Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

microbio > lecture 2&3 > Flashcards

lecture 2&3 Flashcards

(51 cards)

Start Studying
1
Q

what does Cooci look like? Bacilli? Vibros, spirilla, spirochetes, and pleomorphic?

A

Vibrios - curved/comma shaped
Spirilla - rigid spiral-shaped
Spirochetes - flexible spiral-shaped
Pleomorphic - organisms that are variable in shape
Cocci - single or arranged spheres
Bacilli - rods

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

what is the purpose of the different shapes of bacteria?

A

protective mechanisms or aid infection

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

what are three common bacterial features, and what does each do?

A
  • Cell envelope - plasma membrane and surrounding layers external to it
  • plasma membrane - innermost and selectively permeable membrane and interacts with external environment
  • cell wall - maintain shapes, protects cells from toxic materials and osmotic lysis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Bacterial lipids:

A
  • The plasma membrane - made up of amphipathic lipids
  • Hopaniods - hydrophobic molecules similar to cholesterol (impacts fluidity and shape and forms functional microdomains for protein assembly)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what does the cross-linking mean for peptidoglycan and what are the two types?
- what does it alternate?

A
  • The stands have a helical shape and are crosslinked for strength
  • Direct cross-link - between amino and carboxyl groups
  • Indirect cross link - peptide interbridge may form
  • NAG and NAM - alternating sugars
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what color does gram-positive stain?
- what kind of membrane?
- peptidoglycan?
- may contain?

A
  • purple
  • primarily composed of peptidoglycan
  • has teichoic acids
  • periplasm (between the plasma membrane and cell wall) and a few proteins
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what are teichoic acids?

A
  • negatively charged
  • These make sure to maintain the cell envelope
  • Protect from environmental substances
  • May bind to host cells to initiate infection
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

gram negative
- stain?
- peptidoglycan?
- OM?

A
  • pink or red
  • thin layer of peptidoglycan surrounded by an outer-membrane composed of lipids, lipoproteins and lipopolysaccharides
  • no teichoic acids
  • outer membrane outside thin peptidoglycan, connected to peptidoglycan by brauns liporprotins
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

LPS - lipospolysaccarides

A
  • contribute to a negative charge on the surface
  • Helps stabilize the outer membrane
  • Host defense protection
  • Acts as endotoxin
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what are the the component that make the ooutside of the cell wall?

A

capsules
slime layers
S layer
bacterial cytoplasm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what are capsules?

A
  • like a jacket
  • Are well organized and cannot be easily removed from the cell
  • Usually composed of polysaccharides
  • Protective function - resistant to phagocytosis, protects from desiccation, and excludes viruses and detergent
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what are slime layers?

A
  • Similar to capsules but they diffuse, unorganised, and easily removed
  • May facilitate motility
  • Cheap version (like vasleine instead of jacket)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

S (surface layer)

A
  • Regularly structures self-assembling layers of protein or glycoprotein
  • Protect from ion/pH fluctuations, osmotic stress, enzymes, predation, host defense - these are only in cells with extreme environments
  • Maintains shape and rigidity
  • Promotes adhesion to surface
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

intracytoplasmic membranes

A
  • plasma membrane in-foldings
  • observed in photosynthetic bacteria and high respiratory activity
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

bacterial cytoskelton

A
  • Protein filaments that participate in cell division, localize proteins, and maintain cell shape
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

gas vacuoles

A

Involved in bacterial movement
Provide buoyancy to aquatic bacteria
Made of aggregates of hollow, cylindrical gas vesicles

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

ribsomes?

A

Complex protein/RNA structure that have Sites of protein synthesis ( 70s)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Nucleoid

A

Usually not membrane-bound
- Usually 1 closed circular ds DNA molecule/chromosome
- supercoiling and nucliode proteins aid in folding and structures

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

plasmid

A

Small, closed, circular, independent DNA molecules
Carry genes that can confer a selective advantage in some situations

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

what are the three external structures? purpose?

A
  • fuction in protection, attachment to surfaces , HGT, cell movement
  • fimbriae/pili
  • sex pilli
  • flagella
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what are fimbira/pili?

Study These Flashcards
A

Short thin hair-like, protein appendages
Can mediate attachment to surfaces, motility, and DNA uptake

22
Q

sex pili?

Study These Flashcards
A

Longer, thicker, less numerous
Required for conjugation
More defined hollow and produces genetic variation

23
Q

Flagella
function and what it looks like?

