General structure of the cell presentation. Presentation on the topic: General structure of the cell

CONTENT
1 module
1. The structure of the atom. Rutherford's experiments.
2. Rutherford's model of the atom.
3. Radioactive transformation of atomic nuclei.
4. The composition of the atomic nucleus.
5. Fission of uranium nuclei.
6. Nuclear reactor.
7. Use of atomic energy.
2 module
1. and decay.
2. Law of conservation of mass and charge number.
3. Isotopes.
4. Thermo nuclear reaction.
STRUCTURE OF THE ATOM AND
ATOMIC NUCLEUS
2 - 4
5
7 - 9
6
13 - 15
10 -12
16
18
17
19
20

1896 Henri Becquerel (French) discovered the phenomenon of radioactivity.
Radioactivity - the ability of atoms to spontaneous radiation.
1899 Ernest Rutherford discovered that this radiation is non-uniform.
STRUCTURE OF THE ATOM

Rutherford's experiments
1. A grain of radium was placed in a thick-walled lead vessel.
Radium radiation was detected using a photographic plate.
2. A strong magnetic field was created around the cylinder.
The radiation was divided into three streams.
Consequently, radiation consists of streams of positive particles, negative and neutral.
The positive ones were called alpha particles (-particles);
Negative - beta particles (- particles);
Neutral - gamma particles (- particles) or - quanta or photons.
STRUCTURE OF THE ATOM
RADIOACTIVITY
N
S

Glass screen coated with a special substance
Radioactive substance that emits - particles.
Foil from the test
metal
1911 Rutherford conducts experiments to study the structure of the atom.
1. All particles hit the screen.
2. A strong deviation - of particles - the result of the action on them of a positively charged part of the atom, which has a rather large mass.
STRUCTURE OF THE ATOM
THE RUTHFORD EXPERIENCE

Particles core
According to Rutherford, the atom has a planetary structure.
In the center is a positively charged nucleus.
Electrons move around the nucleus.
The atom is neutral, because the charge of the nucleus is equal to the total charge of the electrons.
This structure of the atom explains the behavior - particles
STRUCTURE OF THE ATOM
RUTHERFORD'S ATOM MODEL

1903 Ernest Rutherford and Frederick Soddy discovered that when - decay occurs, the transformation of one chemical element in another.
Reaction - Decay:
+
Subsequently, it was found that the transformation occurs during - decay.
+ +
Core
- particle
- radiation
electron
- radiation
STRUCTURE OF THE ATOM
RADIOACTIVE TRANSFORMATION OF ATOMIC NUCLEI
OUTPUT
The nuclei of atoms are made up of smaller particles.

1919 Rutherford investigated the interaction of - particles with the nuclei of nitrogen atoms. At the same time, a particle flew out of the nucleus of the nitrogen atom, which he called a proton (first).
Later, using a cloud chamber, it was proved that this is indeed a positively charged elementary particle, which is the nucleus of the hydrogen atom.
In addition, the nucleus of the oxygen atom was formed.
+ +
is the nucleus of a hydrogen atom or proton.
Denoted - , has a mass of ≈ 1 amu.
and the charge is equal to the charge of the electron.
STRUCTURE OF THE ATOM
DISCOVERY OF THE PROTON

1920 Rutherford suggests the existence in the nucleus of a neutral particle with a mass equal to that of a proton.
In the 30s. when the nuclei of beryllium were bombarded with particles, a new radiation was discovered, which was called beryllium.
1932 James Chadwig proved that beryllium radiation is a stream of electrically neutral particles with a mass equal to that of a proton.
These particles are called neutrons.
STRUCTURE OF THE ATOM
DISCOVERY OF THE NEUTRON

N is the number of neutrons
1932 D.D. Ivanenko (Russian), V. Heisenberg (German) proposed a proton-neutron model of the structure of the nucleus:
The nucleus consists of protons and neutrons - nucleons.
EXAMPLE.
A = 56, Z = 26, N = 30
STRUCTURE OF THE ATOM
COMPOSITION OF THE NUCLEAR
The total number of nucleons in a nucleus is called
mass number and is denoted by A
The number of protons in a nucleus is called
charge number and denoted by Z
X
A
Z
A=Z+N
The number of protons for a given
element is constant.
The number of neutrons can be
more than the number of protons, it
may change (we get
isotopes of matter)

