Cellular Level of Organization презентация

Cellular Level of Organization Lecture 2

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

Topic: 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.

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.

What studies Cytology (II) Cytology is closely related to

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 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

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.

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

Literature list

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

Features of the prokaryotic structure

Comparison of plant and animal cells:

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

Questions : Cell wall Microtubules Microfilament Cell center Ribosomes

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

Polytene chromosomes

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.