Chapter 3: Cell Structure And Function

Question 0

In the early 20th century, the cell was envisioned as a…

Answer 0

Bag of soup full of floating ribosomes and enzymes

Question 1

3 shared bacterial traits:

Answer 1

1. Thick, complex outer envelope
2. Compact genome
3. Tightly coordinated cell functions

Question 2

________ consists of a gel-like network

Answer 2

Cytoplasm

Question 3

______ encloses the cytoplasm

Answer 3

The cell membrane

Question 4

______ covers the cell membrane

Answer 4

Cell wall

Question 5

What is the non-membrane bound area of the cytoplasm that contains the chromosome in the form of looped coils?

Answer 5

The nucleoid

Question 6

External helical filament whose rotary motor propels the cell

Answer 6

Flagellum

Question 7

What must first take place in order to isolate and study cell parts?

Answer 7

Cell fractionation

Question 8

4 types of cell fractionation

Answer 8

1. Mild detergent
2. Sonication
3. Enzymes
4. Mechanical disruption

Question 9

A key tool of subcellular fractionation is the….

Answer 9

Ultracentrifuge

Question 10

What does centrifugation do?

Answer 10

Separates particles by size

Question 11

Chemical components shared by all cells:

Answer 11

1. Water
2. Essential ions
3. Small organic molecules
4. Macromolecules

Question 12

The structure that defines the existence of a cell is the…

Answer 12

Cell membrane

Question 13

Membranes have approximately equal parts of…

Answer 13

Phospholipids and proteins

Question 14

A phospholipid consists of…

Answer 14

Glycerol with ester links to two fatty acids and a phosphoryl head group

Question 15

The two layers of phospholipids in the bilayer are called…

Answer 15

Leaflets

Question 16

Membrane protein function:

Answer 16

1. Structural support
2. Detection of environmental signals
3. Secretion of virulence factors and communication signals
4. Ion transport and energy storage

Question 17

Small molecules such as ___ and ___ easily permeate the membrane by _______.

Answer 17

O2; CO2; diffusion

Question 18

Osmosis

Answer 18

The diffusion of water across a membrane

Question 19

Protein transporters are needed to…

Answer 19

Transport polar and charged molecules across the cell membrane

Question 20

Molecules move along their concentration gradient in

Answer 20

Passive transport

Question 21

Molecules move against their concentration gradient in

Answer 21

Active transport

Question 22

In eukaryotic membranes, the reinforcing agents are ______, such as ______.

Answer 22

Sterols; cholesterol

Question 23

Hopanes/hopanoids

Answer 23

Membrane-reinforcing agents in bacteria

Question 24

Ether links between glycerol and fatty acids are in...

Answer 24

Archaea

Question 25

In Archaea, hydrocarbon chains are branched...

Answer 25

Terpenoids

Question 26

The most common structural support is the

Answer 26

Cell wall

Question 27

The bacterial cell wall, or ______, consists of...

Answer 27

Sacculus; a single interlinked molecule

Question 28

Most bacterial cell walls are made of...

Answer 28

Peptidoglycan (or murein)

Question 29

Peptidoglycan consists of:

Answer 29

1. Long polymers of two disaccharides | 2. These are bound to peptides of 4 to 6 amino acids

Question 30

Why are the enzymes responsible for peptidoglycan biosynthesis excellent targets for antibiotics?

Answer 30

Peptidoglycan is unique to bacteria

Question 31

How does penicillin work?

Answer 31

It inhibits the transpeptidase that cross-links the peptides

Question 32

How does vancomycin work?

Answer 32

It prevents cross-bridge formation by binding to the terminal D-Ala-D-Ala dipeptide

Question 33

How does the widespread use of antibiotics effect microbes?

Answer 33

It selects for evolution of resistant strains

Question 34

The _____-______ bacteria have multiple layers of peptidoglycan

Answer 34

Gram-positive

Question 35

Composition of the capsule:

Answer 35

1. Polysaccharides | 2. Glycoproteins

Question 36

Function of the capsule:

Answer 36

Protects cell from phagocytosis

Question 37

Is the capsule found in gram-p or gram-n cells?

Answer 37

Both

Question 38

An additional protective layer commonly found in free-living bacteria and archaea

Answer 38

S-layer

Question 39

S-layer composition:

Answer 39

Crystalline layer of thick subunits consisting of protein or glycoprotein

Question 40

How much peptidoglycan is in a gram-negative cell?

Answer 40

Thin layer of 1 or 2 sheets

Question 41

What are lipopolysaccharides?

Answer 41

Lipids in the outer facing leaflet of gram-n cells that are toxic when released from the cell membrane

Question 42

Where are the lipoproteins in gram-n bacteria?

Answer 42

On the inner leaflet

Question 43

What does the outer membrane do in gram-n bacteria?

Answer 43

It confers defensive abilities and toxigenic properties on many pathogens

Question 44

What is FtsZ?

Answer 44

A protein that gives bacteria the z-ring

Question 45

MreB

Answer 45

Forms a coil inside rod-shaped cells

Question 46

CreS

Answer 46

"Crescentin" - forms a polymer along the inner side of a crescent-shaped bactera

Question 47

In bact. that appear superficially symmetrical, polar differences may appear at...

Answer 47

Cell division

Question 48

Extensively folded intracellular membranes used for photosynthesis

Answer 48

Thylakoids

Question 49

Bacterial structures that help control buoyancy

Answer 49

Gas vesicles

Question 50

Carboxysomes

Answer 50

Polyhedral bodies packed with the enzyme Rubisco for CO2 fixation

Question 51

What do bacteria use sulfur for?

Answer 51

Oxidation

Question 52

What are glycogen, phb, and pha used for and where are they stored?

Answer 52

Energy; in the storage granules

Question 53

Orient the swimming of magnetotactic bacteria

Answer 53

Magnetosomes

Question 54

Straight filaments of pilin protein

Answer 54

Pili or fimbriae

Question 55

Membrane-embedded extensions of the cytoplasm

Answer 55

Stalks

Question 56

What do stalks do?

Answer 56

Secrete adhesion factors called holdfasts

Question 57

Intercellular connections that pass material from one cell to the next

Answer 57

Nanotubes

Question 58

The type of cell that has flagella randomly distributed

Answer 58

Peritrichous

Question 59

Have a single flagella

Answer 59

Monotrichous

Question 60

Have flagella at the ends

Answer 60

Lophotrichous

Question 61

Each flagellum is a spiral filament of protein monomers called..

Answer 61

Flagellin

Question 62

The flagellum is rotated by a motor driven by...

Answer 62

The proton motive force

Question 63

The movement of a bacteria in response to chemical gradients

Answer 63

Chemotaxis

Question 64

Repellents cause ____ rotation

Answer 64

CW

Question 65

Attractants cause _____ rotation

Answer 65

CCW

Question 66

Alternating runs and tumbles cause a

Answer 66

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