Introduction to the Medical Introduction to the Medical biology. Structural and biology. Structural and functional organization of a functional organization of a cell.cell.

Autor Iryna Autor Iryna Pryvrotska Pryvrotska

Questions to answerQuestions to answer

General and medical Biology as the sciences. General and medical Biology as the sciences. Characteristics of living things.Characteristics of living things. Levels of living organization.Levels of living organization. The cell theory in its modern formThe cell theory in its modern form.. Cellular level of life organization: Cellular level of life organization: -prokaryotic and eukaryotic cells-prokaryotic and eukaryotic cells -the differences between plant and animal -the differences between plant and animal

cells.cells. The main components of eukaryotic cellThe main components of eukaryotic cell..

Characteristics of living Characteristics of living thingsthings..

use energyuse energy – have a – have a metabolismmetabolism- the building up and breaking down of - the building up and breaking down of chemicals chemicals

grow and developgrow and develop become larger and more complex become larger and more complex respond to their surroundingrespond to their surrounding

reproducereproduce- produce offspring that are similar to the parents   - produce offspring that are similar to the parents   have the chemicals of lifehave the chemicals of life, carbohydrates, proteins, lipids and nucleic , carbohydrates, proteins, lipids and nucleic

acids (genetic material)  acids (genetic material)   have cellshave cells

            TheThe fundamental characteristics of living thingsfundamental characteristics of living things:: reproductionreproduction (self-reproduction)(self-reproduction), which is the process that gives rise to , which is the process that gives rise to

offspring; offspring; genesgenes (self-renewal(self-renewal) are the units of inheritance, passed prom parent to ) are the units of inheritance, passed prom parent to

offspring, that control many daily functions. offspring, that control many daily functions. Finally, Finally, populationpopulationss of living organisms adjust to environment variations of living organisms adjust to environment variations

through through evolutionevolution,, a change in the traits of a species over time a change in the traits of a species over time (self-(self-regulation)regulation)..

CELLSCELLS- are the basic units of structure and function in - are the basic units of structure and function in living things.living things.

ROBERT HOOKEROBERT HOOKE- - first to first to look at cellslook at cellsllooked at a thin section of ooked at a thin section of corkcork

ANTON VAN ANTON VAN LEEUWENHOEKLEEUWENHOEK – made his – made his own lenses made first own lenses made first compound microscope drew compound microscope drew pictures that we can still pictures that we can still identify today identify today

SchleidenSchleiden –concluded all –concluded all plants are made of cellsplants are made of cells

SchwannSchwann – concluded all – concluded all living things are made up of living things are made up of cellscells

Three main Three main levels of living levels of living organizationorganization::

Microsystem Microsystem - molecular, subcellalar, - molecular, subcellalar, cellular levels; cellular levels;

MesosystemMesosystem – tissular, organellic, – tissular, organellic, organismic;organismic;

MacrosystemMacrosystem of population and species, of population and species, biocenotical, biosheric.biocenotical, biosheric.

Cell theoryCell theory

All organisms are composed of one or more All organisms are composed of one or more cells, within which the life processes of cells, within which the life processes of metabolism and hereditary occur.metabolism and hereditary occur.

Cells are the smallest living things, the basic Cells are the smallest living things, the basic unit of organization of all organisms.unit of organization of all organisms.

Cells arise only by division of a previously Cells arise only by division of a previously existing cell.existing cell.

What are the cells?What are the cells?

Basic unit of lifeBasic unit of life PropertiesProperties - biomembrane enclosed- biomembrane enclosed - four biomolecules: proteins, polysacharides, - four biomolecules: proteins, polysacharides,

nucleic acids, lipidsnucleic acids, lipids - metabolism and energy transformation- metabolism and energy transformation Two major types:Two major types:- Prokaryotic:Prokaryotic: lack defined nucleus lack defined nucleus- Eukaryotic:Eukaryotic: contain membrane bound nucleus contain membrane bound nucleus

What are the differences between What are the differences between prokaryotic and eukaryotic cells?prokaryotic and eukaryotic cells?

Kindoms Kindoms KindomsKindoms1. Monera (Fubacteria) 1. Protista1. Monera (Fubacteria) 1. Protista2. Archaea (Archaebacteria) 2. Fungi2. Archaea (Archaebacteria) 2. Fungi 3. Plantae 3. Plantae

4. Animalia4. AnimaliaCharacteristics Characteristics CharacteristicsCharacteristics1. 1. LackLack a nuclear membrane 1. a nuclear membrane 1. HaveHave a nuclear membrane a nuclear membrane

2.2. Have no Have no membrane bound organels 2. membrane bound organels 2. Have Have membrane bound organelsmembrane bound organelsCurrent evidence indicates that eukaryotic evolved from prokaryotic between 1 Current evidence indicates that eukaryotic evolved from prokaryotic between 1

and 1,5 billion years agoand 1,5 billion years ago

What are the differences between What are the differences between plant and animal cells?plant and animal cells?

1. Chloroplast 1. Centriole1. Chloroplast 1. Centriole 2. Central vacuole 2. Lysosome2. Central vacuole 2. Lysosome 3. Cell wall3. Cell wall

Survey of organelle Survey of organelle structure and functionstructure and function Cytoplasm and cytosolCytoplasm and cytosol Plasma membrane Plasma membrane Mitochondria and plastidsMitochondria and plastids Endoplasmic reticulumEndoplasmic reticulum Golgy apparatus( complex)Golgy apparatus( complex) LysosomesLysosomes NucleusNucleus RibosomesRibosomes VacuolesVacuoles CCentriolesentrioles Cytosceleton.Cytosceleton.

Membranbound organelles

Nonmembane organelles

CytoplasmCytoplasm

Viscous contents of cellViscous contents of cell between the between the nuclear membrane and the plasma nuclear membrane and the plasma membranemembrane. . This include cell organellesThis include cell organelles

CytosolCytosol- aqueous part. - aqueous part. The semi-fluid The semi-fluid medium found in the cytoplasm.medium found in the cytoplasm. This This does not include the does not include the organellesorganelles

CytoskeletonCytoskeleton nightly organized network nightly organized network fibrous proteins that support the cell.fibrous proteins that support the cell.

MitochondriMitochondriaa A double membrane A double membrane

cellular organelle with its cellular organelle with its own circular DNA own circular DNA (prokaryote like (prokaryote like genomes) and genomes) and ribosomes. ribosomes.

It is the site of cellular It is the site of cellular respiration, a catabolic, respiration, a catabolic, exergonic, oxygen exergonic, oxygen requiring process that requiring process that uses energy extracted uses energy extracted from organic from organic macromolecules (like macromolecules (like glucose) to produce glucose) to produce ATP.ATP.

Endoplasmic reticulumEndoplasmic reticulum Extensive membranous networks Extensive membranous networks

of tubules and sacs called of tubules and sacs called cisternaecisternae

A .Rough Endoplasmic reticulum A .Rough Endoplasmic reticulum (RER)(RER)

-Studded with ribosome's.-Studded with ribosome's. -Site of protein synthesis. -Site of protein synthesis. -Carbohydrate Addition and -Carbohydrate Addition and

modificationmodification

B. Smooth Endoplasmic reticulum B. Smooth Endoplasmic reticulum (SER)(SER)

-Synthesizes lipids, phospholipids and -Synthesizes lipids, phospholipids and steroids. steroids.

-Detoxifies drugs, alcohol and poisons-Detoxifies drugs, alcohol and poisons-Carbohydrate Addition and -Carbohydrate Addition and

modificationmodification

RibosomesRibosomes

Nuclear and cytoplasmic organells. Composed of Nuclear and cytoplasmic organells. Composed of 60 % protein and 40% ribosomal RNA rRNA60 % protein and 40% ribosomal RNA rRNA

Site of protein synthesisSite of protein synthesis Can be found or as PolyribosomesCan be found or as Polyribosomes

Golgy apparatus Golgy apparatus (complex)(complex)

Stacked, flattened Stacked, flattened membranous organelle membranous organelle with sacs called cisternaewith sacs called cisternae

Modifies, stores, and Modifies, stores, and routes products from the routes products from the ER to the Plasma ER to the Plasma membranemembrane

Golgi Body & LysosomesGolgi Body & Lysosomes

  

Transport vesiclesTransport vesicles A membrane organelle A membrane organelle

that transits materials that transits materials from one part of the cell from one part of the cell to anotherto another

ER-to Golgy apparatusER-to Golgy apparatus Golgy apparatus-to ERGolgy apparatus-to ER Golgy apparatus-to PMGolgy apparatus-to PM PM-to Golgy apparatusPM-to Golgy apparatus

Lysosomes endosomesLysosomes endosomes Membrane-enclosed bag Membrane-enclosed bag

of hydrolytic enzymes of hydrolytic enzymes (digestive enzymes)(digestive enzymes)

Degradation of old cell Degradation of old cell components or ingested components or ingested materialsmaterials

Low pH (membrane Low pH (membrane proteins pumps in H+ )proteins pumps in H+ )

Degradative enzymes Degradative enzymes (nucleases, proteases)(nucleases, proteases)

Golgi body & Peroxisome Golgi body & Peroxisome which is a specialized which is a specialized form of lysosome. form of lysosome.

VacuolesVacuoles

Large membrane-Large membrane-closed sac for cellular closed sac for cellular storagestorage

Three typesThree types Food vacuole Food vacuole

(lysosomes attach)(lysosomes attach) Contractile vacuole Contractile vacuole

(Protozoons)(Protozoons) Central vacuole Central vacuole

(mature plant cell)(mature plant cell)

Plasma membranePlasma membrane

The boundary of every cell approximately 8nm The boundary of every cell approximately 8nm thickthick

Separates the living cell from its nonliving Separates the living cell from its nonliving surroundings.surroundings.

FunctionsFunctions Acts as selective barrierActs as selective barrier Regulate movement of material into and out of Regulate movement of material into and out of

the cellthe cell Cellular recognitionCellular recognition

Plasma membranePlasma membrane envelops the cell and aids in envelops the cell and aids in

maintaining its structural maintaining its structural and functional integrity. and functional integrity.

Composed of lipid bilayer Composed of lipid bilayer and associated proteins.and associated proteins.

composed of an inner composed of an inner leaflet (facing the leaflet (facing the cytoplasm) and an outer cytoplasm) and an outer leaflet (facing the leaflet (facing the extracellular environment).extracellular environment).

Membrane proteins may be Membrane proteins may be integral (are dissolved in the integral (are dissolved in the lipid bilayer) and peripheral lipid bilayer) and peripheral proteins (don‘t extend into proteins (don‘t extend into the lipid bilayer). the lipid bilayer).

Plasma membranePlasma membrane Lipid bilayerLipid bilayer is composed by is composed by

phospholipids (hydrophilic and phospholipids (hydrophilic and hydrоphobic), glycolipids and hydrоphobic), glycolipids and cholesterol. cholesterol.

Glycolipids Glycolipids are present in outer are present in outer leaflet only. They have polar leaflet only. They have polar carbohydrate residues that carbohydrate residues that extend from the outer leaflet into extend from the outer leaflet into the extracellular space, forming the extracellular space, forming part of glycocalix.part of glycocalix.

CholesterolCholesterol is located in both is located in both leaflets of the plasma membrane leaflets of the plasma membrane (2%) and assists in maintaining (2%) and assists in maintaining the structural integrity of the the structural integrity of the plasma membrane.plasma membrane.

GlycocalyxGlycocalyx is a sugar coat is a sugar coat

commonly associated commonly associated with the with the extracytoplasmic extracytoplasmic aspects of the outer aspects of the outer leaflet of plasma leaflet of plasma membrane (in animal membrane (in animal cells). cells).

Functions Functions aiding in cellular aiding in cellular

attachment to attachment to extracellular matrix extracellular matrix components components

binding of cellular and binding of cellular and enzymes to the cellenzymes to the cell

Plasma Membrane Transport Plasma Membrane Transport Processes.Processes. These processes include transport of a These processes include transport of a

single molecule (uniport) or cotransport single molecule (uniport) or cotransport of two different molecules in the same of two different molecules in the same (symport) or opposite (antiport) direction.(symport) or opposite (antiport) direction.

Passive transport includes Passive transport includes simplesimple and and facilitated facilitated diffusion.diffusion.

Neither of these processes requires Neither of these processes requires energy because molecules move energy because molecules move across the plasma membrane down across the plasma membrane down a concentration or electrochemical a concentration or electrochemical gradient.gradient.

1.1. Simple diffusionSimple diffusion transports transports small nonpolar molecules (02 and small nonpolar molecules (02 and N2) and small, uncharged, polar N2) and small, uncharged, polar molecules (H20, C02, and glycerol). molecules (H20, C02, and glycerol).

2.2. Facilitated diffusionFacilitated diffusion occurs via occurs via ion channel and/or carrier proteins, ion channel and/or carrier proteins, structures that exhibit specificity for structures that exhibit specificity for the transported molecules. It is the transported molecules. It is faster than simple diffusion.faster than simple diffusion.

3. 3. OsmosisOsmosis is the diffusion of water is the diffusion of water across a selectively permeable across a selectively permeable membrane in response to its membrane in response to its concentration gradient. concentration gradient.

Active transportActive transport is an energy-requiring process which is an energy-requiring process which

transports a molecule against an transports a molecule against an electrochemical gradient via carrier electrochemical gradient via carrier proteins.proteins.

Na+-K+pumpNa+-K+pump.. The Na+-K+ pump The Na+-K+ pump involves the antiport transport of Na+ involves the antiport transport of Na+ and K+ ions mediated by the carrier and K+ ions mediated by the carrier protein, Na+-K+ ATPase.protein, Na+-K+ ATPase.

Na+ ions are pumped out of the cell and Na+ ions are pumped out of the cell and two K+ ions are pumped into the cell.two K+ ions are pumped into the cell.

Comparison active and Comparison active and passive transportpassive transport

ExocytosisExocytosis is way that substances can is way that substances can

exit cells. exit cells. Part of the plasma membrane Part of the plasma membrane

pinches off and forms a small pinches off and forms a small membrane-bound sac, or membrane-bound sac, or vesiclevesicle, around some , around some substance. substance.

Vesicles even form around Vesicles even form around tiny cells (such as a tiny cells (such as a bacterium) and fluids. bacterium) and fluids.

In In exocytosisexocytosis,, vesicles form vesicles form inside the cytoplasm and then inside the cytoplasm and then move to the plasma move to the plasma membrane and fuse with it, so membrane and fuse with it, so that their contents are moved that their contents are moved to the outside. to the outside.

EndocytosisEndocytosis is way that is way that

substances can exit substances can exit cells. cells.

a patch of plasma a patch of plasma membrane encloses membrane encloses material at the cell material at the cell surface. surface.

it sinks in and it sinks in and pinches off, forming a pinches off, forming a vesicle that either vesicle that either transports the material transports the material into the cytoplasm or into the cytoplasm or stores it there. stores it there.

Phagocytosis and Phagocytosis and PinocytosisPinocytosis

Phagocytosis Phagocytosis ((cell cell eating) is transport eating) is transport process by which process by which amoeboid-type cells amoeboid-type cells engulf large material, engulf large material, forming an forming an intracellular vacuole. intracellular vacuole.

