Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Microbiology > EXAM 1: LO 3, 4 & 5 > Flashcards

EXAM 1: LO 3, 4 & 5 Flashcards

You may prefer our related Brainscape-certified flashcards:
Biology 101 flashcards
1
Q

Exopolysaccharide

A

a polysaccharide secreted by an organism into the environment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Chemotaxis

A
  • Movement of a motile cell or organism in a direction corresponding to a gradient of increasing or decreasing concentration of a particular substance
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Adhesin

A

cell surface components or appendages of bacteria that facilitate bacterial adhesion/adherence to other cells or to inanimate surfaces

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Signal Transduction

A

a mechanism that converts a mechanism/chemical stimulus to a cell into a specific cellular response

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Where does DNA replication and protein synthesis occur in prokaryotes? What does this link?

A

The cytoplasm
Transcription/translation are linked

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Where does DNA replication occur in eukaryotes? What about translation (protein synthesis)?

A
  • DNA replication (transcription) occurs in the nucleus
  • Translation occurs in the cytoplasm for protein synthesis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Eukaryotic cells include what kingdoms?

A

Composed of algae, protozoa, fungi, animals, and plants

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Prokaryotic cells include what

A

Include bacteria and archaea

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Specify the exact shapes for prokaryotic cells

A

Cocci (spherical)
Bacilli (rod)
Spirochete (spiral)
Vibrio (comma)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Prokaryotes External Structures

What are glycocalyces (Capsules & EPS)? What are they composed of?

A
  • The gelatinous, sticky substance surrounding the outside of the cell
  • Composed of polypeptides, polysaccharides, or both
  • Can be rigid or flexible, integral, or peripheral
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Prokaryotes External Structures

Capsules

A
  • Firmly attached to the cell surface
  • Composed of polypeptides and polysaccharides
  • May prevent bacteria from being recognized by host
  • Much more defined than EPS on the surface of the cell
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Prokaryotes External Structures

EPS

A
  • Loosely attached to cell surface
  • Promotes attachment to surfaces
  • More diffuse on the surface of the cell, compared to the capsule
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Prokaryotes External Structures

Flagella is composed of what?

A

Filament, Hook and Basal Body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Prokaryotes External Structures

Flagella: Filament?

A
  • Extends from cell surface to the tip
  • Hollow, rigid cylinder
  • Composed of protein flagella
  • Some bacteria have sheath around filament
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Prokaryotes External Structures

Flagella: Hook?

A

Links filament to basal body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Prokaryotes External Structures

Flagella: Basal Body ?

A

Anchors filament & hook to cell wall by a rod & series of either 2 or 4 rings

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Fimbriae function

A
  • Responsible for motility and adherence
  • Twitching motility (nondirectional)
  • Sticky, bristle-like projections that are shorter than flagella
  • Contains adhesin
  • Mediate attachment to substances in the environment
  • Required for biofilm formation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Flagella and fimbriae require for _______

A

swarming

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

_______ is often the initial step of persistent infection

A

Adherence

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Pili function
Composed of what?

A
  • Responsible for conjugation
  • Tubules composed of pilin
  • Longer than fimbriae but shorter than flagella
  • Not universal→ Absent in Gram +
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Conjugation is what

A

process by which one bacterium transfers genetic material to another through direct contact

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Eukaryotes External Structures

Glycocalyses

A
  • Never as organized as prokaryotic capsules
  • Help anchor animal cells to each other
  • Strength cell surface
  • Provide protection against dehydration
  • Function in cell to cell recognition & communication
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Eukaryotes External Structures

Explain cell wall components of eukaryotic orgs.

A

Plants: cellulose in cell wall
Fungi: cellulose, chitin, and/or glucomannan in cell wall
Algae: a variety of polysaccharides in the cell wall

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Eukaryotes External Structures

How do eukaryotic flagella differ structurally and functionally from prokaryotic flagella?

