Part two

Question 1

Define Toxins

Answer 1

a chemical produced by pathogens that harm tissue or trigger hosts immune response that causes damage

Question 2

Exotoxins are gram positive T/F

Answer 2

TRUE :)

Question 3

Define an exotoxin

Answer 3

Proteins secreted by live pathogen and attack/destroy cellular and extracellular structures

Question 4

Examples of Exotoxins:

Answer 4

MRSA/Staph Auerous: cellulitis, abcesses, facilitis, and invasive infections (h1n1, pneumonia)
C-DIFF: grav positive killer, necrotic colon, GI symptoms and inflammation
Anthrax: makes exotoxins (inhalation)

Question 5

Define an Endotoxin

Answer 5

a gram negative bacteria; released after cell dies and the cell wall is altered ; contains LPS

Question 6

What is LPS and what is its function?

Answer 6

lipopolysaccharides found in gram negative endotoxins.

• huge role in infection
• causes acute inflammation and activites macrophages, neutrophils and pyrogens.

Question 7

What happens when there is to much LPS?

Answer 7

toxic to the body!!!!

• causes to much activity from the immune system (can be induced by antimicrobial drugs)
• systemic infections, blood coagulation = increased inflammation, drop of BP = shock and organ failure

Question 8

Cytoplasmic DNA

Answer 8

prokaryotic chromosome; one large circular molecule
HAPLOID
no nuculear membrane
may have plasmids (small chromosomes)

Question 9

What are the three roles of cytoplasmic DNA?

Answer 9

1) contains genetic material
2) transcription
3) replication

Question 10

What is the function of ribosomes?

Answer 10

process of translation (protein synthesis)

Question 11

True or false: Prokaryotic ribosomes are bigger then eukaryotic

Answer 11

FALSE ; they are smaller
P= 70S
E=80S

Question 12

Prokaryotic ribosomes are __S and they can be found in ________

Answer 12

70S / eukaryotes mitchondria

Question 13

What is the power house of the cell

Answer 13

….you should know this…

Question 14

Define an endospore

Answer 14

formed by vegetative cells in response to environmental signals that indicate a limiting factor for vegetative growth

Question 15

Are endospores formed by gram positive or gram negative bacteria?

Answer 15

gram positive

Question 16

What stress are endospores resistant to?

Answer 16

• temperature
• irridation
• acids
• disinfectants

Question 17

When do endospores germinate?

Answer 17

when the environmental stimulus STOPS

Question 18

Define horizontal gene transfer

Answer 18

acquiring genes from other microbes of the same generations (donor cells contribute part of the genome to a recipient cell)

Question 19

What are the 3 types of gene transfer?

Answer 19

1. Transformation
2. Transduction
3. Conjugation

Question 20

Define Transformation

Answer 20

naturally competent bacteria are able to take up exogenous DNA and undergo the genetic transformation
Cells that take up DNA are competent - results in alteration of cell wall and membrane to allow DNA entry
Eg. streptococcus, heamophilus, bacillus staphococcous, and pseudomonas

Question 21

What is transduction and what mediates it?

Answer 21

Gene transfer from donor to recipient by bacteriophage. Attaches to host bacterial host cells, injects genome, and directs the cell to synthesize new phages.

Question 22

What are the steps in generalized transduction?

Answer 22

1. Infection to donor
2. Phage replication and degradation of host
3. assembly of phage particles
4. Realease of phage
5. Recombination into host DNA

Question 23

Gene transfer from a donor to a recipient by direct/physical contact between cells (mediated by pilli)

Answer 23

CONJUGATION

Question 24

what are the maiting types in conjugation?

Answer 24

Fertility plasmids + = the donor

Fertility plasmid - = the recipient

Question 25

What are the steps in conjugation

Answer 25

1. Donor cell attaches to recipient with its pilus
2. Pilus may draw cells together
3. One strand of F plasmid DNA transfers to recipient
4. Recipient synthesizes complementary strand to become F+ cell with a pilus; donor synthesizes a complementary strand, restoring its complete plasmid

Question 26

What are the two different ways of controlling microbes with examples?

Answer 26

STERILIZATION: all killed- non selective

• auto claving (heat and pressure)
• ethlyne oxide (equipment)
• uv light (surfaces)
• gamma radiation

Disinfectant: liquids that kill bacterial
-phenol based
Antiseptics: skin, idodine/alchohol/isopropanol

Question 27

Antibacterial agents……

Answer 27

decrease bacteria load so that it is low enough for the immune system to take over
(makes the load managebel)

Question 28

What is an antibiotic?

Answer 28

Natural substance secreted by one microorganism against another

Question 29

Why is selectivity key in antibiotics?

Answer 29

because selectivity means that is is causing no harm to host; its only harming the bacteria
-without it = can cause harm to us

Question 30

This type of antibiotic is reversible; growth inhibition

Answer 30

bacteriostatic

Question 31

this type of antibiotic is irreversible; killing

Answer 31

bacteriocidal

Question 32

Where is antibiotic resistance more common?

a) bacteriostatic
b) penicillin
c) bacteriocidal

Answer 32

C

Question 33

In what ways does a phage cell infect a host?

Answer 33

Absorption (by tail fibers- receptor for LPS)
Irreversible attachment (baseplate)
Shealth contraction
Nucleic Acid Injection
DNA uptake

A Irrational Snake Never Dies