Chapter 4: Anatomy of Prokaryotic and Eukaryotic cells 23-24

Prokaryote

pre-nucleus (no nucleus)

Eukaryote

contains nucleus

DNA in prokaryote vs eukaryote

prokaryote

• one circular chromosome NOT in a membrane,

• no histones

eukaryote

• linear chromosomes in nuclear membrane

• with histones

Cell walls of prokaryote

peptidoglycan walls in bacteria

pseudomurein walls in archaea

Prokaryote divides by

binary fission

Eukaryote divides by

mitosis and cytokinesis

similarities between prokaryotes and eukaryotes

• DNA

• ribosomes

• cytoplasm

• plasma membrane

• flagealla

• cytoskeleton

• cell walls

Bacillus

rod shaped

Coccus

spherical shaped

Pairs

diplo-

Clusters

staph-

Chains

strepto-

Groups of fours

tetrads

Cubelike groups of eight

sarcinae

coccobacillus

short round rod

spirochete

helical with axial filament (endoflagella)

spirillum

helical with flagella

Glycocalyx

external to cell wall, viscous and gelatinous, made of polysaccharide and/or polypeptide-

increases virulence, aids in attachment and communication

Role- attach (biofilms), prevent phagocytosis (virulence factor). Animal cells- strengnght cell surface, attachment, and communication

Two types of glycocalyx

capsule (neatly organized, firmly attached) and slime layer (unorganized and loose)

Capsules prevent

phagocytosis

What is flagella?

filamentous appendages external of the cell

What does flagella do

propel bacteria

prokaryotic is Flagella made of

protein flagellin

How does prokaryoticflagella anchor to cell wall and membrane

basal body

Eukaryotic flagella

made of tubulin in 9+2 arrangement

Peritrichous flagella

flagella distributed all over the body

Monotrichous flagella

single flagellum at one end of cell

Lophotrichous flagella

multiple flagella at one end of cell (like hair)

Amphitrichous flagella

single flagellum on each end of the cell

Flagella moving counter-clockwise

moving forward, "running"

Flagella moving clockwise

tumbling

Endoflagella (axial filaments) found in

spirochetes, ANCHORED at one end of cell

Axial filaments cause cell to move how

like a corkscrew

Fimbriae

hairlike appendages that allow for attachment

Pili

involved in motility (gliding and twitching motility) and conjugation

Gram + vs Gram -

Positive

• thick layer of peptidoglican

• neg charged teichoic acid on surface

  • lipoteichoic acid links to plasma membrane

  • wall teichoic acid links to peptidoglycan

Negative

• thin peptidoglycan

• outer membrane

• periplasmic space

atypical cell wall

• prokaryotes'

• thick or thin peptidoglycan

  • structure

• structural integrity protect lysis, separate nucleus from metabolic processes

Peptidoglycan of bacterial cell walls composed of

N-acetylglucosamine (NAG) and N-acetylmuramic acid (NAM)

Rows of peptidoglycan in gram-positive bacteria linked by

peptide cross bridges

Gram-negative cell walls protect from

phagocytes, complement, and antibiotics

Gram-negative outer membrane

lipopolysaccharide (LPS)

Lipopolysaccharides of gram negative cell wall

O polysaccharide and Lipid A

Lipid A pathology

endotoxin, causes shock

Gram-positive produce ___ and have ___ susceptibility to penicillin

exotoxins; high

Gram-negative produce ___ and have ___ susceptibility to penicillin

endotoxins; low

Acid-fast cell walls

Waxy lipid (mycolic acid) bound to peptidoglycan

Mycobacterium

Nocardia

Stain with carbolfuchsin

Archaea

grow in extreme environments and can be wall-less or walls of pseudomurein

Lysozyme

digests peptidoglycan

Penicillin on cells walls

inhibits peptide bridges in peptidoglycan

Damage to plasma membrane by

alcohols, quaternary ammonium (detergents), and polymyxin antibiotics causes leakage of cell contents

Plasmids

extrachromosomal genetic elements;

Prokaryotic ribosomes do what and are made of what

sites of protein synthesis; made of 70S subunit (50S + 30S)

inclusions and granules

storage for various purposes, such as phosphate (ATP in algae fungi protozoa), polysaccharide (energy reserves,glycogen starch), sulfur, Rubisco (co2 fix), iron oxide (destroy H2O2 which destroyes cells), gas vacuoules (protein covered cylinders that maintain buoyancy to remain at desired depth)

• lipid inclusions + sulfur→ energy reserves

Endospores

• dormant/tough/non-reproductive structure

• germination into vegetative cells

• spore-forming: bacillus and clostridium

• disease-gangrene, tetanus, botulism, food poisioning

• resistance to UV and gamma rays, desiccation, lysozome, temperature, starvation, chemical disinfectants

• Germination- return to vegetative state done by heat, moisture and food

• STAIN GREEN

• Dehyraged, DPA, calcium, ribosomes, RNA, some enzymes

Endospores produced when

nutrients are depleted;stressful environmental conditions

Sporulation

• spore septum isolates newly replicated DNA into small part of cytoplasm

• plasma membrane surrounds DNA and isolated it

• spore septum surrounds isolated portion to form forespore

• peptidoglycan layer form between membranes

• spore coat

• endospore freed

What are the cell wall carbohydrates for plants, fungi, and yeast

cellulose in plants, chitin in fungi, and mannan in yeasts

Cytoplasm

A jellylike fluid inside the cell in which the organelles and enzymes are suspended

prokaryotic cytoskeleton

-less extensive than eukaryotes, but homologous

-MreB, ParM, crescetin, FtsZ

Eukaryotic cytoskeleton made of

microfilaments and intermediate filaments gives shape and support

Eukaryotic ribosomes do what and consist of what

sites of protein synthesis using mRNA and consist of large 60S subunit and small 40S subunit (80S)

eukaryotic cell wall

• found in plants, algae, and fungi

• made of carbohydrates 

  • cellulose-plants

  • chitin-fungi

  • glucan and mannan- yeast

  • silica-algae