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Microbiology > Cell biology > Flashcards

Cell biology Flashcards

1
Q

Eukaryotes

A

Eu means true and Karyon means nucleus
DNA is contained wihtin a membrane bound nucleus
- arranged as multiple chromosomes

Organelles are present and membrane-bound

Can be either single celled or multicellular
- most eukaryotes are multicellular

Includes protists (no longer considered a group of eukaryotes, easier to fit them into smaller groups), fungi, plants and animals

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2
Q

What do eukaryotes include?

A

Fungi, Plants and animals

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3
Q

DNA of Eukaryotes

A

Dna is contained iwthin a membrane bound nucleus
- arranged as multiple chromosomes

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4
Q

Organelles of eukaryotes

A

Present and membrane bound

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5
Q

Are eukaryotes multicellular or unicellular

A

Can be either unicellular or mutlicellular, but most euk. are mutlicellular

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6
Q

Prokaryotes

A

Pro means before, karyon means nucleus
- DNA is not enclosed within a membrane
- chromosome is single and circular and exists within a specific region of the cell called the nucleoid

They do not have membrane bound organelles such as mitochondria

Single celled organisms only
- bacteria and archaea

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7
Q

Prokaryotes include

A

Bacteria and archaea

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8
Q

DNA of prokaryotes

A

DNA is not encolsed within a membrane
- chromosomes are single and circular - exist in a specific region of the called called the nucleoid

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9
Q

What do prokaryotes lack that eukaryotes have?

A

Prokaryotes do not have membrane bound organelles such as mitochondria and the DNA isn’t membrane bound, so prokaryotes DNA is in a region called the nucleoid
- they are also single celled only! (includes bacteria and archaea

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10
Q

Morphology means…?
- what are the different morphologies

A

means shape

Shapes: Bacillus, coccus (diplococci, streptococci and staphylococci), and spirillum (spirochete and spirilla)

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11
Q

What are are the different bacterial morphologies and their examples

A
  1. Coccus: spherical
    - Diplococci - 2 cocci
    - Staphylococci - looks like grape
    - Streptococcus - coccus arranged in chains
    ex. Streptococcus pyogenes
  2. Bacillus: rods
    ex.Escherichia coli aka E.coli
  3. Spirillum: Spiral
    - Spirochete: long, flexible
    ex. Treponema pallidum
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12
Q

Streptococcus pyogenes shape

A

Streptococcus (a cocci shape)

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13
Q

Coccus and the different cocci, provide an example

A

Spherical
- Diplococci
- Staphylococcus
- Streptococcus

ex. Streptococcus pyogenes or Streptococcus mutans (capsulated and in our teeth)

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14
Q

Escherichia coli shape

A

Bacillus (rods)

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15
Q

Bacillus

A

Rods
ex. Escherichia coli

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16
Q

Treponema pallidum shape

A

Spirillum

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17
Q

Spirillum

A

Spiral
- Spirochete: long, flexible
- Hellical shaped organism: typically short, rigid, not a lot of flexibility

ex. Treponema pallidum

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18
Q

Name the outermost layer of bacterium

A

Glycocalyx (sugar coat)

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19
Q

Glycocalyx

A

Sugar coat
- gelatinous, sticky polymer (if sticky better chance to stick to surface)
- Can be composed of either polysaccaride, protein or both
- when its made of only sugar, its called an extracellular polysaccaride

  • Secreted from the prokaryote onto the outside of the cell wall

Arrangement could be different so there’s two different kinds, can be either a capsule or slime layer

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20
Q

When the glycocalyx is only a sugar then what is it?

