Lector : professor Fedonyuk L.Ya .

1. Introduction to the Medical Biology. Structural and functional organization of cells and viruses. Lector: professor FedonyukL.Ya.

2. Questions for discussion: • General and medical Biology as the sciences. • Levels of living organization. • Characteristics of living things. • Thecelltheoryinitsmodernform. • Cellular level of life organization: -prokaryotic and eukaryotic cells -the differences between plant and animal cells. • Themaincomponentsofeukaryoticcell. • Cell membrane (plasmalemma) • Cytoplasm (organelles and inclusions) • Nucleus

3. Biology literally means "the study of life". Biology is such a broad field, covering the minute workings of chemical machines inside our cells, to broad scale concepts of ecosystems and global climate change. Biologists study intimate details of the human brain, the composition of our genes, and even the functioning of our reproductive system.

4. Biologists recently all but completed the deciphering of the human genome, the sequence of deoxyribonucleic acid (DNA) bases that may determine much of our innate capabilities and predispositions to certain forms of behavior and illnesses. DNA sequences have played major roles in criminal cases (OJ. Simpson, as well as the reversal of death penalties for many wrongfully convicted individuals), as well as the impeachment of President Clinton (the stain at least did not lie). We are bombarded with headlines about possible health risks from favorite foods (Chinese, Mexican, hamburgers, etc.) as well as the potential benefits of eating other foods such as cooked tomatoes. Infomercials tout the benefits of metabolism-adjusting drugs for weight loss.

5. Modernbiology isbasedonseveralgreatideas, ortheories: • TheCellTheory • TheTheoryofEvolution • GeneTheory • Homeostasis

6. Levels of living organization • Biosphere • Ecosystem • Community • Populations • Individuals • Organ System • Organ • Tissue • Cell • Organelle • Molecule

7. LEVELS OF LIVING ORGANIZATION MICROSYSTEMS molecular (size - ≤ 1 nm) subcellular (size - 1 nm – 100 nm) cellular (size – 0,2 – 20 mkm)

8. MESOSYSTEMSTissue(size – 10-100 mkm)Organ(size - 0,1 mm and more)Organism(size – 1 smand more)

9. MACROSYSTEM • Community • Ecosystem • Biosphere

10. Levels of living organization • Biosphere • Ecosystem • Community • Populations • Individuals • Organ System • Organ • Tissue • Cell • Organelle • Molecule

11. Levels of living organization • Biosphere • Ecosystem • Community • Populations • Individuals • Organ System • Organ • Tissue • Cell • Organelle • Molecule

12. Population level

13. Community level (I) • A community is the set of all populations that inhabit a certain area. Communities can have different sizes and boundaries. These are often identified with some difficulty. • An ecosystem is a higher level of organization the community plus its physical environment. Ecosystems include both the biological and physical components affecting the community/ecosystem. We can study ecosystems from a structural view of population distribution or from a functional view of energy flow and other processes.

14. Community level (II) • There are two basic categories of communities: terrestrial (land) and aquatic (water). These two basic types of community contain eight smaller units known as biomes. A biome is a large-scale category containing many communities of a similar nature, whose distribution is largely controlled by climate • Terrestrial Biomes: tundra, grassland, desert, taiga, temperate forest, tropical forest. • Aquatic Biomes: marine, freshwater

15. Biosphere • Thesumofalllivingthingstakeninconjunctionwiththeirenvironment. Inessence, wherelifeoccurs, fromtheupperreachesoftheatmospheretothetopfewmetersofsoil, tothebottomsoftheoceans. Wedividetheearthintoatmosphere (air), lithosphere (earth), hydrosphere (water), andbiosphere (life)

16. Levels of the living organization

17. MAIN METHODS OF SCIENTIFIC INVESTIGATION • light microscopy; • lectron microscopy; • Stepsinthescientificmethod • commonlyinclude: • Observation: defining the problem you wish to explain. • Hypothesis: one or more falsifiable explanations for the observation. • Experimentation: Controlled attempts to test one or more hypotheses. • Conclusion: was the hypothesis supported or not? After this step the hypothesis is either modified or rejected, which causes a repeat of the steps above.

