8/4/2019 Lecture 1-2011

1/89

MEDICAL BIOLOGY

8/4/2019 Lecture 1-2011

2/89

Lecture 1

Biology as a science of life.

Cell as an elementary unit of living matter.

8/4/2019 Lecture 1-2011

3/89

Plan:

1. Biology as a science, the subject-matter, main goalsand methods of studing.

2. The properties of a living matter and the levels ofbiological organization.

3. Cellular structure of a living matter.

4. Organization of hereditary material in pro- andeukaryotes.

5. Eukaryotic chromosomes, their chemical composion

and structural organization.

8/4/2019 Lecture 1-2011

4/89

Biology - is a scientific study of

natural laws of life

Bios life, logos study

The term of biology was used in 1802 by

G. R. Treviranus J. B. de Lamarck

(17761837) (1744 1829)

8/4/2019 Lecture 1-2011

5/89

Subject-matter

all forms of life in our planet and itsproperties

Main goals:1. To study the features and properties of a

living matter.

2. To know the essence of life.

8/4/2019 Lecture 1-2011

6/89

Main methods of biology

1. Descriptive method.

2. Comparative method.

3. Historical method.

4. Experimental method.5. Modeling method.

8/4/2019 Lecture 1-2011

7/89

Properties of a living matter

1. Specific organization, form, size and structure of living

matter.

2. Chemical composition.

3. Cellular structure (except viruses).4. Metabolism.

5. Selfregulation.

6. Growth and development.

7. Heredity and variability.

8. Irritability.

9. Reproduction.

10. Homeostasis.

8/4/2019 Lecture 1-2011

8/89

Levels of biological organization

8/4/2019 Lecture 1-2011

9/89

Classification of living organisms

Living organisms

Non-cellular Cellular

Viruses Prokaryotes Eukaryotes

Blue-greenalgae

Bacteria

Mushrooms

Plants

Animals

8/4/2019 Lecture 1-2011

10/89

CELL BIOLOGY

8/4/2019 Lecture 1-2011

11/89

Cell

elementary structural, functionaland genetic unit of living matter

8/4/2019 Lecture 1-2011

12/89

First image of cells byRobert Hook - 1665

(18.07.1635 - 3.03.1703)

Robert Hook

8/4/2019 Lecture 1-2011

13/89

CELL THEORY

1838 Matthias Schleiden

1839 Theodor Schwann

1858 - Rudolph Virchow

Matthias SchleidenTheodor Schwann Rudolph Virchow

8/4/2019 Lecture 1-2011

14/89

The modern states of cell theory

1. The basic unit of structure and function of

living organisms is cell.

2. All cells are basically alike in chemicalcomposition and metabolic activities.

3. All cells arise from the pre-existing by cell

division.

4. Multicellular organism consists of many

cells which are connect together and form

unique system.

8/4/2019 Lecture 1-2011

15/89

PROKARYOTES

8/4/2019 Lecture 1-2011

16/89

The main characters of prokaryotesA)They have no real nucleus, Nucleoid Region is the

cytoplasm region where DNA is located.

B) Bacterial Cell Wall = a rigid outer layer from murein

protein, that surrounds the cell membrane, protects

the cell, maintains shape.

C) Capsule is a sticky outer layer over cell wall.

D) Ribosomes 70S.

E)They have no membranous organelles.

F) Mesosomes are present.

8/4/2019 Lecture 1-2011

17/89

Scheme of prokaryotic cell

8/4/2019 Lecture 1-2011

18/89

Bacteria (electronic microscopy)

8/4/2019 Lecture 1-2011

19/89

8/4/2019 Lecture 1-2011

20/89

Eukaryotes

-have a nucleus;

-have a complex internal organization;

- have compartmentalized membrane bound

organelles

Animal cell

8/4/2019 Lecture 1-2011

21/89

Eukaryotic cells

Main components:

*Nucleus

*Plasma

membrane

*Cytoplasm

Animal cell

Plant cell

8/4/2019 Lecture 1-2011

22/89

Fluid mosaic modelof plasma membrane

1) Lipids (30%) phosphoglycerides, cholesterol2) Proteins (30%) peripheral, integral

3) Carbocchadrates (10%)

8/4/2019 Lecture 1-2011

23/89

FUCTIONS OF PLASMA MEMBRANE

1. Absorption of materials (endocytose);

2. Excretion of materials (exocytose);3.Transport of materials (diffusion, active

transport, facilitated transport);

4. Locomotion function;

5. Cell form;

8/4/2019 Lecture 1-2011

24/89

CELL

NUCLEUS

Structure:

1) Nuclear envelope

2) Nucleoplasm

3) Nucleolus4) Chromatin

Functions:

1. To keep the hereditary

material;

2. To control the metabolic

processes;

3. To synthesize the

ribosomes.