A

An extracellular polysaccaride

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21
Q

What are the two different kinds of glycocalyx

A

The way they’re going to be arranged is going to be different
1. Capsule: when the substance of the glycocalyx is firmly attached to the cell wall and organized (organized sugar layer - tight on surface)
2. Slime layer: when the substance of the glycocalyx is disorganized and only loosely attached to the cell wall

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22
Q

Capsule

A

when the substance of the glycocalyx is firmly attached to the cell wall and organized (organized sugar layer - tight on the surface)

Capsules contribute to an organisms virulence
- does so by protecting the organism from phagocytosis (= important for immune defense)

  • Certain organisms such as Bacillus anthracis can only cause disease if they are encapsulated

The capsule also allows the organism to adhere to and colonize host cells (eating a lot, replicating a lot, producing a lot of acids when metabolizing)

Also protects the bacterial cell against dehydration and holds nutrients inside the cell

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23
Q

explain virulence and capsules

A

is the ability to cause disease
- the capsule of an organism contributes to their virulence b/c the bacteria can adhere and colonize host cells

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24
Q

Streptococcus mutans are an example of

A

encapsulated organisms
- Streptococcus mutans attaches to teeth and may cause cavities
- some organisms such as Streptococcus mutans may use their capsule as an energy source, breaking down the sugars when energy sources are low (use the stuff left on your teeth/mouth as nutrients)

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25
Q

Bacillus anthracis

A

can only cause disease if they are encapsulated (capsules as an external structure)

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26
Q

Slime layer

A

when the substance of the glycocalyx is disorganized and only loosely attached to the cell wall

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27
Q
  • Describe Flagella of prokaryotes
  • name the parts of flagella
  • name the different flagellar arrangements
  • What are flagellar proteins and their purpose?
  • The types of flagellar movement and what it depends on
A

found on some prokaryotic cells
- long, filamentous, used for motility

Composed of three primary parts
1. filament
2. hook
3. basal body

Flagellar arrangements
1. peritrichous
2. monotrichous
3. lophotrichous
4. amphitrichous

Flagellar proteins are used to differentiate between strains of different bacteria
- Example:* E.coli* 0157:H7 (0157 = the strain thats found on cows and the H7 is the type of flagellar protein)

Flagella can rotate either clockwise or counterclockwise
- run/swim and tumble
- Taxis: chemotaxis and phototaxis
- This flagellar movement depends on energy production

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28
Q

3 primary parts of flagella

A

1. Filament: composed of the circular flagellin
protein (lots) forming a helix around a hollow core
- Is not covered by a sheath

2. Hook: (= flexibility) made of different protein than the flagella (diff protein, diff location, diff function)

3. Basal body: anchors the flagellum (fasten and attached to a more stabilized structure)

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29
Q

Filament

A

A primary part of flagella (an external structure)
Filament: composed of the circular flagellin
protein forming a helix around a hollow core
* Is not covered by a sheath

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30
Q

Hook

A

A primary part of flagella (an external structure)
made of different protein than the flagella (diff protein, diff function, diff location)

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31
Q

Basal body

A

A primary part of flagella (an external structure)
anchors the flagellum to the plasma
membrane and the cell wall

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32
Q

name the different Flagellar arrangements

A
  1. Peritrichous: flagella distributed over the entire cell surface
  2. Monotrichous: single polar flagella
  3. Lophotrichous: two or more flagella at one or both ends of the cell
  4. Amphitrichous: a tuft of flagella at each cell end
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33
Q

Peritrichous

A

A type of flagellar arrangement
- flagella distributed over the entire cell surface

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34
Q

Monotrichous

A

A type of flagellar arrangement
- single polar flagella

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35
Q

Lophotrichous

A

A type of flagellar arrangement
- two or more flagella at one or both ends of the cell

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36
Q

Amphitrichous

A

A type of flagellar arrangement
a tuft of flagella at each cell end

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37
Q

Flagellar proteins

A

are used to differentiate in ebtween strains of different bacteria

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38
Q

E.coli 0157:H7

A

0157 = strain thats found in cows
H7 = type of flagellar protein (= differentiate diff strains of diff bacteria)

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39
Q

Explain bacterial motility
- explain run or swim
- explain tumbles
Explain the different types of taxis

A

The bacterium is able to change direction and speed on its own
- Run or Swim: movement in one direction for a continuous period of time
- Tumbles: Abrupt or random changes in direction
- results when the flagellum changes its direction of rotation (like a car using a wheel)