20. ROBERT HOOKE microscope

21. ANTON VAN LEEUWENHOEK microscope

23. Characteristics of living things • useenergy – have a metabolism- thebuildingupandbreakingdownofchemicals • growanddevelopbecomelargerandmorecomplexrespondtotheirsurrounding • reproduce- produceoffspringthataresimilartotheparents • havethechemicalsoflife, carbohydrates, proteins, lipidsandnucleicacids (geneticmaterial)   • havecells The fundamental characteristics of living things: • reproduction(self-reproduction), which is the process that gives rise to offspring; • genes(self-renewal) are the units of inheritance, passed prom parent to offspring, that control many daily functions. • Finally, populations of living organisms adjust to environment variations through evolution, a change in the traits of a species over time (self-regulation).

24. CELLULAR LEVEL OF LIVING ORGANIZATION

25. no cellular living forms - viruses

26. CLASSIFICATION OF CELLS cellular living forms - cells • According to the cell’s nucleus presence: • Prokariotic • Eukaroitic 2.According to the nature: • Plant cells • Animal cells 3.According to the type: • Somatic cells • Sex cells

27. Kingdoms of living organisms

28. Monera Monera, the most primitive kingdom, contain living organisms remarkably similar to ancient fossils. Organisms in this group lack membrane-bound organelles associated with higher forms of life. Such organisms are known as prokaryotes. Bacteria (technically the Eubacteria) and blue-green bacteria (sometimes called blue-green algae, or cyanobacteria) are the major forms of life in this kingdom. The most primitive group, the archaebacteria, are today restricted to marginal habitats such as hot springs or areas of low oxygen concentration.

29. Protista Protista were the first of the eukaryotic kingdoms, these organisms and all others have membrane-bound organelles, which allow for compartmentalization and dedication of specific areas for specific functions. The chief importance of Protista is their role as a stem group for the remaining Kingdoms: Plants, Animals, and Fungi. Major groups within the Protista include the algae, euglenoids, ciliates, protozoa, and flagellates.

30. Fungi Fungi are almost entirely multicellular (with yeast, Saccharomyces cerviseae, being a prominent unicellular fungus), heterotrophic (deriving their energy from another organism, whether alive or dead), and usually having some cells with two nuclei (multinucleate, as opposed to the more common one, or uninucleate) per cell. Ecologically this kingdom is important (along with certain bacteria) as decomposers and recyclers of nutrients. Economically, the Fungi provide us with food (mushrooms; Bleu cheese/Roquefort cheese; baking and brewing), antibiotics (the first of the wonder drugs, Penicillin, was isolated from a fungus Penicillium), and crop parasites (doing several billion dollars per year of damage).

31. Plantae Plantae include multicelled organisms that are all autotrophic (capable of making their own food by the process of photosynthesis, the conversion of sunlight energy into chemical energy). Ecologically, this kingdom is generally (along with photosynthetic organisms in Monera and Protista) termed the producers, and rest at the base of all food webs. A food web is an ecological concept to trace energy flow through an ecosystem. Economically, this kingdom is unparalleled, with agriculture providing billions of dollars to the economy (as well as the foundation of "civilization"). Food, building materials, paper, drugs (both legal and illegal), and roses, are plants or plant-derived products.

32. Animalia Animalia consists entirely of multicelluar heterotrophs that are all capable (at some point during their life history) of mobility. Ecologically, this kingdom occupies the level of consumers, which can be subdivided into herbivore (eaters of plants) and carnivores (eaters of other animals). Humans, along with some other organisms, are omnivores (capable of functioning as herbivores or carnivores). Economically, animals provide meat, hides, beasts of burden, pleasure (pets), transportation, and scents (as used in some perfumes).

33. ROBERT HOOKE- first to look at cellslooked at a thin section of cork ANTON VAN LEEUWENHOEK – made his own lenses made first compound microscope drew pictures that we can still identify today Schleiden –concluded all plants are made of cells Schwann – concluded all living things are made up of cells Cell theory • ROBERT HOOKE- first (1665) looked at a slice of dried cork. He noticed that plant tissues are made up of small, regulatory cavities surrounded by walls. Hooke called this “cell”. • ANTON VAN LEEUWENHOEK – made his own lenses made first compound microscope drew pictures that we can still identify today • SCHLEIDEN – concluded all plants are made of cells • TEODOR SCHWANN – concluded all living things are made up of cells. The first strong statement that “all living organisms consist of cell” was made by him in 1839. • In 1858 Rudolf Virchov suggested that “all cells come from pre-existing cells”.