8/4/2019 Lecture 1-2011

25/89

CYTOPLASM

1. Cytosol.

2. Organelles.

3. Cell inclusions.

8/4/2019 Lecture 1-2011

26/89

8/4/2019 Lecture 1-2011

27/89

ORGANELLESOF EUKARYOTIC CELL

MEMBRANOUS NON-MEMBRANOUS

SINGLEMEMBRANOUS

DOUBLEMEMBRANOUS

1. MITOCHONDRIA2. PLASTIDS

1. ER

2. GOLGY BODY3. LYSOSOMES4. MICROBODIES5. VACUOLES

1. RIBOSOMES

2. MICROTUBULES(CENTRIOLES,FLAGELLA, CILIA,BASAL BODIES)

3. MICROFILAMENTS

8/4/2019 Lecture 1-2011

28/89

SINGLE MEMBRANOUSORGANELLES

8/4/2019 Lecture 1-2011

29/89

Endoplasmic

reticulum

-

ER - membrane system

Types:

Smooth ER (has ribosomes)

Rough ER (has no ribosomes)

8/4/2019 Lecture 1-2011

30/89

ER Functions

Smooth ER

1. Synthesis and transport of lipids andcarbohydrates.

Rough ER:

1. Synthesis and transport of proteins.

8/4/2019 Lecture 1-2011

31/89

Golgi body - a stack of flattened

membranous saca or cisternae

8/4/2019 Lecture 1-2011

32/89

Golgy body functions

1. Storage, packaging, sorting and modification

of proteins before exportation.

2. Lysosome formation.

3. Universal center of cell polymerization.

4. Transport of substances.

5. Synthesis of lipids, sugar, hormones andvitamins.

8/4/2019 Lecture 1-2011

33/89

Golgi body (electronic microscopy)

Dictyosome

Vacuole

Vesicles

Connection of ER and Golgi body

8/4/2019 Lecture 1-2011

34/89

Connection of ER and Golgi body

8/4/2019 Lecture 1-2011

35/89

Lysosome formation

8/4/2019 Lecture 1-2011

36/89

Lysosome functions

1. Intercellular digestion.

2. Autophagy.

3. Autolysis.

4. Exocytosis.

8/4/2019 Lecture 1-2011

37/89

DOUBLE MEMBRANOUSORGANELLES

Mi h d i

8/4/2019 Lecture 1-2011

38/89

Mitochondrion

1) Two membranes -

inner and outer;

2) Cristae;

3) Matrix;

4) Circular DNA;5) 70S ribosomes;

1) ATP synthesis

2) Autoreproduction

8/4/2019 Lecture 1-2011

39/89

Types of plastids

1. Chloroplasts (green colour)

- photosynthesis;

2. Leucoplasts (colourless)

- storage function;

3. Chromoplasts (red, orange, yellow colour)

- colour of flowers, fruits and vegetables.

Chloroplast structure

8/4/2019 Lecture 1-2011

40/89

1) Two membranes - inner and outer;

2) Thylakoid unit structure of chloroplast3) Granum group of thylakoids

4) Lamellae membranous extension connecting of grana5) Stroma chloroplast cytoplasm;

6) Circular DNA;

7) 70S ribosomes;

Chloroplast structure

Pl tid

8/4/2019 Lecture 1-2011

41/89

Plastids

8/4/2019 Lecture 1-2011

42/89

Non-membranous organelles

8/4/2019 Lecture 1-2011

43/89

Ribosome

Small subunitSmall subunit

Large subunitLarge subunit

RNARNA

ProteinsProteins

Function:

Proteinsynthesis

8/4/2019 Lecture 1-2011

44/89

Cytoskeleton

8/4/2019 Lecture 1-2011

45/89

Cytoskeleton (electronic microscopy)

Microfilaments - blue colour, microtubules green colour,intermediate microfilaments red colour.