Being motile allows the bacterium to move away from dangerous enviornments and toward favorable enviornments which is called taxis
types
1. Chemotaxis
2. phototaxis

Bacteria move toward an attractant and away from a repellant

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40
Q

Run (or swim)

A

Movement in one direction for a continuous period of time

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41
Q

tumbles

A

Abrupt or random changes in
direction
- Results when the flagellum changes its
direction of rotation

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42
Q

taxis

A

Bacterial motility
Being motile allows the bacterium to
move away from dangerous environments
and toward favorable environments

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43
Q

Chemotaxis

A

Movement toward a chemical stimulus

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44
Q

Phototaxis

A

Movement toward a light stimulus

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45
Q

Pili and Fimbriae are found in? Compare them to flagella and what do both contain?

A

many gram negative bacteria (used for attachment and made from protein)

Both are:
- hair like appendages that are shorter, thinner and straighter than flagella and are not used for motility
- made of pilin protein

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46
Q

Define Fimbriae
- where can fimbriae be found on the bacteria
- the importance of fimbriae
- provide an example

A

Found in many gram - cells, and is made of the same pilin protein and the pili
- bacterial cell can contain a few or hundreds

can be all over cell surface or only at poles

Enables the bacterial cell to adhere to surfaces and other bacterial cells (so that they dont get washed away)
- Allow the bacterium to adhere and colonize without fimbriae colonization cannot occur and thus disease does not occur
- ex. Neisseria gonorrhoeae

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47
Q

Neisseria gonorrhoeae is an example of

A

A bacterial cell that has fimbriae on its surface

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48
Q

What is Pili and the importance of pili?

A

(pilus-singular)
Longer than fimbriae (made from same pilin protein, not used to specifically stick to anythings- specialized for exchange, “photocopy” info)
- only one or two per cell

these filaments join two bacterial cells in order to transfer DNA in between them in a process called conjugation (horizontal gene transfer)

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49
Q

What is Conjugation and what does it involve
Provide an example

A

is the process for exchange,
- involves Pili filaments which join two bacterial cells in order to transfer DNA in between them is a process called conjugation
- ex. for antibiotic resistance genes

50
Q

What are pili and fimbriae made of?

A

pilin protein

51
Q

Pilin protein makes up

A

pili nd fimbriae (found in many gram negative bacteria)

52
Q

What is the Bacterial cell wall
- its composition and structure
- the importance of the cell wall for bacteria

A

is the “outer layer”- most commmon to most bugs
- composed of the polysaccaride peptidoglycan
- semi rigid, complex and semi-permable

provides the cell with its characteristic shape (ex. coccus = certain cell wall)
- Important means of classifying bacteria

protect cell from environmental changes
- prevents cell rupture (like a counter pressure against expansion and rupture ex. like a balloon in a cup)

53
Q

(prokaryotic) Bacterial cell wall shape

A

semi-rigid, complex and semi-permeable
- the bacterial cell wall provides the cell with its characteristic shape (ex. the way you arrange it is based on the outer walls the shape ex. coccus = certain cell wall)

54
Q

Importance of the bacterial cell wall

A

It protects the cell from environmental changes
- prevents cell rupture

provides cell w/ its characteristic shape
- important means of classifying bacteria, provides cells with its characteristic shape
- ex. e. coli is always going to have the same cell wall structure

55
Q

What is the bacterial cell wall composed of

A

polysaccaride peptidoglycan (made of sugar)

56
Q

Peptidoglycan is

A

polysaccaride composed of repeating dissacarides (=NAG and NAM)

57
Q

Structure of peptidoglycan and importance of this structure

A

Peptidoglycan = polysaccaride = repeating dissacarides (NAM and NAG)

Polysaccaride chains are layered on top of one another
- chains are linked together by short polypeptides = creating a lattice
- creates a strong cell wall that is resistance to osmotic changes

58
Q

Explain how polysaccarides form peptidoglycan and why polysaccarides are important to the cell wall

A

Polysaccaride (carbohydrate) makes up peptidoglycan (makes up bacterial cell wall)
- polysaccaride chains are layered on top of one another
- the chains are linked together by short polypeptides (proteins/aminoacids) = lattice

The lattice creates a strong cell wall that is resistant to osmotic changes

59
Q

The dissacaride unit of (polysaccaride) pepitdoglycan is composed of

A
  • N-acetyl glucosamine (NAG)
  • N-acetyl muramic acid (NAM)
60
Q

NAG and NAM

A

are the dissacaride unit in the polyssaccarides of peptidoglycan (bacterial cell wall)
- they create a lattice in peptidoglycan w/ short polypeptide chains = lattice
- this lattice helps prevent osmotic changes in the cell

61
Q

Explain the structure of the gram positive cell wall and how is it different from a gram negative cell wall?

what gram positive cell organisms only have that gram negative dont?

A

Contains a thick layer of peptidoglycan (lots of chains of nam and nag) outside of the plasma membrane
- also contains teichoic acids which are only found in gram positive organisms (wall teichoic acids and lipoteichoic acids)

Gram positive bacteria have only one membrane: the plasma membrane

62
Q

Explain Teichoic acids and what are the different forms

A

teichoic acids are only found in gram positive organisms
two forms:
1. wall teichoic acids (perpendicular thru all layers of peptidoglycan): extend out from peptidoglycan
2. lipoteichoic acids (to make the cell membrane structurally intact): connect the plasma membrane to the peptidoglycan

63
Q

Wall teichoic acids

A

A form of teichoic acids:
- extend out from the peptidoglycan (perpendicular through all layers of peptidogly can) in a gram + cell wall

64
Q

Lipoteichoic acids

A

A form of teichoic acids:
- connect the plasma membrane to the peptidoglycan (make the cell membrane structurally intact) of the gram + cell wall

65
Q

Explain the structure of the Gram Negative Cell Wall

How is it different from the gram + cell wall

A

Thin peptidoglycan layer (thick in gram +)
- gram negative bacteria contain a plasma membrane and an outer membrane (more space compared to gram +, 2nd lipid membrane on top of peptidoglycan)
(gram positive only has one plasma membrane)

The outermembrane contains (while the gram positive contains only teichoic acids)
1. lipids
2. proteins
3. lipolysaccarides (LPS)

66
Q

What does the outermembrane of the Gram negative cell wall contain?

A

Lipids (phospholipids)
proteins
Lipopolysaccharides (LPS)

67
Q

Lipolysaccarides

A

Make up the outer membrane of Gram Negative Cell walls only (lipid sugar)

1. Lipid Portion
- toxic
- referred to as endotoxin (lipid A)

2. Polysaccaride portion (sugar is sticking out)
- composed of O sugars
- used to distinguish gram negative organisms

68
Q

Lipid portion of Lipopolysaccarides

A

A part of gram negative outer membranes (the 2nd lipid membrane on topp of peptidoglycan)
Lipid portion is:
- toxic
- referred to as endotoxin (lipid A)

69
Q

Polysaccaride portion of Lipopolysaccarides

A

A part of gram negative outer membranes (the 2nd lipid membrane on topp of peptidoglycan)
Polysaccaride portion:
- Composed of O sugars (sugars are sticking out)
- used to distinguish gram negative organisms

70
Q

What is the purpose of the Gram Stain

A

Staining technique wants to know which is gram + or gram - for diagnostics for antibiotics

71
Q

Compare the primary stain of Gram + and - cells

A

Primary stain:
- Gram-positive cells = thick peptidoglycan holds the primary stains w crystal violet (purple) - positively charges sticks to any living cell (= negative charged)
- Gram-negative cells = not stained with crystal violet because the alcohol wash step disrupts the plasma membrane and also the outer membrane is intact and not penetrated by the dye (due to the double membrane) however, retains the counter stain = safranin stain (appear pink