A
  • Within the cytoplasmic membrane (undulate)
  • They have a filament
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Prokaryotes Cytoplasmic Membrane

Bacterial cytoplasmic membrane function

A
  • Interface with the environment
  • Signal transduction
  • Maintain concentration & electrical gradient (energy)
  • Transport → Selectively permeable
26
Q

Prokaryotes Cytoplasmic Membrane

Bacterial cytoplasmic membrane structure

A

Phospholipid bilayer
Gram (+) only has a plasma membrane
Gram (-) has an inner & outer membrane

27
Q

What is it and what are the components of the fluid mosaic model

A
  • Describes the structure of the plasma membrane as a mosaic of components
  • Includes: Phospholipids, cholesterol, proteins, and carbohydrates—that gives the membrane a fluid character
28
Q

Prokaryotes Cytoplasmic Membrane

Periplasm

A

space between the inner and outer membrane in Gram-negative bacteria.

29
Q

Prokaryotes Cytoplasmic Membrane

Archaeal cell walls / cytoplasmic membrane

A
  • Most archaea have cell walls
  • Do not have peptidoglycan → contain a variety of specialized polysaccharides and proteins
  • All archaea have cytoplasmic membranes (same functions as bacterial cytoplasmic membranes)
30
Q

Eukaryotes Cytoplasmic Membrane
contains what?
Function?

A
  • All eukaryotic cells have cytoplasmic membranes
  • Are a fluid mosaic of phospholipids and proteins
  • Contain steroids to help maintain fluidity
  • Contain regions of lipids and proteins called membrane rafts
  • Control movement into and out of the cell
31
Q

Prokaryotes Cytoplasm

List and characterize the components of the bacterial cytoplasm

A

Metabolic processes occur here
DNA replication, transcription & translation occurs

32
Q

Prokaryotes Cytoplasm

What are the non-membranous organelles of bacterial cytoplasm? Functions?

A

1) 70S (50&30) Ribosomes → translation (protein synthesis)
2) Cytoskeleton → plays a role in forming the cell’s basic shape
3) Nucleoid
4) Inclusions
5) Endospores

33
Q

What are endospores?

A
  • Unique structures produced by some bacteria that are a defensive strategy against unfavorable conditions
  • Function → ensures the survival of a bacterium through periods of environmental stress.
  • Dormant, non reproductive, durable
34
Q

What are Inclusions

A

Cytoplasmic raw materials that include reserve deposits of chemicals

35
Q

Archaeal cytoplasm structures

A

70S ribosomes
Fibrous cytoskeleton
Circular DNA

36
Q

How does Archael cytoplasm differ from the bacterial cytoplasm?

A
  • Different ribosomal proteins
  • Different metabolic enzymes to make RNA
  • Genetic code is more similar to eukaryotes
37
Q

Eukaryotes cytoplasm structure

A

NO FIMBRIAE IN EUK.
80S Ribosomes (larger than prokaryotic ribosomes)
Cytoskeleton
Flagella
Cilia
Membranous organelles

38
Q

Eukaryotic cytoskeleton

A
  • Made up of tubulin microtubules, actin microfilaments, and intermediate filaments
  • Anchors organelles
  • Produces basic shape of the cell
39
Q

Eukaryotic Flagella

A
  • Flagella are within the cytoplasm (flagella of prokaryotes are external)
  • Shaft composed of tubulin arranged to form microtubules
  • Filaments are anchored to cell by basal body (no hook)
  • Maybe single or multiple flagella
  • Function: motility BUT DO NOT ROTATE, but undulate rhythmically
40
Q

Eukaryotic cilia

A
  • Shorter and more numerous than flagella
  • Coordinated beating propels cells through their environment (MOTILITY)
  • Also used to move substances past the surface of the cell
41
Q

Cell wall composition of plants, fungi, algae and bacteria

A

Plants Cell Wall → cellulose in cell wall
Fungi Cell Wall → cellulose, chitin, and/or glucomannan in cell wall
Algae Cell Wall → a variety of polysaccharides in the cell wall
Bacterial Cell wall → peptidoglycan in cell wall

42
Q

What is bacterial wall function?