Microfilaments = thinnest (actin)

Microtubules = thickest (tubulin)

8/4/2019 Lecture 1-2011

46/89

Functions of cytoskeleton

1. Cell form;

2. Movement of cell and its internalstructures.

3. Cell division.

8/4/2019 Lecture 1-2011

47/89

8/4/2019 Lecture 1-2011

48/89

The characters of a plant cell

Chloroplasts

Plasmodesma

Celluloseenvelope

Vacuole

1. No lysosomes.

2. No centrioles.

3. Presence ofcellulose

envelope.

4. Presence of big

central vacuole.

8/4/2019 Lecture 1-2011

49/89

Organization of hereditary material

in pro- and eukaryotes

8/4/2019 Lecture 1-2011

50/89

HEREDITY

property of living matter to providing

the characters in generations

8/4/2019 Lecture 1-2011

51/89

HEREDITARY MATERIAL

IN LIVING MATTER

NUCLEIC ACIDS:

DNA DIOXYRIBONUCLEIC ACID

RNA RIBONUCLEIC ACID

8/4/2019 Lecture 1-2011

52/89

DISCOVERY OF THE NUCLEIC ACIDS1869 - F. Miescher found thenucleic acids in human

white blood cells.

Phenomenon of Transformation

8/4/2019 Lecture 1-2011

53/89

Experiment of Griffiths (1928)

8/4/2019 Lecture 1-2011

54/89

Experiment of O.T. Avery, C.

Macleod and M. McCarty (1944)

They discovered transformingagent - DNA.

Experiment of Alfred Hershey and Marta Chase (1952)

8/4/2019 Lecture 1-2011

55/89

They were accepted thatDNA is the genetic

material

in all organisms.

Experiment of Alfred Hershey and Marta Chase (1952)

8/4/2019 Lecture 1-2011

56/89

CHEMICAL COMPOSITION

AND STRUCTURE

OF THE NUCLEIC ACIDS

Russian biochemist Phoebus Levene

8/4/2019 Lecture 1-2011

57/89

investigates the DNA Structure (1919)

Phoebus Levene

8/4/2019 Lecture 1-2011

58/89

Erwin Chargaff (1950) (Chargaffs rules)

He noted the nucleotide composition of DNA

8/4/2019 Lecture 1-2011

59/89

Primary structure of DNA

Phosphoricacid

Nucleotide

Phosphodiester bond

8/4/2019 Lecture 1-2011

60/89

Secondary structure of DNAHydrogen bond

Glycosidic bond

8/4/2019 Lecture 1-2011

61/89

Astbury, Wilkins and Franklin (1950-s)

They suggested helical configuration for DNA.

James Watson and Francis Crick (1953)

8/4/2019 Lecture 1-2011

62/89

James Watson and Francis Crick (1953)

They proposed the

double helical structure

for DNA molecule.

Tertiar str ct re of DNA

8/4/2019 Lecture 1-2011

63/89

Tertiary structure of DNA

(double helix)

Diameter

2 nm

Complete turn 3,4 nm

Distance between tonucleotides 0,34 nm

8/4/2019 Lecture 1-2011

64/89

Enzymes for DNA replication

8/4/2019 Lecture 1-2011

65/89

Enzymes for DNA replication

Topoisomerase helps to convert rings (supercoils) of

DNA from one topological form to another.

Helicase helps in unwinding the helix

Single-stranded DNA-binding (SSB) proteinstable the free single-stranded region.

RNA primase catalyzes the polymerization of RNA building

blocks (A, U, G, C) into the primer.

DNA polymerase synthesizes of DNA molecule.

