Research methods in cytology презентация

Topics:
RESEARCH METHODS IN CYTOLOGY
Cell. Membrane organelles
Cell. REMEMBRANCE ORGANELLES
Nucleus, chromosome

Topic: RESEARCH METHODS
IN CYTOLOGY

RESEARCH METHODS
IN CYTOLOGY
QUESTIONS
What studies Cytology.
The idea that organisms are made up of cells.
Research methods used in Cytology.
Cell fractionation.
Autoradiography.
Determination of the duration of some stages of the cell cycle by radio.

RESEARCH METHODS
IN CYTOLOGY
What studies Cytology (I)
Cytology - the science of the cell.
From among other biological Sciences, it stood out almost 100 years ago.
For the first time generalized information about the structure of cells were collected in the book Zh.-B. Karnua «Сell Biology", published in 1884.
Modern Cytology studies:
structure of cells, their functioning as elementary living systems;
the functions of individual cell components;
the process of reproduction of cells and their reparations;
adaptation to environmental conditions and many other processes that allow to judge the properties and functions common to all cells.
Cytology also considers the features of the structure of specialized cells.

RESEARCH METHODS
IN CYTOLOGY
What studies Cytology (II)
Cytology is closely related to
Biochemistry
Biophysics
Molecular biology
Genetics
The discipline "Cytology" refers to the fundamental sections of biology, because it explores and describes the only unit of all life on Earth – the cell.

Cell theory
In the XVII century. Robert Hooke, a physicist and biologist, characterized by great ingenuity, created a microscope. He called small units cells.
in 1839, Matthias Schleiden (Germany) and Theodor Schwann (Germany) independently formulated the cell theory

The main positions of the cell theory (I)
The cell is the basis of structural and functional organization of plants and animals;
Plant and animal cells are similar in structure and develop similarly (by dividing the original cell);
Cells in all organisms have a membrane structure;
The nucleus of a cell represents its main regulatory organoid;
Cellular structure of living organisms is the evidence of the unity of their origin

The main positions of the cell theory (II)
Additions were made to the cell theory in the period of 1855-1859
Rudolf Virchow (Germany):
Cells arise only from cells through reproduction. This point of the cell theory excludes the possibility of cell formation from the non-cellular material;
The cell is a unit of pathology..

RESEARCH METHODS
IN CYTOLOGY
Research methods in Cytology
Ordinary light microscopy, which has not lost its role.
Polarizing microscopy.
Ultraviolet microscopy.
Fluorescence microscopy.
Phase-contrast microscopy.
Electron microscopy

RESEARCH METHODS
IN CYTOLOGY
Modern research methods
The most useful in modern times were:
1) Electron microscopy;
2) Fractionation of cells by which biochemists can identify a relatively pure fraction of cells contain certain organelles, and to study, thus separate they are interested in metabolic reactions;
3) radioautography, which made it possible to directly study the individual metabolic reactions occurring in organelles.

RESEARCH METHODS
IN CYTOLOGY
Fractionation method
The method allows:
to separate different organelles of the cell in a relatively pure form;
determine the chemical composition of organelles and enzymes contained in them;
on the basis of the data obtained to draw conclusions about the functions of organelles in the cell.
to determine the chemical composition and enzymatic activity of the selected organelles.

The stages of fractionation of the cell
Cell fractionation by centrifugation
Repeated centrifugation at progressively higher speeds will fractionate homogenates of cells into their components. In general, the smaller the subcellular component, the greater is the centrifugal force required to sediment it.
Typical values for the various centrifugation steps referred to in the figure are:

RESEARCH METHODS
IN CYTOLOGY
Literature list
Molecular Biology of the Cell. 4th edition.
Alberts B, Johnson A, Lewis J, et al. New York: Garland Science; 2002

Topic: Cell. Membrane organelles

Questions:
General outline of the cell structure
Features of the structure of prokaryotic cells
Comparison of plant and animal cells
Characteristic of membranes
Lysosomes
Golgi apparatus
Endoplasmic reticulum
Mitochondria
Plastids
Vacuole
Metabolic cycle in a cell

General outline of the cell structure

SHELL
(cell wall + cytoplasmic membrane in plants
or cytoplasmic membrane in animals)
PROTOPLASM
(the contents of the cell)
KARYOPLASM
(nucleus substance)
CYTOPLASM
(all other contents of the cell)
CYTOSOL
(soluble part of cytoplasm)
ORGANOIDS
(structurally and functionally isolated parts of the cytoplasm)
SPARE NUTRIENTS
(organic and inorganic)
Cell
MEMBRANOUS
Lysosomes, Golgi apparatus, endoplasmic reticulum, mitochondria, plastids
Non-MEMBRANE
Cell center, microtubules, microfilaments, cilia, flagella