72
Q

The primary stain on Gram positive cells

A

First step of the gram stain:
contain thick peptidoglycan which holds the
primary stain with crystal violet (appearing purple)
- positively charges sticks to any living cell (= negative charged

73
Q

The primary stain on Gram negative cells

A

First step of the gram stain:
are not stained with crystal violet (compared to gram positive cells= stained) because the outer membrane is intact and is not penetrated by the dye (due to the double membrane)

74
Q

Explain the steps of the gram stain

A

First step:
- Gram positive cells: contain thick peptidoglycan which holds the primary stain with crystal violet (appearing purple)

- Gram negative cells: are stained crystal violet but dont retain after the 3rd step = alcohol wash because the outer membrane is intact and is not penetrated by the dye

second step:
add iodine (creates a stain thats more vigorous)

third step:
involves an alcohol wash which disrupts the outer membrane and washes away remaining crystal violet on the gram negative

The last step:
adds safranin (counterstain) which is taken up by the peptidoglycan in gram negative cells which consequently appear pink

75
Q

Whats Iodine’s purpose in stains

A

add iodine (mordant) which creates a stain thats more vigorous

76
Q

Alcohol wash

A

The third step of the gram stain disrupts the outer membrane and washes away remaining crystal violet

77
Q

safranin (counterstain)

A

The gram stain’s last step adds safranin taken up by the peptidoglycan in gram negative cells which consequently appear pink

78
Q
  • Peptidoglycan in prokaryotes vs. eukaryotes
  • Explain lysozyme and penicillin in regards to peptidoglycan
A

peptidoglycan is unique to bacteria
- eukaryotes do not have a similar compound

Peptidoglycan is a common target for both host defenses and chemotherapies

  • Lysozyme is a host enzyme produced in saliva, tears and mucous which degrades peptidoglycan
  • Many antibiotics are also active against peptidoglycan including Penicillin which targets peptidoglycan synthesis
79
Q

What type of host defenses target peptidoglycan

A

lysozyme and penicillin

80
Q

Lysozyme and peptidolgycan

A

Is a host enzyme produced in saliva, tears and mucous which degrades peptidoglycan
- if you didnt have lysozyme, this causes bacterial build up

81
Q

Pencillin and peptidoglycan

A

penicilin (= antibiotic can do harm if the person has an allergy to penicillin) targets peptidoglycan synthesis (go around and destroy the cell wall of the bacteria)

82
Q

What is the Plasma membrane composed of

A

Classic phospholipid bilayer, provides a barrier in between the intracellular and extracellular enviornments

83
Q

Semi-permeable barrier and semi-fluid state

A

Prokaryotic Cell membrane
The plasma membrane is a semi-permeable barrier,
Semi-permeable barrier = selectively allows the inflow and outflow of materials

The plasma membrane also exists in a semi-fluid state
- fluid enough that membrane proteins are able to move and perform their function
- solid enough to maintain cell shape (adjust fluidity according to the environment (ex. temp) - saturated or unsaturated lipids

84
Q

what disrupts the plasma membrane

A

alcohold disrupts the plasma membrane

85
Q

What is the name of the fluid that is contained within the plasma membrane

A

Cytoplasm

86
Q

The Cytoplasm in prokaryotic cells

A

The material thats contained within the plasma membrane

~80% water

Cytoplasm also contains many of the materials needed for life:
• Amino acids, carbohydrates, nucleotides
• Enzymes
• Inorganic ions (ex) iron

Cytoplasm is aqueous but thick and semi-transparent

Cytoplasm also contains the major cellular structures such as
- the nucleoid
- Ribosomes
- inclusion bodies
- some bacteria may also have endospores within the cytoplasm

87
Q

What is Cytoplasm composed of and what is contained within the cytoplasm of prokaryotic cells

A

~80% water (75-80% norm cell water content)
Cytoplasm also contains many of the materials needed for life:
- amino acids, carbohydrates, nucleotides, enzymes
- inorganic ions (ex iron)

Cytoplasm also contains the major cellular structures such as:
* the nucleoid: containing the cell’s genetic material
* Ribosomes (protein synthesis)
* inclusion bodies
* Some bacteria may also have endospores within the cytoplasm