DNA ligase catalyzes the linkage of Okazaki fragments

Semiconservative mechanism of DNA replication

8/4/2019 Lecture 1-2011

66/89

Semiconservative mechanism of DNA replication

Helicase

SSB-protein

RNA-

primer

Topoisomerase

RNA DNA

8/4/2019 Lecture 1-2011

67/89

RNA DNA

TYPES OF RNA MOLECULES:

8/4/2019 Lecture 1-2011

68/89

Messenger RNA (m-RNA)

Transfer RNA (t-RNA)

Ribosomal RNA (r-RNA)

magenta colour

HEREDITARY MATERIAL

8/4/2019 Lecture 1-2011

69/89

HEREDITARY MATERIAL

PROKARYOTES EUKARYOTES

Nucleoid Nucleus

Circle DNA Linear DNA

without with proteins

proteins (chromatin or chromosomes)

LEVELS OF ORGANIZATION OF

8/4/2019 Lecture 1-2011

70/89

LEVELS OF ORGANIZATION OF

HEREDITARY MATERIAL

* GENE LEVEL

* CHROMOSOMAL LEVEL

* GENOME LEVEL

8/4/2019 Lecture 1-2011

71/89

Gene level

8/4/2019 Lecture 1-2011

72/89

GENE

region of DNA molecule containing the

information about primary structure ofpolypeptide or about m-RNA and t-RNA

molecules.

G i

8/4/2019 Lecture 1-2011

73/89

Gene properties(Benzer, 1961) A gene is a segment of DNA. A gene has a unique sequence of nucleotide

base pairs.

A gene codes for a specific polypeptide, or r-RNA, or t-RNA, or polyprotein. A gene has a regulatory role. A gene can undergo crossing over and

mutation at times. A gene may have continuous or splitinformation.

Classification of genes

8/4/2019 Lecture 1-2011

74/89

Classification of genes

GENES

STRUCTURAL FUNCTIONAL

- promoter gene

- operator gene

- regulator geneeukaryotes exon and intron

OPERON

8/4/2019 Lecture 1-2011

75/89

OPERON(structural genetic unit of transcription of prokaryotes)

Gene

regulator

Gene

promoter

Gene

operatorG1 G2 G3 G4

Functional genes Structural genes

TRANSCRIPTON

8/4/2019 Lecture 1-2011

76/89

(structural genetic unit of transcription of eukaryotes)

Gene

regulator

Gene

promoter

Gene

operatorExon 1 Exon 2Intron 1 Intron 2

Structural genesFunctional genes

Space regions

8/4/2019 Lecture 1-2011

77/89

Chromosomal level

CHEMICAL COMPOSITION OF

8/4/2019 Lecture 1-2011

78/89

CHEMICAL COMPOSITION OF

CHROMATIN

1. DNA 40%

2. PROTEINS:

) HISTONES 40%;

) NON-HISTONES 20%;

3. RNA, enzymes, lipids, metal ions.

DNA is Condensed into Visible Chromosomes Only For

8/4/2019 Lecture 1-2011

79/89

DNA is Condensed into Visible Chromosomes Only For

Brief Periods in the Life of a Cell

95% of the time,

chromosomes are uncoiled

(chromatin).

Easily visible chromosomes are

apparent perhaps 5% of the

time in an actively growing cell

and less in a non-growing cell.

Levels of chromatin packing

8/4/2019 Lecture 1-2011

80/89

Levels of chromatin packing

The first level

8/4/2019 Lecture 1-2011

81/89

The first level

Nucleosome structure

DNA Histone H1

Protein globule

(8 histone molecules 2, 2, 3, 4)

nucleosome

The second level - Solenoid (fiber)

8/4/2019 Lecture 1-2011

82/89

( )

Metaphase chromosome

8/4/2019 Lecture 1-2011

83/89

(electronic microscopy)

8/4/2019 Lecture 1-2011

84/89

Structure of metaphase chromosome

Telomeres

Lower arms

ChromatidCentromere

Upper arms

8/4/2019 Lecture 1-2011

85/89

Morphological types of chromosomes

ACROCENTRIC

METACENTRIC SUBMETACENTRIC

TELOCENTRIC

8/4/2019 Lecture 1-2011

86/89

Genome level

Denver classification of human chromosomes

8/4/2019 Lecture 1-2011

87/89

Group A Group

Group EGroup D

Group

Group F Group G

Metaphase plate of human chromosomes

( l t i i )

8/4/2019 Lecture 1-2011

88/89

(electronic microscopy)

8/4/2019 Lecture 1-2011

89/89

THANK YOU

FOR YOUR ATTENTION