somatic
Sexual
(amitosis,
mitosis) (meiosis)
Mitotic
cycle - mitosis

52. Cell division
•
By the rate of
division
Rapidly dividing - intestinal epithelial cells
Division from medium speed - liver cells
Non-dividing – nerve cells
Regulatory factors of
cell division
Out-of-cell (exogen)
intracellular (endogen)
R
1
R2
G
2
G
1
S Mitosis
Autosynthetic
interphase
Heterosynthetic
interphase
Cell death
Growth
differentiation
specialization
Physiological
process

56. KEYLONS are substances from the category of low
molecular weight glycoproteins that regulate the
process of cell proliferation. They are formed in
differentiated cells and suppress the division of stem
cells, thereby regulating the quantitative composition
of the cell population. Keylons have tissue specificity,
but at the same time they lack species specificity.
Currently, G1- and G2-keylons have been described.
The former block the transition from the G1 phase to
the DNA synthesis phase, and the latter cause a delay
in cells at the postsynthetic stage (G2).

57. Reproduction of germ cells - meiosis