Microbio 265 Bacterial Cell Structure

What are the characteristics of a Prokaryotic Cell?

Thin cell wall
No nucleus
All info is accessible and unpacked
No membrane bound organelles —> single cell
binary fusion to reproduce

What are the characteristics of a Eukaryotic Cell?

Thick cell walls
Nucleus with DNA
Packed with information (histones) and is inaccessible
Membrane bound organelles
Mitosis to reproduce

What are the types of Prokaryotes?

Vibrio’s = curved rods
Spirilla = Helical
Spirochetes = Helical and flexible

Arrangement of Cocci in Prokaryotes?

Diplococci = pairs
Streptococci = Chainlike
Tetrads = groups of 4
Sarcinae = groups of 8
Staphylococci = grapelike structure

What is the cell wall structure and its function?

Semi-rigid: mesh like structure
it protects from rupture during high pressure

The cell wall is the point of anchor and site of action for?

Flagella (virulence factor to invade)

Site of action for some antibiotics

What prokaryotes have little to no cell walls? (2)

Genus Mycoplasma

Archaea

Acid fast cell walls?

Mycobacterium and Nocardia, which have mycolic acid

• high concentration hydrophobic waxy lipid

Characteristics of mycolic acid

Highly resistant to disinfectants
prevents usual uptakes of dyes
Stained with Carbolfuchsin + heat

Cannot be destroyed by WBC’s

What does the cytoplasmic membrane do?

support homeostasis —> supports metabolism and growth

What is the cytoplasmic membrane made of?

Lipid bilayer of phosphate heads (-) and hydrophobic tails

• proteins allow transfer through bilayer

What is the function of the cytoplasmic membrane?

Electron Transport

• removing electrons from molecules and transporting them to oxygen to harvest energy

DNA synthesis & cellular reproduction'
Secretion of extracellular enzymes
Nutrient Transport
Cell wall synthesis

3 parts of flagella?

Filament
Hook
Basal Body

What is the filament of the flagella?

outermost part that moves liquid
made of flagellin (protein)
arranged helically

Positive Chemotaxis?

Chemoattractant = bacteria swims to food or nutrients

Negative Chemotaxis?

Chemorepellent = bacteria swims away from toxins or bad chemicals

Words (2) to describe the movement (motility) of bacteria

run and swim

What are interrupted “runs” called?

tumble

In motility, bacteria can alter..

speed, direction, rotation

What is the spirochete axial filament?

Big drill that invades tissues

• enters blood stream and becomes systemic

What are fimbriae and pili and what are they made of?

Hair-like appendages for attachment & DNA transfer

Made of pilin (protein)

Fimbriae location, virulence, 2 examples

Pole of bacteria

Adhere

Gonorrhoeae, bacterial meningitis

Describe pili and virulence

1-2 per cell, joins 2 cells for DNA movement (sex pilus)

Damage

What is the external structure of a bacteria called?

Glycocalyx (sugar coat)

What is the Glycocalyx made of?

Polysaccharide, polypeptide, or both

Name of Glycocalyx attached or loosely attached to cell wall?

Capsule
Slime Layer (biofilm)

How do endospores awaken

Bad conditions for vegetative cells (no food, high heat, etc)

Examples of endospores

Botulism, Anthrax, Tetanus

What is Germination

When an endospore becomes a vegetative cell again

What is Sporulation

When a vegetative cell becomes a endospore

Name the structure for each virulence factor
1. Enter Host
2. Adhere
3. Multiplication / Evade I.S
4. Invade / Colonize
5. Cause Damage

1. Endospore

2. Fimbriae

3. Ribosomes / Capsule

4. Endo flagella / endo flagellum

5. Pilus