Microbiology- Chapter 4 (Prokaryotic Cells- Bacteria And Archaea)

Front 1

True or false.

Prokaryotes' genetic material in enclosed with a membrane.

Back 1

False

Front 2

What are the two big groups that are part of the prokaryotic cells?

Back 2

Bacteria and Archaea

Front 3

Size of Prokaryotes?

Back 3

× Small; <1.0-3.0 µm (micrometers) in diameter

Front 4

True or False.

Prokaryotes do not have membrane enclosed organelles.

Back 4

True

Front 5

How do prokaryotes divide?

Back 5

× Cell division by binary fission **like dividing the cell into two

Front 6

What are the external structures of Prokaryotes?

Back 6

- Glycocalyx- Capsule or Slime
- Flagella
- Fimbriae and Pili

FImbriae- attachment
Pili- Sex

Front 7

What are the internal structures of Prokaryotes?

Back 7

- Cytoplasm **Dna floats in the cytoplasm as well
- Nucleoid where dna is
- Ribosomes where the proteins are made
- Inclusion granules another piece or little pieces of dna are there as well

Front 8

What are Flagella?

Back 8

× Long, whip-like structures that extend beyond the surface of cell
× Responsible for movement
× Present in some bacteria-- *not all

Front 9

What are the arrangement of Flagella?

Back 9

× Monotrichous
- Single polar flagellum
× Lophotrichous
- Two of more flagella at one end of the cell
× Amphitrichous
- A single flagellum or tuft of flagella on each end of the cell
× Peritrichous
- Flagella distributed over the entire cell

Front 10

Describe the structure of Flagella?

Back 10

× Basal body- anchors the flagellum to the cell wall and plasma membrane
× Hook- anchors the flagellum to the cell wall
× Filament- outermost region on the flagellum, composed of the protein flagellin
× *flagellum is made by flagelly :)

Front 11

Describe attachment of flagella in gram positive and gram negative cells.

Back 11

× Gram positive
- 1 pair of rings
× Only inner pair is present
× Gram negative
- 2 pairs of rings
× Outer pair of rings is attached to the cell wall
× Inner pair (*the one that is in gram positive) anchored to the plasma membrane

Front 12

Name the two rotations of flagellum.

Back 12

Tumble- clockwise
Run- counterclockwise

Front 13

What is chemotaxis and phototaxis?

Back 13

Move towards or away from environmental stimuli- taxis.

Chemotaxis- chemical stimulus
× Bacteria contains receptors- pick up chemical stimuli

Phototaxis- light as a stimulus

Front 14

Answer.

Attractant causes movement towards stimulus, does it cause a run or tumble?

Back 14

Run

Front 15

Answer.

Does a repellent cause a run or tumbles?

Back 15

tumbles

Front 16

What is periplasmic flagella?

Back 16

Bundle of fibrils under the outer sheath. Anchored at one end of the cell and the rotation of filaments causes spiral motion.

Front 17

Describe fimbriae (attachment.)

Back 17

× Sticky, proteinaceous projections
× Used by bacteria to adhere to one another, to hosts, and to substances in environment
× May be hundreds per cell and are shorter then flagella
× Serve and important function in biofilms

Front 18

Describe Pilus (mating).

Back 18

× Long hollow tubules composed of pilin
× Bacteria typically only have one or two per cell
× Join two bacterial cells and mediate the transfer of DNA from one cell to another (conjugation)
× Also known as conjugation pili or sex pili

Front 19

What are the two types of glycocalix. (coating)

Back 19

× Slime layer- loosely attatched to the cell surface; water soluble; protects cells from drying out
× Capsule- tightly bound to the cell surface-- *cannot easily be removed

Front 20

Describe the function of capsule. (Glycocalix)

Back 20

× Protects cells from drying out
× Higher pathogenicity- may prevent bacteria from being recognized and destroyed by host phagocytes (bacillus anthracis- anthrax)
× Enables attatchment to surfaces (plant roots, water pipes—*innnercoating making the pipe smaller… ew, surface of teeth, etc.)

Front 21

What are biofilms?

Back 21

slime communities.