A
  • Responsible for shape & rigidity
  • Provide structure and shape and protect the cell from osmotic forces
  • Protects against some antimicrobial drugs & targeted by others
  • Can be Gram + or Gram -
43
Q

Discuss the function of flagella.

A
  • Are responsible for movement
  • Have long structures that extend beyond cell surface
  • Are not present on all bacteria
44
Q

Discuss the structure of flagella: filament

A
  • Extends from cell surface to the tip
  • Hollow, rigid cylinder
  • Some bacteria have a sheath around the filament
45
Q

Discuss the structure of flagella: Hook

A

Links filament to the basal body

46
Q

Discuss structure of flagella: basal body

A
  • Anchors filament and hook into the cell wall by a rod and a series of either two or four rings of sensory and motor proteins that make it rotate
  • ROTATION, not undulation
47
Q

List and describe the different types of flagellation

A

Peritrichous: covers the surface
Monotrichous: single polar flagellum
Lophotrichous: tufted bunch at one pole
Amphitrichous: single flagellum at both poles
Endoflagella (on spirochete): Axial filament wraps around, causing a spiral/corkscrew shape

48
Q

Explain swimming, what structure does it require?
Explain counter/clockwise

A
  • require flagella
  • rotation propels bacterium through the environment
  • not random: response to stimuli (moves toward/away from it)
    Counterclockwise: run → run towards stimuli
    Clockwise: tumble
49
Q

What is taxis?

A
  • Movement in response to stimuli
  • Towards chemical gradient
  • In the presence of an attractant tumbling frequency is reduced and runs in direction of attractant are longer
50
Q

Explain twitching, what structures does it require?

A
  • requires fimbriae
  • Like a stress response, doesn’t matter which direction, just needs to move
51
Q

Explain swarming, what structures does it require?

A
  • Flagella & fimbriae are required
  • Many bacteria traveling in the same direction/pattern to a food source/attractant at once
52
Q

What is LPS

A

IN GRAM NEGATIVE CELLS
- Contributes to neg change on the cell surface
- Stabilizes outer membrane
- Contributes to the attachment on surfaces & biofilm formation
- Protection against host defenses (O antigen) outer portion of LPS
- Can act as an endotoxin (lipid A)

53
Q

Gram staining main purpose

A
  • Common technique used to differentiate two large groups of bacteria based on their different cell wall constituents.
  • Does this by coloring them pink or purple
54
Q

Why are gram negative bacteria stained pink?

A
  • Attributed to a thinner peptidoglycan wall
  • Does not retain the crystal violet during the decoloring process
55
Q

Describe the structure of peptidoglycan

A
  • Peptidoglycan is a polysaccharide (a derivative of glucose)
  • Has alternating units of NAG (N-acetylglucosamine) & NAM (N-acetylmuramic acid)
  • Peptide cross-bridge occurring off of NAM → binds to other NAG/NAM polysaccharide chains
  • This is where we get the rigidity from
56
Q

What color is NAM

A

Pink

57
Q

Spell NAG

A

NAG (N-acetylglucosamine)

58
Q

Spell NAM

A

NAM (N-acetylmuramic acid)

59
Q

Discuss the composition of the cell wall in Mycobacteria

A
  • Resistant to Gram stain procedure
  • Due to the presence of mycolic acid on the cell wall
  • The layer of mycolic acid on the cell wall is described as waxy: has a thin layer of peptidoglycan (but can not be considered gram -)
  • Poor absorption of nutrients
  • Mycobacterium is the most common ex.
60
Q

______ bacteria is resistant to gram stain procedure

A

Acid fast

Microbiology (14 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions