Lecture3 Peptidoglycan synthesis and Eukaryotic Cell structure Flashcards

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1
Q

Gram-postive bacteria stain ____

A

purple

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2
Q

Gam-negative bacteria stain ____

A

pink

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3
Q

Giemsa staining is due to

A

cell wall structure

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4
Q

What two alternating sugars for peptidoglycan backbone

A
  • N-acetylglucosamine (NAG)

- N-acetylmuramic acid (NAM)

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5
Q

Peptidoglycan chains have alternating ___ and ____ amino acids attached to ____

A

D-, L-, attached to NAM

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6
Q

Peptidoglycan is joined by crosslinks between the _____

A

peptides

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7
Q

E. coli peptidoglycan exhibits _____ cross-linking

A

direct

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8
Q

Staphylococcus aureus peptidoglycan exhibits _______ linking

A

Peptide interbridge

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9
Q

Peptidoglycan synthesis is a complex process involving _____ derivatives

A

UDP

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10
Q

Peptidoglycan synthesis uses ____ to transport NAG-NAM- pentapeptide units across the cell membrane

A

bactoprenol

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11
Q

Function of Bacitracin

A

Does not allow bactroprenol carrier to lose one phosphate (bactoprenol phosphate) and move back to the cytoplasmic side of the membrane

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12
Q

The final step in peptidoglycan synthesis is _____which creates the peptide cross-links between the peptidoglycan chains

A

transpeptidation

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13
Q

Amino acids are added to NAM one at a time, except for the last _____ ____, which are added in the same reaction

A

D-alanines

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14
Q

What are the two carriers involved in peptidoglycan biosynthesis

A
  • Bactoprenol

- Uridine diphosphate

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15
Q

A 55-carbon alcohol that attaches to NAM by a pyrophosphate group and moves peptidoglycan units through membrane

A

Bactoprenol

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16
Q

Bactoprenol is a ___- carbon alcohol that attaches to NAM by a _____ group

A

55, pyrophosphate group

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17
Q

Bactoprenol function

A

moves peptidoglycan units through hydrophobic membrane

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18
Q

Uridine diphosphate is an activated ______ carrier, except in the case of peptidoglycan synthesis it carries _____ or ____ instead of glucose

A

sugar, NAM or NAG

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19
Q

Cycloserine inhibits

A

Blocks formation of D-Ala-D-Ala

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20
Q

______ inhibits transpeptidation by binding to D-Ala-D-Ala

A

Vancomycin

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21
Q

Penicillin inhibits the ______ reaction

A

transpeptidation

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22
Q

_____ blocks the dephosphorylation of bactoprenol pyrophosphate

A

Bacitracin

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23
Q

The 8 stages of peptidoglycan synthesis

A
  • UDP derivatives of NAM and NAG are synthesized in the cytoplasm
  • Amino Acids are added sequentially to UDP-NAM to form the pentapeptide chain
    - The 2 terminal D-alanines are added as a dipeptide
    - No ribosomes involved
  • NAM-Pentapeptide is transferred from UDP to a bactoprenol phosphate at the membrane surface
  • UDP-NAG adds NAG to the NAM-pentapeptide
    - Glycine interbridge, if present, is added
  • The completed unit is transported across the membrane to its outer surface by the bactoprenol pyrophosphate carrier
  • The peptidoglycan unit is attached to the growing end of a peptidoglycan chain
  • Bactoprenol returns to inside of membrane. A phosphate is released; bactoprenol phosphate can now accept another NAM-pentapeptide
  • Transpeptidation occurs
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24
Q

How does a bacterial cell add new peptidoglycan units to its existing cell wall

A
  • Autolysis carry out limited digestion of peptidoglycan

- This provides acceptor ends for addition of new peptidoglycan units

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25
Q

are ribosomes involved in the amino acids being added sequentially to UDP-NAm to form the pentapeptide chain

A

No!

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26
Q

Gram-positive bacteria stain

A

purple

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27
Q

Gram-negative bacteria stain

A

pink

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28
Q

The gram staining reaction is due to

A

cell wall structure

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29
Q

Inventor of gram stain

A

Danish physician Hans christian Gram

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30
Q

The gram stain was invented in ____ and published in

A

1883 and published in 1884

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31
Q

Hans Christian Gram studied ____ tissue sections form patients who died of ____

A

lung, pneumonia

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32
Q

Han Christian Gram discovered that _____ and a solution of ___ and ____ formed a water soluble precipitate that could be removed from host tissues and some microbial cells by an alcohol rinse. Many other microbes retained the stain

A

Gentian (crystal) violet, iodine, and potassium iodide

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33
Q

Hans Cristian Gram did not originally use ____ in his stain

A

safranin

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34
Q

Gram stain primary stain is _____ in combination with ___.