88
Q

Major cellular structures in the cytoplasm of prokaryotes

A
  1. The nucleoid
  2. Ribosomes (protein synthesis)
  3. inclusion bodies
  4. some bacteria may also have endospores within the cytoplasm (allow them the opportunity to survive compelx enviornments like temp.)
89
Q

What is a nucleoid

A

It is a part of prokaryotes

  • they contain the bacterial chromosome (just one chromosome): contains all genetic information required for the cell structure and function
  • NOT surrounded by a nuclear membrane = It is a nuclear area of the bacterium (because its non-membrane bound)
  • Bacteria may also have plasmids
90
Q

What are Plasmids and give an example for their function

A

Bacteria (a prokaryote) may also have plasmids (small)
- small, usually circular double stranded DNA molecules (if the bug booted out a plasmid, it would be fine, just needs the chromosome)
- These house non-essential genes which can help the bacterium to survive adverse conditions such as high antibiotic concentrations
ex) plasmids contain genes for antibiotic resistance

91
Q

Function of Ribosomes
what are they made of?

A

Protein synthesis occurs in ribosomes

They are made of protein and ribosomals RNA (rRNA)
Consist of two subunits, a large subunit and a small subunit

92
Q

What are ribosomes made of?

A

Protein, ribosomal RNA (rRNA)
and two subunits: large and small

93
Q

What do ribosomes consist of?

A

two subunits, a large subunit and a small subunit

94
Q

Large subunit

Compare prokaryote and eukaryote whole ribosome

A

= Large subunit

Prokaryotes = 50s (large) + 30s (small) = 70s (whole ribosome)
Eukaryotes = 60s (large) + 40s (small) = 80s (whole ribosome)
Prokaryotes are smaller

95
Q

Small subunit

Compare prokaryote and eukaryote whole ribosome

A

= small subunit

prokaryotes = 30s (small) +50s (large) = 70s (whole ribosome)
Eukaryotes = 40s (small) + 60s (large) = 80s (whole ribosome)

96
Q

Compare ribosomes of prokaryotes and eukaryotes

A

Ribosomes of prokaryotes are different than those of eukaryotes
- the both fucntion in protein synthesis
- Eukaryote ribosomes are larger and heavier (80s): the large subunit is 60S and the small subunit is 40S

97
Q

Why do several antibiotics target bacteria ribosomes

Also provide examples of antibiotics that target ribosomes

A

Several antibiotics target bacterial ribosomes because it is the perfect opportunity to execute selective toxicity (paul elnrich and syphillis)
- eukaryotic ribosomes are different and thus an antibiotic that targets ribosomes will not cause harm to host cells

ex. Streptomycin and Erythromycin

98
Q

Streptomycin and Erythromycin are examples of

A

antibiotics that target ribosomes but will not cause harm to host cells selective toxicity!
- eukaryotic ribosomes are different!

99
Q

What are Inclusion bodies and their function?

Name the types as well

A

are deposites of nutrient granules which are stored for later use
- different bacterial species contain a variety of inclusion bodies which can therefore serve as a basis for indentification (Can also determine if its gram + or - other than gram stain)

Types of inclusion bodies:
* Sulfur granules (like a bubble and in that bubble - source of sulfur, some bacteria use it for energy
IMPORTANT energy sources
* Polysaccaride granules (nrg storage form)
* Lipid inclusions (like fuel)
* Enzymes (speed up rxns)

100
Q

Types of inclusion bodies

A
  • Sulfur granules (like a bubble and in that bubble - source of sulfur, some bacteria use it for energy
    IMPORTANT energy sources
  • Polysaccaride granules (nrg storage form)
  • Lipid inclusions (like fuel)
  • Enzymes (speed up rxns)
101
Q

Endospores and their characteristics

provide examples of endospores too

A

Only gram positive bacteria form endospores
- these are special structures that allow the bacterium to resist heat, desication, chemicals and radiation
- the bacterium will remain dormant for long periods of time and will leave dormancy only when good growth conditions occur
- spores are very resilient and some can even survive boiling water for hours making them very difficult to get rid of

ex. of spore forming bacteria include:
- Baccillus anthracis (has endospores and capsules)
- Clostridium botulinum

102
Q

Why are endospores hard to get rid of?

