Midterm Review

Question 1

To reproduce, viruses must ___________

Answer 1

Enter a host cell

Question 2

small subunit rRNA gene sequencing has become a method of choice for both _________

Answer 2

Inferring the phylogeny of microorganisms & assigning microbes to taxonomic groups

Question 3

What will increase numerical aperture when using a microscope?

Answer 3

Immersion oil - raising the aperture achieving a higher resolution because it’s increasing the refractive index. Preventing light rays from escaping like air would

Question 4

which 2 of the following procedures are performed w/ fluorescence microscope?
- interpreting a gram stain
- visualizing photosynthetic microbes
- identifying microbes stained w/ fluorochrome
- detecting the presence of endospores

Answer 4

visualizing photosynthetic microbes & identifying microbes stained wi fluorochrome

Question 5

viruses are which kind of infectious agent?

Answer 5

Acellular made up of particles called virions

Question 6

What usually happens to cells stained for viewing under a bright field microscope?

Answer 6

cells are killed

Question 7

Photosynthetic microbes can easily be visualized by fluorescence microscopy because …

Answer 7

their pigment is naturally fluorescent

Question 8

The green fluorescent gene encodes a(n) _______ that naturally fluoresces green when exposed to light of a certain wavelength

Answer 8

Protein

Question 9

Methylene blue, crystal violet, and safranin are examples of which type of dye?

Answer 9

Basic

Question 10

Capsules are networks composed mostly of _____ that surround many bacteria

Answer 10

Polysaccharides

Question 11

Does basic dye bind to negatively or positively charged molecules? What about acidic dye?

Answer 11

Basic binds to (-)
Acidic binds to (+)

Question 12

TEM specimen are _____

Answer 12

Fixed in a plastic matrix and cut into slices

Question 13

Historically, prokaryotes were differentiated from eukaryotes by…

Answer 13

The absence of a nucleus

Question 14

Describe the controversy concerning the use of the term “prokaryote”

Answer 14

Biochemical, genetic, and genomic analyses have shown that bacteria and archaea are distinct taxa

Question 15

which group shares a basic body plan with bacteria?

Answer 15

Archaea

Question 16

For bacterial cells, the cell envelope layer that lies just outside the plasma membrane and is responsible for cell shape is called the ____?

Answer 16

cell wall

Question 17

What 3 cellular activities are associated w/ the bacterial plasma membrane?

Answer 17

synthesis of lipids and cell wall constituents, cellular respiration, and photosynthesis

Question 18

The location of the cell wall is _____

Answer 18

Just outside the plasma membrane

Question 19

which of the following cell types would normally have 2 membranes?
Gram- negative
Gram-positive

Answer 19

Gram-Negative

Question 20

What 5 components make up the cell wall in a Gram-positive bacteria?

Answer 20

stem peptide
NAM
NAG
amino acid
teichoic acids

Question 21

What 2 sugar monomers are found in peptideglycan?

Answer 21

N-acetylmuramic acid
N-acetylglucosamine

Question 22

The component of pepticdoglycan which connects the stem peptide of one pepticdoglycan chain to the stem peptide of another is referred to as the _____

Answer 22

Peptide interbridge

Question 23

which compounds typically give Gram-positive bacterial cell walls their negative charge?

Answer 23

Teichoic acid

Question 24

Teichoic acid anchors the _____ to the plasma membrane

Answer 24

Peptideglycan

Question 25

What compound links the outer membrane to the peptidoglycan in Gram-negative bacteria?

Answer 25

Braun's lipoprotein

Question 26

Name 3 characteristics about teichoic acid

Answer 26

Bound to lipids Negatively charged Bound to pepticdoglycan

Question 27

True or false: lipopolysaccharides are found only in Gram-negative bacteria

Answer 27

True

Question 28

Lipopolysaccharide is composed of _____

Answer 28

lipids & carbohydrates

Question 29

Lipid A of lipopolysaccharide is composed of ...

Answer 29

2 glucosamine sugar derivatives

Question 30

The bacterial cell wall component is found in the _____

Answer 30

outer membrane of Gram-negative bacteria

Question 31

Which component of LPS is most external in the outer membrane?

Answer 31

O antigen

Question 32

which component of LPS anchors the compound in the outer membrane of Gram-positive bacteria?

Answer 32

Lipid A

Question 33

Lipopolysaccharides are composed of what 3 components?

Answer 33

O Antigen core-polysaccharide Lipid A

Question 34

What are 4 functions of LPS?

Answer 34

contributes to negative charge stabilizes outer membrane makes a permeability barrier protects from environmental toxins

Question 35

What component of LPS can act as a toxin to people infected wl Gram-negative bacteria ?

Answer 35

Lipid A

Question 36

What's the role of porin proteins?

Answer 36

Help transport compounds across outer membrane

Question 37

A term that describes a cell bursting open

Answer 37

cytolysis

Question 38

Define plasmolysis

Answer 38

A cell shriveling up in hypertonic solutions

Question 39

The target of lysozyme is ____

Answer 39

bonds between NAM & NAG

Question 40

which of the following structures can be associated w/ DNA uptake? Flagella pili Cilia pseudopodia

Answer 40

pili

Question 41

Peritrichous refers to ______

Answer 41

Distribution of flagella around cell

Question 42

Pill or fimbriae function to . . .

Answer 42

Import DNA to cytoplasm Function in motility Attach to surfaces

Question 43

the bacterial flagellum is anchored to the cell envelope by the ______

Answer 43

Basal body

Question 44

The filament of a flagellum is composed of repeating protein subunits called _____

Answer 44

Flagellin

Question 45

Sex pili are associated w/ which process?

Answer 45

conjugation

Question 46

What's the term for a monotrichous bacterial flagellum if it's located at one end of a rod-like cell?

Answer 46

polar flagellum

Question 47

What's the longest component of the bacterial flagellum?

Answer 47

Filament

Question 48

In archaeal plasma membranes, hydrocarbons are attached to glycerol by _____ links, while in bacterial and eukaryotic plasma membranes hydrocarbons are attached by _____ links

Answer 48

Ether, ester

Question 49

How many basal body rings are found in Gram-negative bacteria?

Answer 49

Four

Question 50

In which ways do tetraether lipids differ from diether lipids?

Answer 50

Tetraether lipids are longer and more rigid

Question 51

Where does a flagellum filament add subunits to grow in length ? .

Answer 51

The tip, by the filament cap

Question 52

Branching of the hydrocarbon chains in archaeal lipids mostly affects which two membrane properties?

Answer 52

Fluidity & Permeability

Question 53

Why isn't Gram-staining used for the study of archaea?

Answer 53

The observed color of cells doesn't correlate w/ cell wall structure

Question 54

which term best describes a microscope for which the image stays in focus even when the objective lenses are changed?

Answer 54

parfocal

Question 55

In which type of staining is the background stained but not the cells?

Answer 55

Negative

Question 56

Acid-fast organisms have lipids constructed of _____ acid in their cell walls

Answer 56

Mycolic

Question 57

Located outside of the cell membrane, the _____ aids in resistance to phagocytosis

Answer 57

capsule

Question 58

Which 3 features distinguish archaeal cells from bacterial?

Answer 58

Different rRNA Sequences unique membrane lipids Distinctive cell walls

Question 59

Bacterial cells that are variable in shape and lack a single characteristic form are called _____ in shape

Answer 59

Pleomorphic