Features of the prokaryotic structure
Capsule (pectin mucosa)
Cell wall
Cytoplasmic membrane (CPM)
Nucleoid
Plasmids
Mesosome
Ribosomes (size -
Fimbriae (pili)
Flagellum
Cytoplasm
(ring DNA, membrane of the cytoplasm is not separated)
(contains murein, not cellulose)
Photosynthetic membrane
(invagination inside the CPM cells, a functional analog of the chloroplast)
(invagination inside the CPM cells, a functional analog of the mitochondrial)
(flagellin's protein thread moves due to the rotation of the inner ring, not the contraction of the thread itself)
(70 S, but not 80 S)
(contain additional genetic material)
(attachment to substrate and absorption of nutrients)

Comparison of plant and animal cells:
TYPE OF NUTRITION
AUTOTROPHIC
(synthesis of organic substances from inorganic)
HETEROTROPHIC
(synthesis of organic substances only from organic
Plant cell
Animal cell
Cell wall
PLASTIDS
(the organelles responsible for autotrophic type of nutrition)
VACUOLE
in lower animals performs a digestive function
ATP synthesis
mitochondria, chloroplasts
mitochondria
CELLULAR CENTRE
only in lower animals
SPARE CARBOHYDRATES
starch
glycogen

Biological membrane
Protein molecules (80-20%) immersed in lipid bilayer (20-80%)
GLYCOCALYX
PERIPHERAL PROTEINS
INTEGRAL PROTEINS
recognition of external signals adhesion of cells in the tissue
immune response
form a hydrophilic channel - pore
transported through the membrane of certain substances (are carriers)

Transport of substances through the plasma membrane
ACTIVE TRANSPORT
PASSIVE TRANSPORT
(DIFFUSION)
ENDOCYTOSIS
EXOCYTOSIS
PHAGOCYTOSIS
PINOCYTOSIS
TRANSFER
PENETRATION
Ordinary DIFFUSION
Facilitated DIFFUSION
Binding of the dissolved substance
Carrier inversion
Release of dissolved substance
PERMEASE
As well as the active transport is carried out by using protein vectors

Topic: Membrane organelles

Hypotheses of increasing the number of mitochondria in a cell:
Mitochondria are formed from precursors (promitochondria)
Mitochondria are formed from other membrane organelles of the cell
The increase in the number of mitochondria in the cell occurs as a result of the division of the mitochondria

Topic: CELL.
REMEMBRANCE ORGANELLES

RESEARCH METHODS
IN CYTOLOGY
Questions :
Cell wall
Microtubules
Microfilament
Cell center
Ribosomes

Cell wall in bacteria

Topic: Nucleus. CHROMOSOME

Questions:
Structure and functions of the nuclear apparatus of the cell
Definition of chromosome
Structure and function of chromosomes
Types of chromosomes
Chromosomes of "tube brushes" type
Polytene chromosomes
B-chromosomes

Chromosome
The chromosome is a permanent component of the nucleus, characterized by a special structure, personality, function and ability to reproduce itself, which ensures the continuity and transmission of hereditary information from one generation of living organisms to another.
Its name was due to the ability to intensely colored basic dyes. The term "chromosome" was proposed in 1888 by Valldaura.

Functions of chromosomes
1. Information - contains DNA, which contains qualitatively different genes that make up the genome of the cell.
2. Transcription – the reading of the information contained therein in the course of gene expression.
3. Structural and organizational - provides extremely accurate reproduction of chromosomes during replication and identity of child chromosomes diverging to the poles.
4. Segregation - provides distribution of chromosomes along the poles in different spores or gametes in meiosis.
5. Recombination - provides a significant part of the combinative variability - recombination of linked genes.

Karyotype
Karyotype - chromosomal complex species with its own characteristics:
the number and size of chromosomes;
their morphology;
the presence of under a light microscope parts of the structure, constrictions, satellites,
shoulder ratio, alternation of EU-and heterochromatin.
The most important property of the karyotype is the presence of pairs of homologous chromosomes.

Polytene chromosomes
It was discovered in 1881 by Balbiani
Characteristics:
in terms of volume, about 1000 times more somatic due to 9 – 10 consecutive replication;
the cell cycle in cells of this type consists of only 2 phases: synthesis of DNA and synthetic period;
polytene chromosomes are not able to enter into mitotic divisions.
VALUE: due to polyteny, the body mass increases much faster than due to mitotic divisions of diploid cells.

CHROMOSOME TYPE "OF TUBE BRUSHES»
Were opened In 1878 by W. Fleming
Can be found in meiosis at the stage of prophase I, in diplotene
Formed in the course of extremely long meiotic division.
Chromosomes of type "Tube brushes" – diplotene bivalent, consisting of two chromosomes, which intersect in the points a chiasm.