NUCLEAR POWER
1939 Otto Hahn and Fritz Strassmann (German) discover the fission of uranium nuclei.
Uranium nuclei are bombarded with neutrons.
If a neutron hits an unstable nucleus, then it is divided into two more stable nuclei, which fly apart with great speed.
At the same time, they emit 2-3 neutrons.
Fragments of the nucleus are slowed down and at the same time transfer their energy to the environment
fission of Uranium

NUCLEAR POWER
CHAIN REACTION

FACTORS AFFECTING LEAKAGE
CHAIN REACTION
1. THE MASS OF URANIUS.
2. THE PRESENCE OF A REFLECTING SHELL (beryllium).
3. PRESENCE OF IMPURITIES.
4. PRESENCE OF A NEUTRON MODELER - graphite, water, heavy water.
NUCLEAR POWER
CHAIN REACTION
The smallest mass of uranium at which
a chain reaction is possible
called critical mass

The nuclear reactor is part of
nuclear power plant
NUCLEAR POWER
NUCLEAR REACTOR

NUCLEAR POWER
NUCLEAR REACTOR
STRUCTURE OF A NUCLEAR REACTOR
1. Active zone. It contains:
nuclear fuel - enriched uranium-235;
neutron moderator (water).
2. Control rods are used to control the reaction.
3. Heat exchanger.
4. The core is surrounded by a beryllium reflector
and a protective shell of concrete

OPERATING PRINCIPLE
NUCLEAR REACTOR
1. A controlled nuclear reaction takes place in the active zone, as a result of which energy is released.
2. Energy is transferred to water.
3. Hot water enters the heat exchanger, where it heats the water, turning it into steam.
4. The water cools down and returns to the core.
This is the first closed loop.
5. Steam rotates the turbine (gives its energy to it) and condenses.
6. The pump pumps water to the heat exchanger.
This is the second closed loop.
NUCLEAR POWER
NUCLEAR REACTOR

1. NUCLEAR POWER PLANTS.
1942 Under the leadership of E. Fermi, the first nuclear reactor was built in the USA.
1946 The first nuclear reactor in the USSR was created under the leadership of IV Kurchatov.
1954 The world's first nuclear power plant was put into operation in the USSR.
2. Technique.
1. Spaceships.
2. Nuclear icebreakers.
3. Nuclear submarines.
3. Nuclear weapons.
STRUCTURE OF THE ATOM
USE OF NUCLEAR ENERGY

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Slides captions:

CELL STRUCTURE - BASIC ORGANOSES Biology teacher of the secondary school of the sanatorium "Druzhba" Holomeeva Anna Aleksandrovna

PURPOSE OF THE LESSON: Consider the structure of organelles and determine their functions

So where do we start, Mr Cyres? asked Pencroff the next morning. From the very beginning,” said Cyrus Smith. Jules Verne

Who discovered the cell Robert Hooke 1663 What is the name of the science of the cell Cytology

Organelles are structures that are constantly present in the cell and perform strictly defined functions.

Organelles Membrane nucleus ER Golgi complex Lysosomes mitochondria Non-membrane ribosomes cytoskeleton cell center

PLASMATIC MEMBRANE STRUCTURE Bilayer of lipids with proteins contained in it, which limits the cell

Cell membrane functions: separation of the contents of the cell and the external environment; regulation of metabolism between the cell and the environment; place of some biochemical reactions (including photosynthesis); association of cells into tissues. The most important property of the plasma membrane is semipermeability. Glucose, amino acids, fatty acids and ions slowly diffuse through it.

MEMBRANE STRUCTURE

Endocytosis

Exocytosis

Cytoplasm It is a watery substance - hyaloplasm (90% water), in which various organelles are located, as well as inclusions (lumps of glycogen, fat drops, starch crystals. Glycolysis, synthesis of fatty acids, nucleotides and other substances occurs in the hyaloplasm. It is a dynamic structure. Organelles move, and sometimes cyclosis is also noticeable - an active movement in which the entire protoplasm is involved.