× Biofilms are attatched to surface
- Dental plaque, mucous membrane, surface of a rock in a pond
- Or are they freely floating- flock

Front 22

What are the layers of the cell envelope?

Back 22

- Outer membrane (some bacteria)
- Cell wall
- Cell membrane

Hint 22

HINT: Prokaryotic

Front 23

List the functions of the cell wall.

Back 23

× Surrounds the whole cell
× Protects the cell from adverse effects of the outside environment
× Withstands the pressure of the cell
× Maintains the shape of bacterium

Front 24

What is the main component of the cell wall.

Back 24

×Main component: peptidoglycan

Front 25

Describe what peptidoglycan is composed of.

Back 25

× Peptidoglycan composed of sugars:
- N-acetylglucosamin NAG
- N-acetylmuramic acid NAM
- Amino acids
× Chains of NAG and NAM attatched to other chains by tetrapeptide crossbridges

Front 26

How is the cell wall of gram + cells?

Back 26

× Thick layer of peptidoglycan (prevents the rinse out of a blue dye complex during the gram-staining: cell appear violet)
× Contains also teichoic acid
× Lipoteichoic acids anchor peptidoglycan to cell membrane

Front 27

How is the cell wall of gram- cells?

Back 27

- Thin layer of peptidoglycan
- Outer membrane
× Bilayer- phospholipids
× Channel proteins (porins)
× Lipopolysaccharide (LPS)
× During gram staining procedure, the blue dye complex is washed out (by acetone), the second dye (safranin- red) stains the cell- cell appears red

Front 28

What are the functions of the outer membrane?

Back 28

- evading phagocytosis
- Barrier to some antibiotics, lyzozyme, heavy metals…

Front 29

What is the function of porins?

Back 29

-Permit toe passage of certain molecules

Front 30

Lipopolysaccharide (LPS) are also known as ___________.

Back 30

Endotoxin.
-Released from dead cells when cell wall disintegrates
- May trigger fever, vasodilation, inflammation, shock, and blood clotting—its TOXIC
- Can be released when antimicrobial drugs kill bacteria

Front 31

How does Penicillin and Lysozymes damage cell wall?

Back 31

- Penicillin- interferes with the formation of the cell wall
- Lysozyme- enzyme that ruptures the cell wall--- it removes it

× Gram positive Bacteria+ lysozyme= protoplast
× Gram negative bateria+ lysozyme= spheroplast
o Spherical cell without cell wall

Front 32

Choose.

Mycoplasma:

- Have cell wall
-Lack cell wall

Back 32

Lack cell wall

Front 33

What are mycobacterium cell wall composed of?

Back 33

Waxy lipid

Front 34

What is the cell membrane composed of?

Back 34

- Phospholipid bilayer
- Proteins

Front 35

What does one layer of the Phospholipid bilayer consist of?

Back 35

× Hydrophilic (waterloving) heads
× Hydrophobic (waterfearing)tails

Front 36

What are the proteins in the cell membrane?

Back 36

x Integral proteins (channels)
×Peripheral proteins (enzymes)
×Glycoproteins (receptors)

Front 37

Functions of cytoplasmic membrane:

Back 37

× Controls passage of substances into and out of the cell; selectively permeable
× Site of energy production (ATP synthesis)
× Harvests light energy in the photosynthetic prokaryotes
× Site of flagella insertion
× Site of pili, fimbriae insertion
× DNA attached to one point on cytoplasmic membrane

Front 38

What does the cytoplasm consist of?

Back 38

× Consists of
- 80% water
- Proteins
- Carbohydrates
- Lipids
- Minerals

Front 39

what are plasmids?

Back 39

extrachromosomal genetic elements- small circular DNA molecules, carry genes for antibiotic resistance

Front 40

Describe the Nuclear Area of a prokaryotic cell.

Back 40

×Bacterial chromosome- a single circular molecule of DNA
×Not surrounded by nuclear membrane
×Attached to the cytoplasmic membrane
×Plasmids- extrachromosomal genetic elements- small circular DNA molecules, carry genes for antibiotic resistance

Front 41

What are ribosomes?