A
  • Crystal violet in combination with iodine
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35
Q

What is the function of iodine in the gram stain

A

it acts as a mordant to enhance crystal violet staining

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36
Q

What is the counter stain used in gram staining

A

Safranin

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37
Q

What is used to decolorize the gram negative bacteria

A

Alcohol or acetone removes crystal violet from Gram-negative cells

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38
Q

Gram-positive cell wall has a ___ ring basal body

A

2

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39
Q

Gram-negative cell wall has a ___ ring basal body

A

4

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40
Q

Gram-positive cell wall is disrupted by ____ and sensitive to ____

A

lysozyme, Penicillin

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41
Q

Gram-negative cell wall is _____ sensitive

A

Tetracycline (because it attacks the ribosomes)

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42
Q

Acid-fast cells resist decolorization with _____

A

acid alcohol

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43
Q

the basis for acid-fast staining is a ____ cell wall composed of ______

A

waxy cell wall composed of mycolic acids

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44
Q

examples of cells that stain with acid-fast stain

A
  • Mycobacterium

- Nocardia

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45
Q

The waxy cell wall composed of mycelia acids prevents

A

water-soluble stains form crossing the cell wall

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46
Q

Acid-fast staining methods use ______, which is a ______ soluble stain

A

carbolfuchsin, lipid soluble stain

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47
Q

Acid-fast stain ,Carbolfuchsin, contains ____ to help the stain penetrate the cell wall

A

Phenol

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48
Q

Acid-fast cells often give ____ gram stain results, this is due to

A

abnormal, poor stain absorption followed by high retention

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49
Q

Acid fast staining is important for identifying bacteria in the genus _____, which can be pathogenic

A

Mycobacterium

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50
Q

Examples of bacteria in the genus Mycobacterium

A
  • M. leprae
    • leprosy
  • M. tuberculosis
    • Tuberculosis
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51
Q

Acid fast staining can be used to identify opportunistic pathogenic members of the actinomycete genus _____ and oocysts of coccidian parasites, such as _______ and _____

A

Norcardia, Cryptosporidium, Isospora

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52
Q

bacterial spores are _____, as well as the head of sperm, and certain eukaryotic cellular inclusions (neuronal cytoplasmic inclusion bodies and nuclear inclusion bodies)

A

acid fast

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53
Q

What is a common counterstain in acid fast staining

A

methylene blue

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54
Q

Carbolfuchsin stains what color

A

Red

55
Q

Mycoplasmas lack

A

cell walls

56
Q

Mycoplasmas have what in their plasma membranes

A

sterols

57
Q

the cell walls of archaea can be ____ or ____

A

absent or pseudomurein (lack NAM and D-amino acids)

58
Q

What two groups of eukaryotes commonly possess microbial members

A
  • protists

- fungi

59
Q

Prominent members of ecosystem, useful as model systems and industry, and some are major human pathogens

A

Eukaryotic microorgansims

60
Q

What are the common features of Eukaryotic cells

A
  • Membrane-delimited nuclei
  • Membrane-bound organelles that perform specific functions
  • Intracytoplasmic membrane complex serves as transport system
  • More structurally complex and generally larger than bacterial or archaeal cells
61
Q

The intracytoplasmic membrane complex serves as ____ system in eukaryotic cells

A

transport

62
Q

Functions of plasma membrane in eukaryotic cells

A
  • mechanical cell boundary
  • selectively permeable barrier with transport system
  • mediates cell-cell interactions and adhesion to surfaces
  • secretion
  • signal transduction
63
Q

Functions of cytoplasm

A
  • Composed of cytosol (liquid portion) and organelles

- location of many metabolic processes

64
Q

Functions of Cytoskeleton

A
  • Composed of actin filaments, intermediate filaments, and microtubules
  • provides cell structures and movements
65
Q

Functions of endoplasmic reticulum

A
  • Transport of materials

- lipid synthesis

66
Q

Functions of ribosomes

A

Protein synthesis

67
Q

Function of golgi apparatus

A
  • Packaging and secretion of materials for various purposes

- lysosome formation

68
Q

Function of Mitochondria

A
  • Energy production through use of the tricarboxylic acid cycle, electron transport, oxidative phosphorylation, and other pathways
69
Q

Function of Chloroplasts

A
  • Photosynthesis (trapping light energy and forming carbohydrate from CO2 and water)
70
Q