PinocytosisPinocytosis

When macromolecules When macromolecules are taken in by are taken in by endocytosis, the process endocytosis, the process is called is called Pinocytosis Pinocytosis (cell drinking), and the (cell drinking), and the result is formation of result is formation of vesicle. vesicle.

Both phagocytic Both phagocytic vacuoles and pinocytic vacuoles and pinocytic vesicles can fuse with vesicles can fuse with lysosomes, whose lysosomes, whose enzymes digest their enzymes digest their contents. contents.

CYTOSKELETONCYTOSKELETON Network of Network of fibersfibers through out the cytoplasm. through out the cytoplasm. Aids in Aids in cellular support and movementcellular support and movement.. Composed of three components:Composed of three components:

1.1. MicrofilamentsMicrofilaments - globular protein (actin) - support and - globular protein (actin) - support and cellular contractioncellular contraction

2.2. Intermediate filamentsIntermediate filaments - fibrous protein - support - fibrous protein - support

3.3. MicrotublesMicrotubles - globular protein (tubulin) support and cell - globular protein (tubulin) support and cell motilitymotility

In these cells, actin filaments appear light purple, microtubules In these cells, actin filaments appear light purple, microtubules yellow, and nuclei greenish blue. This image, which has been yellow, and nuclei greenish blue. This image, which has been digitally colored, won first place in the 2003 Nikon Small World digitally colored, won first place in the 2003 Nikon Small World Competition.Competition.TORSTEN WITTMANN TORSTEN WITTMANN

CENTRIOLESCENTRIOLES

found in found in animal cells only animal cells only Paired cylindrical organelles Paired cylindrical organelles

near nucleusnear nucleus

- Composed of nine tubes, - Composed of nine tubes, each with three tubuleseach with three tubules

- Involved in cellular division- Involved in cellular division

- Lie at right angles to each - Lie at right angles to each other other

NucleusNucleus The cell nucleus is a The cell nucleus is a

conspicuous membrane-conspicuous membrane-bound cellular organelle. bound cellular organelle.

It functions to:It functions to: Store genesStore genes into into

chromosomes to allow cell chromosomes to allow cell divisiondivision

TransportTransport regulatory factors regulatory factors and gene products vie and gene products vie nuclear poresnuclear pores

Produce messagesProduce messages (messenger ribonucleic acid (messenger ribonucleic acid or mRNA) that code for or mRNA) that code for proteinsproteins

Organise the incoiling of Organise the incoiling of DNADNA to replicate key genes to replicate key genes

NucleolusNucleolus

Spherical region in Spherical region in nucleusnucleus

Found in non-dividing Found in non-dividing cellscells

It is nuclear organizers It is nuclear organizers and synthesize rRNAand synthesize rRNA

Sometimes more than Sometimes more than one nucleolus presentone nucleolus present

Nuclear envelopeNuclear envelope

Encloses the nucleusEncloses the nucleus A double membrane A double membrane

perforated wit pores perforated wit pores through which through which materials enter and materials enter and leave the nucleus.leave the nucleus.

Heterochromatin -- tightly packed regions Heterochromatin -- tightly packed regions Euchromatin --- Regions where DNA is more openly Euchromatin --- Regions where DNA is more openly packed, location of most functional genes packed, location of most functional genes Chromosome banding (requires special stains)Chromosome banding (requires special stains)

Types Types of of chromochromosomessomes

Karyotype Karyotype is a diploid number of chromosomes and is a diploid number of chromosomes and it is a characteristics of the number and morphology it is a characteristics of the number and morphology of chromosomes, that is peculiarities of each species.of chromosomes, that is peculiarities of each species.

Male karyotypeMale karyotype 46=22A+XY46=22A+XY

Female karyotype Female karyotype 46=22A+XX46=22A+XX

Thank you for attention!Thank you for attention!