Study These Flashcards
A
  • Threadlike, locomotor appendage extending outward from the plasma membrane and cell wall
  • motility, attachment to surface, virulence factor (causes disease)
24
Q

what are the three parts of the bacterial flagella?

Study These Flashcards
A

1.) filament /flagellum - extends from cell surface to top
2.) Hook - short flexible segment
3.) Basal body - embedded in cell envelope

25
what is the two-part motor-producing technique?
- Rotor - moving parts, C-ring ring interact with stators and connects to the rod - Stator- stationary parts, capture PMF through the membrane to generate torque and drive rotation
26
what are two ways that flagella can move?
- rotates like a propeller CCW rotation = forward movement CW disrupts run = tumble
27
how can flagella move?
- chemotaxis: movement towards a chemical attraction or away from chemical repellant - Chemoreceptors transmit signals throughout the chemosensing system - detect external signals and determine whether it should run or tumble
28
swarming ?
- long collective run togetehr (lot together) - Cells move faster than swimmers and have increased resistance to antibiotics
29
what are the three ways that a bacteria will move without using a flagella?
1.) twitching - short, jerky movement (cells are in contact with each other and surface) 2.) gliding - smooth movement w/o appendage and slime can help with movement 3.) spirochete motility - flagella is on the inside and windling around cell (flexing and spinning movement)
30
what is a survival stratgey made by a bacteria?
- using endospores in response to nutrient depletion - which are resistant to envionrmnetal changes
31
how does archaea cell envelope differ from bacteria?
- some lack cell walls - The slime layer is used to mediate cell-to-cell interactions - s-layer is standard used
32
The common shape of archaea?
-cocci and rod shape
33
what does an archaea membrane look like?
- unique lipids - that are branched chains of hydrocarbons attached to a glycerol by ether linkage
34
what is the difference between archea and bacterias cytoplasm?
- A ribosomes have different nuc sequences so which means the protein composition is different (makes them unaffected by antibiotics attacking ribosomes) - more similar to Euk
35
what are the two types of pilli? archaea
- cannulae - hollow tube structure (how daughter cells are connected to each other) - hami - looks like a grappling hook (biofilm)
36
three characteristics of Archaea flagella?
- thinner than bacteria - not hollow - powered by ATP hydrolysis - direction moves the cell forward or backward
37
what is EUK plasma membrane made up of?
sphingolipids sterols phospholipids (hydrophobic fatty acids)
38
Two types of euk? charachteristics?
- protist and fungi - common in ecosystems - adapts - larger than A and B - major human pathogen
39
EUK cytoskeleton (3 types of filaments)
- helps organize cytoplasm - cell shape/motor proteins associated with filaments that guide cell movements 1. actin - small (helps shape) 2. microtubules - thin (spindles) 3. intermediate - flexible and structural
40
EUK flagella and cillia
- long whiplike and move in an undulating fashion - short hair-like structures and beat with 2 phases
41
viron? nucleocapsid
- mature virus particles - composed of nucleic acid (DNA or RNA) and a protein coat (capsid)
42
2 broad types of virus?
1. non-evloped (naked) 2. enveloped - has a lipid membrane
43
viral envelope?
- a flexible membraneous layer of lipids and carbs - can have spikes or peplomers on their surface - can be used to identify a virus
44
what are the five steps of viral multiplcation?
1.) attachment 2.) entry 3.) synthesis 4.) assembly 5.) viron release
45
how does a virus attach and enter?
- ligand attaches to host cell receptor (determines host prefrence) - virus genome enters
46
three methods used to release DNA?
- fusion of biral envelope with host cells plasma membrane - endocytosis - release of nucleic acid
47
what are the two ways virons can be released?
- host cell lysis (non-enveloped) - relase by budding (enveloped)
48
virulent phage vs temperate phage
- v - has one reproductive choice (multiplies upon entering and released from host by lyses) - T - two reproductive options (reproduces lytically like virulent and will remain in host cell without destroying it)
49
lysogeny
- relationship between temperate phage and host - prophage form of the virus that remains within host until unfavorable conditions and will convert into lytic where it will burst out of cell
50
how can viruses by cultivated?
- viruses can not be cultured - plaque-forming units (lytic cycle)
51
one step growth curves
1.) inoculation - virus binds (decrease) 2.) Eclipse - virion penetrates cells (plateau) 3.) Burst - host cell releases many viral particles (increase) 4.) Burst size - number of virions released per bacterium (plateau)

microbio (5 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions