Intro to bacteria

Question 1

What is the difference between prokaryotes and eukaryotes?

Answer 1

prokaryotes: (lower protists)
All bacteria
-simpler, lacks a true nucleus
-undergoes binary fission replication

eukaryotes: (higher protists)
- Protozoa, fungi, most algae
- true nucleus and nuclear membrane
- multiple chromosomes
- mitotic replication

Question 2

Describe some types of bacterial morphology:

Answer 2

2 types:

1) spherical like: cocci
2) Rod like: bacilli

Question 3

The 4 types of cocci (spherical like):

Answer 3

1) Diplococci
2) streptococci
3) staphylococci
4) sarcinae

Question 4

Appearance of Diplococci:

Answer 4

2 clusters

Question 5

Appearance of streptococci:

Answer 5

chains of round bacteria

Question 6

Appearance of staphylococci:

Answer 6

grape like clusters

Question 7

Appearance of sarcinae:

Answer 7

only ever clusters of 4

Question 8

The 5 types of bacilli (rod-like)

Answer 8

1) bacili
2) cocco bacili
3) vibro
4) spirilla
5) spirochete

Question 9

What are the 3 parts of the gram positive cell wall?

Answer 9

• peptide on top
• periplasmic space in the middle
• cytoplasmic membrane on the bottom

Question 10

What are the 5 parts of the gram negative cell wall?

Answer 10

• LPS polysaccharide with TM protein and lipid A on top
• peptide
• perplasmic space
• cytoplasmic membrane on bottom

Question 11

Describe the steps of the gram stain

Answer 11

1) make a bacterial smear
2) fix cells to the slide with heat
3) stain with basic dye (crystal violet)
4) fix stain by treating with iodine potassium iodide and precipitates
5) decolorize by washing in alcohol
6) counterstain with safranin
7) decide whether gram positive or negative
- if red - negative
- if purple - positive

Question 12

List the contents of the bacterial cytoplasmic membrane

Answer 12

• nuclear material
• inclusion bodies
• ribosomes
• plasmids

Question 13

Function of the inclusion bodies:

Answer 13

storage for food and infolds on the cytoplasmic membrane

Question 14

Function of the ribosomes:

Answer 14

involved in protein synthesis

Question 15

Function of the plasmids:

Answer 15

1) used to exchange genetic material

2) circular non-chromosomal DNA

Question 16

Function of nuclear material:

Answer 16

DNA chromosomes (haploids)

Question 17

Describe bacterial cytoplasmic membrane:

Answer 17

• composed of a lipid layer between 2 protein layers
• hydrophilic on the outside
• hydrophobic on the inside
• semipermeable so easy to move contents into the cell
• involved in cellular processes

Question 18

What protects against phagocytosis?

Answer 18

the glycocalyx on the bacterial capsules

Question 19

2 functions of bacterial capsules:

Answer 19

1) enhances adherence

2) protects against phagocytosis

Question 20

What is the glycocalyx on bacterial capsules?

Answer 20

The glycocalyx is a slime layer attached to the cell wall which enables certain bacteria to resist phagocytic engulfment by white blood cells in the body

Question 21

What are thin & whip-like structures?

Answer 21

bacterial flagella

Question 22

What has locomotion in some gram positive and gram negative bacteria?

Answer 22

bacterial flagella

Question 23

where do you see bacterial flagella motility?

Answer 23

liquid or semi-solid mediums

Question 24

What are the 2 types of bacterial pili?

Answer 24

1) short attachment pili

2) long conjunction pili

Question 25

Bacterial pili is most common seen in gram ____ bacteria?

Answer 25

negative

Question 26

what are finer filament appendages only seen with electron microscope?

Answer 26

bacterial pili

Question 27

There are ___ short attachment pili where as there are ____ long conjunctival pili

Answer 27

there are numerous short pili and few long pili

Question 28

Function of short attachment pili:

Answer 28

adhesion

Question 29

function of long conjunctival pili:

Answer 29

plasmid exchange

Question 30

what is produced by bacillus app. and clostridium spp?

Answer 30

bacterial endospores/spores

Question 31

Bacterial spores are ____ to high temperatures (even boiling), most disinfectants, drying, low energy radiation

Answer 31

RESISTANT

Question 32

Bacterial endospores are:

Answer 32

resistant and dormant survival form

Question 33

TRUE OR FALSE: The endospore can survive possibly thousands of years until a variety of environmental stimuli trigger germination, allowing outgrowth of a single vegetative bacterium

Answer 33

TRUE

Question 34

Sex pili are also called?

Answer 34

long conjunctival pili

Question 35

Fimbriae are also called?

Answer 35

short attachment pili

Question 36

Steps to koch postulates

Answer 36

1) find the same pathogen in each diseased animal
2) isolate the pathogen and grow it in a pure culture
3) cause the disease in healthy animals injected with pure cultured pathogen
4) find the same pathogen present in the infected animal after the disease develops