Exam 2

Question 1

Anthropomorphism

Answer 1

Ascribing human form or attributes to non-human creature or objects

Question 2

Teleology

Answer 2

The belief that purpose and design are a part of, or are apparent in, nature

Question 3

What is one problem of Teleology?

Answer 3

The idea of “want”, “intent”, “motivation”.

Question 4

What happened when Spontaneous Generation was first discovered?

Answer 4

The belief that after broth was boiled, it look a lot time for organisms to grow back. However, it was discovered that it was just dust particles falling in.

Question 5

What was the swan neck?

Answer 5

It prevented dust from falling in due to shape of flask.

Question 6

What was the conclusion of Spontaneous Growth?

Answer 6

It takes a cell to make a cell

Question 7

What does “growth” refer to in Microbiology?

Answer 7

It always refers to population growth, an increase in cell numbers.

Question 8

What happens as a single cell starts to grow?

Answer 8

They increase in biomass to the point where they break into two daughter cells

Question 9

What is the name of the original cell?

Answer 9

“Mother” Cell

Question 10

What is the name of the two cells that come out of the “Mother” Cell?

Answer 10

“Daughter” Cells

Question 11

Where do cells divide in Binary Fission?

Answer 11

Right down the middle

Question 12

Where must new material be made in Binary Fission?

Answer 12

It must be made in the center of the cell

Question 13

What two problems must Binary Fission solve?

Answer 13

Division Machinery and Finding The Middle

Question 14

What is Cytokinesis?

Answer 14

When FtsZ is now present in the bacterial cell.

Question 15

What is the name of the cell division protein?

Answer 15

FtsZ

Question 16

What kind of structure does FtsZ form?

Answer 16

Forms ring-like scaffold at midcell.

Question 17

What does Cytokinesis recruit?

Answer 17

Recruits cell wall synthesis machinery

Question 18

What is the function of polymerization?

Answer 18

That different conformations may promote contractions of the ring.

Question 19

First step in FtsZ Function: Recruit Divison Machinery?

Answer 19

FtsZ polymerizes at a new division site

Question 20

Second step in FtsZ Function: Recruit Divison Machinery?

Answer 20

FtsZ recruits other “Fts” cell division proteins

Question 21

Third step in FtsZ Function: Recruit Divison Machinery?

Answer 21

Peptidoglycan synthesis machinery loads onto complex. Brings everything into the membrane so that everything can work together.

Question 22

Why are bacterial cell divison proteins called Fts?

Answer 22

“Filamentation Temperature Sensitive”

Question 23

What would happened at high temperatures to cell division to a mutant?

Answer 23

They would filament. This would suggest that they had a cell divison problem where they could grow indefinitely but they had issues with dividing.

Question 24

What does the “Min” System contain?

Answer 24

MinC and MinD

Question 25

What is MinC

Answer 25

Inhibits FtsZ polymerization

Question 26

What is MinD

Answer 26

Membrane bought anchor and activator for MinC

Question 27

Where are MinC and MinD localized?

Answer 27

To the poles.

Question 28

How are MinC and MinD kept out of the middle of the cell?

Answer 28

MinE - Topological Determinant. Forms at the end of MinC shells and inhibits MinC.

Question 29

What is Noc?

Answer 29

Nucleoid Occulsion system, prevents chromosomes from being guillotined. Coats chromosome and inhibits FtsZ from polymerizing over chromosome

Question 30

What happens in absence of MinC/D

Answer 30

Nod prevents FtsZ from forming over nucleoid, but division plane random. Results in minicells and that is lethal.

Question 31

What are Autolysins?

Answer 31

Like LytF, they are peptidoglycan remodeling enzymes. Break peptidoglycan to separate daughter cells.

Question 32

OOTW - Caulobacter Crescentus

Answer 32

 Environmental bacterium that grows in dilute water, and very low nutrients. Has a stalk (tail off the end of the cell). Stalk grows during nutrients starvation to elongate surface area.  Each division produces two different cell types; swimmer cell (cell cycle arrested) and stalked cell (actively dividing). 1. In order for it to grow, has to grow onto a stalk cell and lose the flagellum. It sticks to the surface and begins divison.

Question 33

What are the four ways to measure growth?

Answer 33

Direct Counting Viable Counting Spectrophotometry Flow Cytometry

Question 34

Advantages of Direct Counting?

Answer 34

Do not need to grow samples, works for any sample

Question 35

Disadvantages of Direct Counting?

Answer 35

Cells must be evenly distributed | Cannot distinguish which cells are dead or alive

Question 36

Viable Counting Assumption?

Answer 36

That each living cell is a colony formung unit, and will grow to become a colony.

Question 37

Counting rule for Viable Counting?

Answer 37

30-300.

Question 38

Advantages of Viable Counting?

Answer 38

Allows you to measure the number of viable cells. Has colony forming units.

Question 39

Disadvantages of Viable Counting?

Answer 39

Only works with cultureable bacteria. Assumes eachcolony originates from a single cell and problems with clumping

Question 40

How does Spectrophotometry work?

Answer 40

You shine light through the culture. The more dense the culture is, the more light that will be absorbed.

Question 41

Tudbidity definition

Answer 41

How dense the culture is to the eye.

Question 42

Why is OD600 used as the wavelength?

Answer 42

Used because you can take that number and then use viable or direct counting

Question 43

Advantages of Spectrophotometry?

Answer 43

Most rapid technique, reliable

Question 44

Disadvantages of Spectrophotometry?

Answer 44

Organisms must be cultureable. PRoblems with cell clumps are severe and indirect. Changes in size can affect reading

Question 45

What is Flow Cytometry?

Answer 45

Bacteria flows through tube and are individually counted.

Question 46

Advantages of Flow Cytometry?

Answer 46

Extremely accurate. Can measure size.

Question 47

Disadvantages of Flow Cytometry?

Answer 47

Slow, problems with clumping and dead cells.

Question 48

What is Exponential Growth?

Answer 48

When the time between generations is the same. Cells double at the same rate.

Question 49

Generation time?

Answer 49

Time required for a cell population to double in size, respresented as (g).

Question 50

What are the two types of Growth Environments?

Answer 50

Batch Culture and Continuous Culture

Question 51

What is Batch Culture?

Answer 51

* Closed system where no nutrients enter and no waste products leave. * Eventually starvation with occur where nutrient limitation will set in. * Good model for : contaminated food, some infections * Poor model for : the environment, some infections, continual flux of materials and waste products.

Question 52

What is Continuous Culture?

Answer 52

* Open system with fresh nutrients flow in and waste products flow out * Fresh nutrients flow through system, allowing for continuous growth. Stay in exponential phase for forever. * As the dilution rate increases, more nutrients flow in at a faster rate and bacteria grow faster to keep up with the faster flow. * Each bacteria has a maximum growth rate however. The bacteria cannot keep up and will get washed out.