2014 PROKARYOTIC CELL Výukový materiál MB Tvůrce: Mgr. Šárka Vopěnková Tvůrce anglické verze: ThMgr. Ing. Jiří Foller Projekt: S anglickým jazykem do dalších předmětů Registrační číslo: CZ.1.07/1.1.36/ Tento projekt je spolufinancován ESF a SR ČR

 created by only one unseparated part (compartment)  the compartment is enclosed with the plasmatic membrane  the compartment is filled with the cytosol PROKARYOTIC CELL

 the nucleus of the prokaryotic cell :  not enclosed with nuclear membrane  it contains only double helix circular DNA = nucleotid  circular DNA represents only circular chromosome PROKARYOTIC CELL

 the cell reproduces by transverse partitioning > into two daughter cells  the cell is covered with cell wall:  the main element of the cell wall is peptidoglycan  in the cytosol there are ribosomes – the synthesis of proteins is proceeded here  one or more flagella > hollow screw-shaped threads PROKARYOTIC CELL

 a simple type of the cell  prokaryota are unicellular organisms (bacteria, cyanophyta, mycoplasmata)  size: 1-2 µm  cytoplasm poor in membrane organelles  only photosynthesis doing cyanophyta have biomembranes = thylakoids  they create neither differentiated tissues nor textures

PROKARYOTIC CELL  plentiful ribosomes > several thousands in a cell  prokaryotic ribosomes are smaller than eukaryotic ribosomes  cell inclusions are frequent here  they have not got miotic apparatus (partitioning spindles)  they have not got mitochondria !  material store:  acid beta-hydroxybutyric, glycogen and volutin  they reproduce asexually, by transverse division

PROKARYOTIC CELL  4 always present structures:  NUCLEOID  ribosomes  cytoplasmic membrane  cell wall  + cytoplasm

NUCLEOID  core equivalent  not enclosed by any covering  laid loosely in the cytosol  prokaryotic chromosome is 1000 times longer  organized in loops  one chromosome = one DNA >> genes pass in the unchanged form into the daughter cells  haploid prokaryotic cells  circular = cyclic >> it has not got free endings

PLASMIDS  small circular, double helix DNA molecules = plasmids  they carry additional, not necessary information  they penetrate excellently through the membrane and pass from one cell into another = bearers of new genes into a cell (use in genetic engineering)  they can sometimes bear enormously important genetic information (e.g. gene for resistance against antibiotics)  they bear genes enabling the conjugations of bacteria

CYTOPLASMIC MEMBRANE  function :  it separates the only part of the cell  it releases energy from organic substances!!!!  it isolates internal environment from the external  it is semipermeable  smooth but it also makes spurs = invagination of the membrane – on those grooves respiratory chain  green bacteria have bacteriochlorophyll here

CELL WALL  the only tight structure of the prokaryotic cell  it consists of peptidoglycan  above the wall there can also be a casing from proteins or polysaccharides

CYTOPLASM  very viscous  concentrated solution  cytoplasm is not divided into compartments  it misses organelles typical for eucaryotic cells

 different from eukaryotic flagellum in both the composition and in the function  a hollow formation  protein flagellin  it is anchored in the cytoplasmic membrane and cell wall – > rotary movement of the flagellum  energy for the movement of the flagellum - without ATP !!!! FLAGELLUM

WHAT KIND OF ORGANELLE IS THIS ?

PRACTISING DESCRIPTION OF PROKARIOTIC CELL

DESCRIBE THE PROKARYOTIC CELL

 KUBIŠTA, Václav. Obecná biologie. Praha: Fortuna, 2000, ISBN  CHALUPOVÁ - KARLOVÁ, Vlastimila. Obecná biologie. Olomouc: Nakladatelství Olomouc, 2010, ISBN  ZÁVODSKÁ, Radka. Biologie buněk. Praha: Scientia, 2006, ISBN  ROSYPAL, Stanislav. Nový přehled biologie. 1. vyd. Praha: Scientia, 2003, 797 s. ISBN  JELÍNEK, Jan, Vladimír ZICHÁČEK a Miroslav ŠVÁTORA. Biologie pro gymnázia: teoretická a praktická část. 2. dopl. a rozš. vyd. Olomouc: Nakladatelství Olomouc, 1998, 551 s. ISBN SOURCES