CYTOPLASMA STRUCTURE Internal environment of the cell FUNCTIONS Ensures the activity of the cell as a single system

NUCLEUS STRUCTURE A closed reservoir surrounded by two layers of membranes pierced by nuclear pores. Inside is the nuclear sap, chromosomes (made of DNA and protein) and nucleoli (made of RNA and protein) FUNCTIONS Storage genetic information and RNA synthesis

Nucleus In size (10–20 µm), being the largest of the organelles. The most important function of the nucleus is the preservation of genetic information. It is covered with a nuclear membrane, which consists of two membranes: outer and inner, having the same structure as the plasma membrane. Between them is a narrow space filled with a semi-liquid substance. Through many pores in the nuclear envelope, the exchange of substances between the nucleus and the cytoplasm takes place (in particular, the release of mRNA into the cytoplasm). The outer membrane is often littered with ribosomes. Substances from the cytoplasm enter the karyoplasm (nuclear juice). Contains chromatin - a substance that carries DNA, and nucleoli - rounded structures inside the nucleus, in which the formation of ribosomes occurs. The totality of chromosomes contained in chromatin is called a chromosome set.

MITOCHONDRIA

MITOCHONDRIA STRUCTURE Oval bodies consisting of two layers of the membrane: outer (smooth) and inner (forms folds - cristae) FUNCTIONS ATP synthesis during respiration, capable of independent division

GOLGI COMPLEX

GOLGI COMPLEX STRUCTURE Complex of closed membrane reservoirs located near the nucleus FUNCTIONS Synthesis of fats and polysaccharides, transport of substances and their secretion, formation of lysosomes

The endoplasmic reticulum is a network of membranes that span the cytoplasm. connects organelles with each other, along it the transport of nutrients occurs. Smooth EPS has the form of tubules, the walls of which are made of a membrane. It synthesizes lipids and carbohydrates. There are many ribosomes on the membranes of the channels and cavities of the granular ER; this type of network is involved in protein synthesis.

LYSOSOME

LYSOSOMS STRUCTURE Closed membrane bodies containing enzymes that uncouple various substances of the cell FUNCTIONS Digestion of nutrients entering the cell, self-destruction of dying cells

Ribosomes are small (15–20 nm in diameter) organelles consisting of rRNA and polypeptides. The most important function is protein synthesis. Their number in the cell is very large: thousands and tens of thousands. Ribosomes can be associated with the endoplasmic reticulum or be in a free state. In the process of synthesis, many ribosomes usually simultaneously participate, united in chains, called polyribosomes (polysomes).

Microtubules Hollow cylindrical with a diameter of about 25 nm, the length can reach several micrometers. The walls of microtubules are made up of the protein tubulin. Centrioles Found in animal cells lower plants- small hollow cylinders tenths of a micrometer long, built from 27 microtubules. During cell division, they form a spindle of division. The basal bodies are identical in structure to the centrioles contained in the flagella and cilia. These organelles cause flagella to beat. Another function of microtubules is the transport of nutrients. Microtubules are fairly rigid structures that support the shape of the cell, forming a kind of cytoskeleton. Another form of organelles is also associated with support and movement - microfilaments - thin protein filaments with a diameter of 5–7 nm.

All organelles found in animal cells are present in plant cells (with the exception of centrioles). The cell walls of plants are made up of cellulose, which forms microfibrils. In the cells of treelike plants, the layers of cellulose are impregnated with lignin, which gives them additional rigidity. They serve as a support for plants, protect cells from rupture, determine the shape of the cell, play important role in the transport of water and nutrients from cell to cell. Neighboring cells are connected to each other by plasmodesmata passing through the small pores of the cell walls. A vacuole is a fluid-filled membrane sac. In animal cells, small vacuoles can be observed that perform phagocytic, digestive, contractile, and other functions. plant cells have one large central vacuole with cell sap. It is a concentrated solution of sugars, mineral salts, organic acids, pigments and other substances. Accumulate water, may contain coloring pigments, protective substances (for example, tannins), hydrolytic enzymes that cause cell autolysis, waste products, reserve nutrients.

Plastids: chloroplasts, chromoplasts, leucoplasts

CHLOROPLASTS

ANIMAL AND PLANT CELL

Plant cell Animal cell Similarity The presence of a plasma membrane. Cytoplasm Nuclei with nucleolus Chromosomes Endoplasmic reticulum Mitochondria Ribosomes Golgi complex Differences There is a central vacuole There are plastids No lysosomes The cell is covered with a cellulose cell wall on the outside No central vacuole No plastids There are lysosomes There is no cell wall, it is covered with glycocalex on the outside

CONCLUSION: The functions of organelles are complex and diverse. They play the same role for the cell as organs do for the whole organism.

