Bacterial Structure and Function

Question 1

antony van leeuwenhock

Answer 1

first to visualize microorganisms via microscope

Question 2

louis pasteur

Answer 2

proved spontaneous generation of bacteria doesn’t occur

Question 3

robert koch

Answer 3

“single most important contribution to medical science”

importance of washing your hands

Question 4

joseph lister

Answer 4

invented antiseptic surgery

Question 5

kochs postulates

Answer 5

1 the specific organism should be shown to be present in all cases of labortory animals suffering from a specific disease but should not be found in healthy animals

2 specific microorganism should be isolated from diseased animal and grown in culture

3 this isolated microorganism should be able to reinfect a healthy animal

4 should be able to re-culture from this newly infected animal

Question 6

molecular kochs postulates

Answer 6

1 identify gene or gene product

2 show that it is present in illness and not in health

3 show that disrupting gene disrupts virulence

4 show that inducing gene causes virulence

5 immune responds to gene products

6 gene/protein expressed in vivo

Question 7

classes of microorganisms

Answer 7

algae, fungi, protozoa, bacteria

Question 8

bacterial characteristics

Answer 8

many pathogens,

many require organic compounds for energy,

some non-pathogens are photosynthetic,

all have a rigid cell wall,

unique characteristics compared to other classes

Question 9

differences between prokaryotes and eukaryotes

Answer 9

eukaryotes-

chromosomes,
nucleus
mitosis
mitochondria
no cell wall

prokaryotes- 
1 circular chromosome, 
no nucleus, 
no mitosis
no mitochondria- use cell wall
use flagella for motility
cell wall

Question 10

h-antigen

Answer 10

serotype to a particular flagellum

Question 11

bacterial cell wall composition

Answer 11

composed of peptidoglycan, containing

N-acetyl muramic acid
N-acetyl glucosamine,
D- amino acids
other AAs not found in eukaryotes

Question 12

how large are bacteria

Answer 12

1 um

Question 13

three general morphological types of bacteria

Answer 13

spherical- coccus

rod shaped- bacillus

spiral shape

Question 14

why is the arrangement of cells important?

Answer 14

can be identifying features of division

ex. streptococci divide along the same axis forming chains, while staphylococci form irregular clusters

Question 15

nucleoid

Answer 15

DNA inside bacteria, but unbound by membrane

Question 16

describe the outer bacterial boundaries (wall, membrane etc.)

Answer 16

inner most- cell membrane

middle- cell wall

outer- outer membrane

capsule

periplasmaic space- b/t cell wall and outer membrane

Question 17

cytoplasm contents in bacteria

Answer 17

ribosomes (different than eukaryotes)

Question 18

functions of cell membrane

Answer 18

1 contains oxidative enzymes for energy

2 cell wall synthesis

3 transport

4 secreting toxins

5 pump out select antibiotics

Question 19

describe the structure of the cell wall

Answer 19

cross linked peptidoglycans- NAM residues crosslinked via peptide bridges and NAG residues

Question 20

what happens when you destroy the cytoplasmic membrane?

Answer 20

destroys the proton gradient

Question 21

difference between gram positive and negative

Answer 21

positive- cell wall is outer most layer. has teichoic acids

negative- has an outer membrane. has lipoproteins on cell wall, and LPS on the outer membrane

Question 22

o-antigen

Answer 22

LPS- is an endotoxin bound to outer membrane

composed of polysaccharide

Question 23

penicillinases

Answer 23

found in periplasmic spaces of gram negative bacteria

Question 24

capsule

Answer 24

not necessary- but protective (antiphagocytic)

polysaccharide

often target of Abs

Question 25

flagella

Answer 25

comprised of flagellin polymer

8-12 um long

amount and location of flagella can be identifying

use for motility

Question 26

pili/fimbrae

Answer 26

small surface appendages

main function is adherence

F-pili is necessary for reproduction

polymer of pilins

Question 27

biofilms

Answer 27

adhesion via glycocalyx

Question 28

spores

Answer 28

gram positive rods are only pathogens that form spores

dormant state that bacteria forms in lack of nutrients

very resistant- presence of dipiconlinic acid

killed by very high heat

Question 29

secreted factors

Answer 29

exotoxins, proteases, lipases