CHARACTERISTICS OF PROKARYOTIC AND EUKARYOTIC CELLS

CHAPTER 4

2

Cellular Characteristics Prokaryotes binary fission no nucleus/nucleoid no organelles no introns genes arranged as operons cell wall of peptidoglycan

Eukaryotes mitosis/meiosis nucleus histones organelles introns cell wall of chitin or cellulose or absent 80s rRNA

3

Prokaryotic Cells Sizes

Shapes

Arrangement

4

Typical Prokaryotic Cell

Fig. 4-16ab

Gram–positive

Peptidoglycan

Cytoplasm

Membrane

Gram–negative

Peptidoglycan

Cytoplasm

Cytoplasmic membrane

Periplasm

Outer membrane(Iipopolysaccharide and protein)

6

Gram Positive Cell Wall Gram positive

Fig. 4-16c

Peptidoglycan

Cytoplasmicmembrane

TEM of bacterium

8

Gram Negative Cell Wall Gram negative

Fig. 4-16Gram–positive

Peptidoglycan

Cytoplasm

Membrane

Gram–negative

Peptidoglycan

Cytoplasm

Cytoplasmic membranePeriplasm

Outer membrane(Iipopolysaccharide and protein)

Outer membrane

Cytoplasmicmembrane

Peptidoglycan

Peptidoglycan

Cytoplasmicmembrane

PeptidoglycanPeptidoglycan

Fig. 4-23

O–polysaccharide

Outermembrane

Cellwall

Periplasm

Cytoplasmicmembrane

Corepolysaccharide

Lipid A Protein Out

Lipopoly-saccharide(LPS)

8 nm

Porin

Phospholipid

Lipoprotein

In

Peptidoglycan

11

Acid Fast Cell Wall

Acid Fast

Wall deficient

Lipid layer penetrated by hydrophobic carbol fuchsin

12

Cell Structures — Membrane

Plasma membrane

13

Cell Structures — Membrane

14

Internal Cell Structures

Cytoplasm

Ribosomes

Nuclear region

15

Inclusions

Internal Membranes

16

Endospores

17

Fig. 4-38

Fig. 4-39

Vegetative cell

Developing spore

Sporulating cell

Mature spore

Ger

min

atio

n

Fig. 4-41

Exosporium

Spore coat

Core wall

Cortex

DNA

20

Cell Structures — External

Flagellae

Fig. 4-4714 nm

Filament

Flagellin

Outermembrane(LPS)

Hook

L Ring

P Ring

Rod

Periplasm

MS Ring Basalbody

C Ring

Cytoplasmicmembrane Mot

protein

Fli proteins(motor switch)

45 nm

Motprotein

Peptidoglycan

Rod

MS Ring

C Ring

Motprotein

L P

MS

22

Cell Structures — Axial filaments Axial Filaments

23

Cell Structures — Attachment

Pili

Fimbriae

24

Cell Structures — Glycocalyx

Capsule

Slime Layer

25

Eukaryotic Cell Structure

26

Eukaryotic Cells Plasma membrane

Cytoplasm

Nucleus

27

Eukaryotic Organelles — Mt Mitochondria

28

Eukaryotic Organelles — Chloroplasts

Chloroplasts

29

Eukaryotic Organelles

Ribosomes

Endoplasmic Reticulum

30

Eukaryotic Organelles

Golgi Apparatus

Lysosomes

Peroxisomes

Vacuoles

31

Cytoskeleton and Motility Cytoskeleton Flagellae

32

Motility — Cilia

Cilia

33

Motility — Cilia

Cilia

34

Motility — Cilia

Cilia

35

Motility — Pseudopods

Pseudopodia

36

Cell Walls

Fungal cell wall (chitin) Plant cell wall(cellulose)

37

Endosymbiotic Theory

38

Endosymbiosis

39

Movement Across Membranes

Diffusion

40

Osmosis

Water movement

41

Active Transport

Active transport

42

Endo/Exocytosis