Control summary of the material List the membrane organelles of the cell.

Cytoplasmic membrane, endoplasmic reticulum, Golgi complex, mitochondria, lysosomes, plastids

2. What chemicals form CM?

Proteins and lipids

What organelle is the energy station of the cell?

Mitochondria

What is the function of lysosomes?

Intracellular digestion and breakdown of substances

What is the function of the Golgi complex?

Synthesis of lipids and carbohydrates, secretion of proteins, carbohydrates and lipids

The value of ribosomes for the cell

protein synthesis

What organelles make up the cytoskeleton of a cell?

microtubules

What is inclusion?

Non-permanent structures where the supply of nutrients is located: fat, starch, protein

EPS value?

Rough ER - protein synthesis and transport Smooth ER - lipid synthesis and transport

What separates the nucleus from the cytoplasm?

bilayer nuclear membrane.

Name non-membrane organelles

Ribosomes, cell center, microtubules.

Homework: Know the structure of organelles and their functions Compose a crossword puzzle on the topic "Structure of the cell" Answer the questions in the paragraph in writing

List of sources used: Open Biology 2.6. LLC "Fizikon" 2000-2005.

Presentation on the topic "Structure of the cell" in biology in powerpoint format. The purpose of this presentation for schoolchildren is to consider the structure of organelles and determine their functions. Presentation author: biology teacher, Opaleva Elena Sergeevna.

Fragments from the presentation

Who opened the cage

Robert Hooke 1663

What is the name of the science of the cell

Cytology

Organelles are called structures constantly present in the cell that perform strictly

certain functions.

Membrane

golgi complex
Lysosomes
mitochondria

Non-membrane

ribosomes
cytoskeleton
cell center

plasma membrane

STRUCTURE

Bilayer of lipids with proteins in it, limiting the cell

FUNCTIONS

Barrier - protects the internal environment of the cell from the external
Nutrient - absorbs nutrients in the form of droplets (pinocytosis), particles (phagocytosis) or by diffusion

Output

The functions of organelles are complex and diverse. They play the same role for the cell as organs do for the whole organism.

Cell structure

Prepared by a biology teacher:

Zhambaeva A.M.

Cell- an elementary unit of the structure and life of all organisms, having its own metabolism, capable of independent existence, self-reproduction and development. The branch of biology that deals with the structure and function of cells is called cytology .

Who first saw the cage?

The first person to see cells was an English scientist Robert Hooke . In 1665 trying to figure out why corkwood swims so well, Hooke began to examine thin sections of cork with the help of a microscope improved by him. He found that the cork was divided into many tiny cells, which reminded him of the honeycombs in honey bee hives, and he called these cells cells (in English, cell means “cell, cell”).

Structural

cell components

Permanent

Fickle

Components

Perform specific

may appear or

vital

disappear in the process

cell activity

INCLUSIONS

ORGANOIDS

Organelles (organelles) are the permanent components of a cell that perform specific functions in it and ensure the implementation of the processes and properties necessary to maintain its vital activity.

Membrane

separates the contents of any cell from the external environment, providing it integrity ; regulates the exchange between cell and environment; intracellular membranes divide the cell into specialized closed compartments - compartments or organelles, in which certain environmental conditions are maintained.

Kernel Components

Karyoplasm

Karyolemma

Chromatin

nuclear juice,

contains

various proteins

organic and

inorganic

connections

round bodies,

educated

molecules

rRNA and proteins

place of assembly

Double nuclear

membrane

separates the nuclear

content and

first of all,

chromosomes from

cytoplasm

Despiralizo-

chromosomes

Chromosomes

Organelles of the nucleus of eukaryotes, each chromosome is formed by one DNA molecule and protein molecules
Carriers of genetic information

Cytoplasm

Cytoplasm- the internal environment of a living cell, limited by the plasma membrane.

Functions of the cytoplasm

Moves with it various substances, inclusions and organelles.
All metabolic processes take place in it.
The most important role of the cytoplasm is to unite all cellular structures (components) and ensure their chemical interaction.