Bio Lab notebook

Question 1

Aseptic

Answer 1

area whose contamination has been minimized

Question 2

What is the goal of flaming?

Answer 2

Gently heat the air at the bottle opening
mini-microbiological force field
air more likely to come out of bottle than to fall into the bottle when the air at the opening is heated

Question 3

Bacteria are_______?

Answer 3

Prokaryotes the simples free living form

Question 4

Difference between bacteria and viruses?

Answer 4

bacteria-susceptible to antibiotics

Question 5

All bacteria?

Answer 5

Have a plasma membrane made of lipids (fats) that surround the inner workings of the bacterial cell

Question 6

Cell wall of bacteria?

Answer 6

-collection of molecules that surround the plasma membrane and give bacteria structural strength
Can have additional lipid membrane that protects them from harsh environments

Question 7

Appendages of bacteria?

Answer 7

-pili
-flagella
hairlike structures that protrude from bacteria-perform special functions

Question 8

T/F Bacteria does not have DNA?

Answer 8

False, bacteria contains genetic material.

don’t have a nucleus-free DNA or chromsomes-called nucleoid

Question 9

T/F bacteria contain ribosomes that translate the DNA sequence into protein

Answer 9

true

Question 10

What is a phage?

Answer 10

devourer of bacteria

100-200 nm

Question 11

Phages cannot replicate outside their host bacteria?

Answer 11

True

Question 12

Phages are not susceptible to antibiotics

Answer 12

True

Question 13

Phages are the most abundant life form

Answer 13

true

Question 14

Phages can survive in ________

Answer 14

any environment

-found inside and outside bacterial cells

Question 15

3 components of a phage?

Answer 15

1. Capsid
2. genetic material
3. tail

Question 16

What is the purpose of the capsid?

Answer 16

-contains genetic material

Question 17

The genetic material is ______in phages

Answer 17

double stranded dna

Question 18

What is the purpose of the tail in a phage?

Answer 18

1. allows phage to attach to bacteria

2. DNA passes through the tail into the bacterium

Question 19

“host range”of phage?

Answer 19

kinds of bacteria to which the phage can attach

Question 20

Sterile

Answer 20

Free of all living microorganisms including bacteria, fungi, viruses

Question 21

Who discovered phages?

Answer 21

Felix D’ Herelle- saw clear spots on a lawn of bacteria– plaques
added some material from a plaque to growing batch of bacteria

Question 22

What happens when a phage infects a bacterium?

Answer 22

The phage attaches to the bacterium and injects its DNA into a bacterial structure-
the empty phage structure empty and attached to bacterium-no longer infectious- called a ghost
-using the bacterium’s replication machinery-phage genomic DNA makes and assembles copies of itself until the host bacterium lyses

Question 23

To see phages?

Answer 23

Need a electron microscope

Question 24

If a phage is present?

Answer 24

It will infect one of the bacterial cells-replicate within the cell- lyse the bacterium
lysis-up to 100 new phages

Question 25

What is burst size?

Answer 25

Number of new phage released
new phage-travels through diffusion-will infect other bacteria
because of phage lysis-cloudy suspension of bacteria radiating outward from the area with the original phage.

Question 26

What does the clearing zone indicate?

Answer 26

presence of infectious phage particle

-Plaques contain billions of infectious phage particles- all identical to original phage.

Question 27

Why study phages?

Answer 27

Scientists would like to use phages to kill specific antibiotic resistant bacteria that causes disease

Question 28

Lytic phage

Answer 28

lyse all bacteria they infect

Question 29

Temperate phage?

Answer 29

1. Replicate and lyse the host bacteria they have infected like lytic phages
2. enter dormat state by incorporating their DNA into the DNA of the host

Question 30

Majority of bacteriophages___________?

Answer 30

temperate

Question 31

Prophage?

Answer 31

the phage genome incorporated into the bacterial DNA

Question 32

Lysogeny

Answer 32

Mechanism by which a naive bacterial cell becomes infected with prophage

Question 33

Lysogen

Answer 33

Bacterium that contains prophage

Question 34

How does phage infect a host bacterium?

Answer 34

1. absorption of the phage to the surface of the bacterium
2. irreversible attachment of phage to bacterial cell
3. Penetration of bacterial cell wall
4. nucleic acid injection from the phage head

Question 35

Injection of DNA?

Answer 35

DNA is linear within the phage head-it’s injected as a linear molecule-when phage DNA gets inside bacterium-circulizes