Bisc 410 - Characterisics Of Bacteria

Front 1

Bacteria morphology:
Coccus are typically ________ and can divide in _____ plane(s).

Back 1

Spherical; many different

Front 2

What are the five basic shapes of rod bacteria (bacillus)?

Back 2

1. Fusiform: elongated rods with tapered ends
2. Vibrio: comma-shaped
3. Filamentous: long and branching
4. Pleomorphic: many shapes
5. Coccobacillus: short (may appear like cocci)

Front 3

What are the two divisions of helical bacteria?

Back 3

1. Spirochete: thin, corkscrew shape
2. Spirillum: spiral, thicker with fewer turns

Front 4

What is the morphology of bacteria found in high salt environments like the Dead Sea?

Back 4

Square

Front 5

Rods can divide in ___ plane(s), so they can be grouped as ______ ?

Back 5

One plane; diplo and chains (strepto)

Front 6

What is a staphylo grouping of cells?

Back 6

Cells in clusters, dividing in random planes

Front 7

Bacteria in tetrad groupings divide in _______ planes.

Back 7

Perpendicular

Front 8

What type of cell grouping tends to include cells in packets of 8 to 64 cells?

Back 8

Sarcinate

Front 9

What main structures are contained in a bacterial cell?

Back 9

DNA, inclusion bodies (storage), ribosomes, cytoplasm, membrane (wall and/or capsule)

Front 10

What are two outer appendages on bacterial structures?

Back 10

Flagella and pili

Front 11

What is the difference between motility and Brownian movement?

Back 11

Motility is when bacterial cells can actively move around in a sample.
Brownian movement is vibrating movement created by bombardment of water molecules on the cell

Front 12

What is chemotaxis?

Back 12

The ability of bacteria to move in the direction of an attractant or to move away from a repellant

Front 13

What are the two types of pili in bacteria?

Back 13

1. Common pili: attach cells to each other, host cells, substrate, etc
2. Sex pili: for transfer of genetic material (DNA)

Front 14

What three things make up the cell envelope of bacteria?

Back 14

1. Capsule
2. Cell wall
3. Cell membrane (cytoplamic membrane)

Front 15

What is the chemical composition of a bacterial capsule?

Back 15

Polysaccharides and polypeptides

Front 16

What is the significance of the bacterial capsule?

Back 16

It is antiphagocytic, aids with adherence (BIOFILMS), and contains antigens for vaccines

Front 17

What are BIOFILMS?

Back 17

Communities of bacteria adhering to a surface (ex: dental plaque)

Front 18

True or false: Viruses are prokaryotes.

Back 18

False; viruses are obligate parasites - they are not cells.

Front 19

What are the four properties of the cell wall?

Back 19

1. Maintenance of shape
2. Resistance to osmotic changes
3. Gram stain rxn determination
4. Protection from environment

Front 20

What is the chemical composition of peptidoglycan?

Back 20

Repeating disaccharide polymer of NAG and NAM with tetrapeptide chain and peptide crosslinking.

Front 21

The cell walls of Gram (+) bacteria contain a lot/a little peptidoglycan, while those of gram (-) bacteria have a lot/a little peptidoglycan.

Back 21

A lot; a litle

Front 22

What type of bacteria have an outer membrane in the cell wall?

Back 22

Gram-negative

Front 23

What is the significance of an outer membrane?

Back 23

It contains LPS, which has endotoxin activity

Front 24

What is LPS?

Back 24

Lipopolysaccharide - has toxicity due to lipid A and is heat stable at 60C
In sufficient amounts, can cause endotoxic shock: fever, inadequate blood supply to vital organs, release of vasoactive compounds, and hypotension.

Front 25

What type of bacteria is wall-deficient?

Back 25

Mycoplasma (causes walking pneumonia)

Front 26

What two substances are used in wall removal or the prevention of wall formation in bacteria?

Back 26

Lysozyme and penicillin

Front 27

What does lysozyme do?

Back 27

Enzyme found in mucous secretions that cleaves the glycosidic bond betwen NAM and NAG. This weakens the bacterial wall and can cause it to lyse.

Front 28

What does penicillin do?

Back 28

Antibiotic that inhibits the last step in peptidoglycan synthesis = weakened cell wall = lysis of bacterial cells

Front 29

What type of antibiotic treatment forms protoplasts and spheroplasts?

Back 29

Penicillin

Front 30

After treatment that destroys the cell wall, gram (+) bacteria become ________ and gram (-) bacteria become _________.

Back 30

Protoplasts; spheroplasts (with outer membrane)

Front 31

What are the four steps of the Gram staining procedure?

Back 31

1. Primary staining with crystal violet dye.
2. Gram's iodine fixes violet to cell walls in gram positive bacteria.
3. Alcohol floods slide - gram positive cells remain purple.
4. The cells are counterstained with safranin ( red dye); only stains gram negative bacteria

Front 32

What makes up the cell membrane?

Back 32

Phospholipid bilayer and proteins

Front 33

What are the functions of the cell membrane (4)?

Back 33

1. Semipermeable osmotic barrier
2. Electron transport (oxidative phosphorylation - ATP)
3. Active transport (export/secretion of hydrolytic enzymes and other proteins)
4. Cell wall biosynthesis

Front 34

What are mesosomes?

Back 34

Invaginations of cytoplasmic membrane, possible role in replication or cell wall synthesis

Front 35

In what part of the cellular envelope do flagella aquire the energy they need to move?

Back 35

The cell membrane

Front 36

True or false: Bacterial ribosomes are 70S, made up of 30S and 40S subunits.

Back 36

False; 70S made of 30S and 50S subunits

Front 37

What are the two forms of bacterial nucleic acid?

Back 37

1. Circular, condensed DNA molecule (chromosome)
2. Extrachromosomal DNA (plasmids)

Front 38

Name three examples of bacterial intracellular storage materials (inclusion bodies).

Back 38

1. Glycogen
2. Poly-beta-hydroxybutyric acid
2. Inorganic polyphosphate (metachromatic granules)

Front 39

True or false: bacterial endospores are reproductive structures found in cells.

Back 39

False; they are a form of cell differentiation

Front 40

Where and why are endospores formed?

Back 40

Formed in vegetative (actively dividing) cells; used to survive nutrient limitation and other adverse effects

Front 41

Most of the medically relevant bacteria do/do not have endospores.

Back 41

Do not

Front 42

What two species of bacteria typically have endospores?

Back 42

Bacillus and Clostridium

Front 43

Bacteria with endospores tend to be highly resistant to _________.

Back 43

Drying, heat, stains, chemcals, and UV radiation

Front 44

What is the sporulation process?

Back 44

1. Vegetative stage
2. Sporulation
3. Free spore
4. Germination (when conditions are optimal again)