Back 41

× Small globular structures in cytoplasm
× Sites of protein synthesis


× Composed of 2 subunits -70S (30S(small subunit)+50S(large subunit))
× Consists of rRNA and proteins
× Targeted by some antibiotics

Front 42

Are are Inclusions?

Back 42

× Metachromatic granules- reserve of phosphate
× Polysaccharide granules
× Lipid inclusions
× Sulfur granules
× Gas vacuoles
× Polyhidroxybutirate

Front 43

Where are endospores found?

Back 43

× Found in Gr+ bacteria only

Front 44

What are endospores?

Back 44

×Resting cells- dehydrating cells with a thick cell wall
×Formed during the exposure to unfavorable conditions
×Found in Gr+ bacteria only
×Multiple-layers of spore coats provide resistance to dehydration, high temperatures, toxic chemicals, radiation
×25 million year old spore germinated
×Spores germinate into vegtative cells when put back in the favorable conditions

Front 45

What are the 3 basic shapes of Prokaryotic cells?

Back 45

× Spherical- Cocci (coccus; berries)
× Rod-shaped- bacilli
× Spiral

Front 46

Describe the different type of Cocci shapes.

Back 46

× Diplococci- in pairs
× Streptococci- in chain
× Tetrad- groups of four- divide in 2 plains
× Sarcinar- groups of 8- divide in 3 plains
× Staphylococci- grapelike clusters- multiple plains

Front 47

Describe the different types of Bacillus shapes.

Back 47

× Bacillus- single rods
× Diplobacilli- in pairs after division
× Streptobacilli- in chains after division
× Coccobacilli-

Front 48

Describe the different types of Spiral shapes.

Back 48

× Vibrio Curved Rods
× Spirilla Corkscrew- rigid
× Spirochetes helical flexibal

Front 49

Dimensions of Bacteria.

Back 49

× Average <1.0-3.0 µm in diameter
× Very small: nano bacteria 0.05-0.2 µm
× Very big: 300µm

Front 50

What is unusual about Rickettsias? ( Prokaryotic groups with unusual characteristics)

Back 50

Somewhat typical morphology, but atypical life cycle and other adaptions.
-Most are pathogens
-Alternate between mammalian host and blood sucking arthropods (fleas,life or ticks)
-Cannot survive, multiply ect outside host cell.

Front 51

What are diseases caused by Rickettsias?

Back 51

-Rocky Mountain spotted fever (transmitted by fleas)
-Endemic Typhus (transmitted by lice)

Front 52

What is unusual about Chlamydias?

Back 52

-Once considered virus due to tiny size and parasitic lifestyle.
- parasitic

Causes STD

Front 53

What is a cynobacteria?

Back 53

- Bacteria w/Gram - cell wall and general prokaryotic structure.
- Can be unicellular or occur in colonial or filamentous groupings.

Front 54

What is the specialized adaption of Cynobacteria?

Back 54

Thylakoids ( extensive internal membranes)

Also has gas inclusions, to float and increase ligth exposure. (photoynthesis)

Grow in fresh water. Some pollution resistant. Inhabit hot springs even desert soils.

Front 55

What are Archaea (the other prokaryotes)?

Back 55

Considered 3rd cell type in a seperate superkingdom ( The Domain Archaea)

-More related to Doman Eukarya
-Most primitive of ALL life forms on earth
- Extremephiles: Love extreme conditions

Front 56

How do Arcahea differ than other cells?

Back 56

- genetic sequences are found only in their rRNA
- Have unique membrane lipids and cell wall construction

Front 57

What do Methanogens do?

Back 57

Convert CO2 and H2 into methane gas (CH4)

Methane contributes to Greenhouse effect

Front 58

What are Extreme Halophiles?

Back 58

Love salt.

Require salt to grow, can multiply in sodium chloride (would destroy most cells)

Front 59

What are Psychrophilic archaeas?

Back 59

Loving cold temps.

Front 60

What are Hyperthermophilic Archaea?

Back 60

Loving high temps

Thermoplasma- lives in hot, acidic habitats in waste piles around coal mines (pH 1, temp 60C)