A

endospores are special structures that allow the bacterium to resist heat, dessication, chemicals and radiation
- endospores are very resilient and some can survive boiling water for hours = difficultto get rid of them

103
Q

example of spore forming bacteria

A
  • Baccillus anthracis
  • Clostridium botulinum
104
Q

Baccillus anthracis
andClostridium botulinum
are examples of

A

Spore forming bacteria (endospore)

105
Q

Explain the Sporulation steps

A

How endospores form

  1. Bacterial cell replicates its DNA
  2. Septum forms dividing the cell
  3. The larger compartment engulfs the smaller one forming a forspore within the mother cell
  4. Peptidoglycan and other protective material forms around the forspore (the spore coat)
  5. The spore is freed from the mother cell
106
Q

Eukaryotic cells can be

A

both unicellular organisms and multicellular organisms

These cells are larger and more complex than prokaryotes

107
Q

Simple eukaryotes include

A

Protozoa: unicellular
Fungi: multicellular except yeast (individual cells)
Algae: some are unicellular and some are multicellular

108
Q

Higher eukaryotes include

A

plants and animals (no unicellular)

109
Q

Eukaryotic flagella and cilia

Compare and Contrast to Prok. Flagella and Cilia

A
  • These are long and flexible
  • they also contain protein and cytoplasm (prokaryotes have hollow flagella and cilia)
  • These move in a whip-like fashion (prokaryotes move in a cork screw motion)
  • Both cilia and flagella are used for motility
110
Q

Euk. Cell wall

A

not present in animal cells
- Structurally simple compared to peptidoglycan of bacteria
- composed of a single polysaccaride:
- cellulose: algae and plants
- chitin: fungi

111
Q

Cellulose

A

Euk. cell wall is composed of a single polysaccaride
- in algae and plants

112
Q

Chitin

A

eukaryotic cell wall of fungi (=euk. cell wall is composed of a single polysaccharide)

113
Q

Euk plasma membrane

compare and contrast w/ prok. cells

A

same basic structure as prokaryotic cells
- contain phospholipids, proteins and sterols
- Prokaryotes do not have sterols in their plasma membrane, as a result the eukaryotic plasma membrane is more rigid than that of bacteria

  • Eukaryotes are often capable of endocytosis (engulf particles outside of the cell and bring them inside)
114
Q

Endocytosis

A

Eukaryotes are often capable of endocytosis = engulf particles outside of the cell and bring them inside

115
Q

Euk. Cytoplasm

A

Similar in prokaryotes but there are differences
- this is located within the boundary of plasma membrane, but outside the nuclear membrane

The cytoplasm has a complex internal structure called a cytoskeleton which:
- provide support + shape to the cell
- act to transport substances through the cell
- composed of protein filaments on the inside of the plasma membrane

116
Q

Cytoskeleton

what is it and what is it composed of

A
  • provide support + shape to the cell
  • act to transport substances through cell
  • composed of protein filaments on the inside of the plasma membrane
117
Q

Membrane bound organelles

A

are structures that are absent in bacteria
- Structures w/ specialized functions

Examples of membrane bound organelles
- Nucleus: contains genetic material
- Mitochondria: powerhouse of cell, site of ATP synthesis
- Chloroplasts: site of photosynthesis, found in plants and algae only

118
Q

Nucleus

A

Membrane bound organelle (absent in baxcteria)
- contains genetic material

119
Q

Mitochondria

A

Membrane bound organelle
- powerhouse of the cell,
site of ATP synthesis

120
Q

Chloroplasts

What is it and what organisms is it found in

A

Membrane bound organelle
- site of photosynthesis,
found in plants and algae only

Microbiology (6 decks)

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