34. MAIN PRINCIPLES OF THE CELL THEORY: • 1. All organisms are composed of one or more cells, within which the life processes of metabolism and hereditary occur. • 2. Cells are the smallest living things, the basic unit of organization of all organisms. • 3. Cells arise only by division of a previously existing cell.

35. The cell is the basic unit of life. Microorganisms such as bacteria, yeast, and amoebae exist as single cells. By contrast, the adult human is made up of about 30 trillion cells (1 trillion = 1012) which are mostly organized into collectives called tissues. Properties - biomembrane enclosed - four biomolecules: proteins, polysacharides, nucleic acids, lipids - metabolism and energy transformation

36. Lots of shapes and sizes

37. What are the differences between prokaryotic and eukaryotic cells? • Kindoms Kindoms 1. Monera (Fubacteria) 1. Protista 2. Archaea (Archaebacteria) 2. Fungi 3. Plantae 4. Animalia Characteristics Characteristics 1. Lack a nuclear membrane 1. Have a nuclear membrane 2. Have no membrane bound organels 2. Have membrane bound organels Current evidence indicates that eukaryotic evolved from prokaryotic between 1 and 1,5 billion years ago

39. Eukaryotic cell hasthree main components: 1) nucleus; 2) cytoplasm; 3) cell membrane.

40. CELL MEMBRANE (plasma membrane) Separates the living cell from its nonliving surroundings. It is 7,5-11 nm (that is, 7,5-11 billionths of a meter) thick. This membrane envelops the cell, and nothing can enter or leave the cell without crossing it.

41. Plasma membrane Composed of: • outer leaflet – GLYCOCALIX – facing the extracellular environment • lipid bilayer with associated proteins– BIOLOGICAL MEMBRANE) • inner leaflet – CORTICAL LAYER – facing the cytoplasm

42. Biological membrane Organization: The widely accepted fluid mosaic model describes biologic membranes as “protein icebergs in a lipid sea.” It is omposed of lipid bilayer and associated proteins. Lipids are present in cell membranes as phospholipids,sphingolipids, and cholesterol. Each phospholipid molecule has a polar (hydrophilic) phosphate-containing head group and a nonpolar (hydrophobic) pair of fatty-acid tails. Membrane phospholipids are arranged in a bilayer with their tails directed toward one another at the center of the membrane. In electron micrographs of osmium-stained tissue, a single membrane, or unit membrane, has 2 dark outer lines with a lighter layer between them. 1 – heads; 2 – tails; 3 – integral proteins.

43. Fluid-mosaic structure of the cell membrane

44. Proteinmay comprise over 50 % of membrane weight. Most membrane proteins are globular and belong to one of the following 2 groups: • Integral membrane proteins are tightly lodged in the lipid bilayer; detergents are required to extract them. They are folded, with their hydrophilic amino acids in contact with the phosphate groups of the membrane phospholipids and their hydrophobic amino acids in contact with the fatty-acid tails. Some protrude from only one membrane surface, while others, called transmembrane proteins, penetrate the entire membrane and protrude from both sides. • b. Peripheral membrane proteins are more loosely associated with the inner or outer membrane surface; some are globular, some filamentous.

45. Cell membrane proteins

46. GLYCOCALYX Carbohydrates occur on plasma membranes mainly as oligosaccharide moieties of membrane glycoproteins and glycolipids. Membrane oligosaccharides have a characteristic branching structure and project from the cell’s outer surface, forming a superficial coat called the glycocalyx that participates in cell adhesion and recognition.

47. Glycocalyx • is a sugarcoatcommonlyassociatedwiththeextracytoplasmicaspectsoftheouterleafletofplasmamembrane (inanimalcells). Functions • aidingincellularattachmenttoextracellularmatrixcomponents • bindingofcellularandenzymestothecell

48. CORTICAL LAYER Is located inside the cytoplasm of the cell. It is composed by microtubules and microfilaments, which formed the cytoskeleton of the cell. Aids in cellular support and movement. Cytoskeleton is composed of three components: 1. Microfilaments- globular protein (actin) - support and cellular contraction 2. Intermediate filaments - fibrous protein - support 3. Microtubles - globular protein (tubulin) - support and cell motility

49. Inthesecells, actinfilamentsappearlightpurple, microtubulesyellow, andnucleigreenishblue. Thisimage, whichhasbeendigitallycolored, wonfirstplaceinthe 2003 NikonSmallWorldCompetition.