Functions of nucleus

A

repository for genetic information

71
Q

Functions of Nucleolus

A
  • Ribosomal RNA synthesis

- Ribosome construction

72
Q

Functions of Cell wall and pellicle

A
  • Strengthen and give shape to the cell
73
Q

Functions of cilia and flagella

A
  • cell movement
74
Q

Functions of vacuole

A
  • Temporary storage and transport
  • Digestion (food vacuoles)
  • Water balance (contractile vacuole)
75
Q

Where are free ribosomes located

A

-cytosol, nucleus, and mitochondria

76
Q

Where are bound ribosomes located

A

on the Rough ER

77
Q

Eukaryotic cell envelopes consist of the _____ and ____

A

plasma membrane and all coverings external to it

78
Q

The plasma membrane of eukaryotic cells is a _______

A

lipid bilayer

79
Q

What are the major eukaryotic membrane lipids

A
  • phosphoglycerides
  • sphingolipids
  • cholesterol
    all of which contribute to strength of membrane
80
Q

The plasma membrane of bacteria and eukaryotes both have _____

A

phospholipids

81
Q

The plasma membrane of eukaryotic cells have ______ which participate in a variety of cellular processes

A

microdomains (lipid rafts)

82
Q

Unlike the ______ in the cell wall of Bacteria and Archaea, many eukaryotes lack or have a chemically distinct cell wall

A

peptidoglycan

83
Q

Cell walls of photosynthetic algae are composed of

A
  • cellulose
  • pectin
  • Silica
84
Q

Cell walls of fungi are composed of

A
  • Cellulose
  • Chitin
  • Glucan
85
Q

____ are the most prominent external structures observed on eukaryotic cells

A

cilia and flagella

86
Q

how are cilia and flagella of a eukaryotic cell different

A
  • cilia are typically only 5 to 20 micrometers while flagella are 100 to 200 micrometers long
  • their patterns of movement are usually distinctive
87
Q

substance inside plasma and outside nucleus

A

Cytoplasm membrane

88
Q

fluid portion of cytoplasm

A

cytosol

89
Q

Cytoskeleton is

A

microfilaments, intermediate filaments, microtubules

90
Q

movement of cytoplasm through cells

A

Cytoplasmic streaming

91
Q

80S ribosomes are found where in eukaryotic cells

A
  • membrane bound: attached to ER

- Free: in cytoplasm

92
Q

70S ribosomes are found where in eukaryotic cells

A
  • In chloroplasts and mitochondria
93
Q

bacterial ribosomes are what size

A

70s

94
Q

An 80S ribosome are composed of

A

-a dimer of 60S and 40S subunit

95
Q

The 60 S subunit is composed of 3 rRNA molecules which are ____, _____, and _____

A

5S, 28S, and 5.8S rRNAs

96
Q

The 40S subunit is composed of 1 rRNA (_____), and ____ proteins

A

18S rRNA and 30 proteins

97
Q

organelle that contains chromosomes

A

Nucleus

98
Q

organelle that is the transport network

A

ER

99
Q

Organelle that functions in membrane formation and secretion

A

Golgi complex

100
Q

Organelle that functions in digestive enzymes

A

Lysosome

101
Q

Organelle that brings food into cells and provides support

A

Vacuole

102
Q

Organelle that functions in cellular respiration

A

Mitochondrion

103
Q

Organelle that functions in photosynthesis

A

Chloroplast

104
Q

Organelle that functions in oxidation of fatty acids and destroys hydrogen peroxides

A

Peroxisome

105
Q

Organelle that consists of protein fibers and centrioles

A

Centromere

106
Q

_____, ____ and ____ are all thought to have evolved from bacterial cells that invaded or were ingested by early ancestors of eukaryotic cells

A
  • Mitochondria
  • Hydrogenosomes
  • Chloroplasts
107
Q

Mitochondria are very similar to extant _____

A

bacteria

108
Q

Chloroplasts are very similar to extant _____

A

cyanobacteria

109
Q

” the power house of the cell” are found in most eukaryotic cells

A

Mitochondria

110
Q

Site of tircarboxylic acid activity

A

mitochondria

111
Q

Organelle where ATP is generated by electron transport and oxidative phosphorylation

A

Mitochondria

112
Q

The Mitochondria is about the same size as ___ cells

A

bacterial

113
Q

Mitochondria reproduce by _____ as do bacterial cells

A

binary fission

114
Q

The outer membrane of mitochondria contain ____ similar to the outer membrane of Gram-negative bacteria

A

porins

115
Q

The inner membrane of mitochondria are highly fold to form ______ and is the location of enzymes and electron carriers for _____ and _____

A

cristae, electron transport and oxidative phosphorylation

116
Q

The mitochondrial matrix is enclosed by ______

A

inner membrane

117
Q

The mitochondrial matrix contains ribosomes (_____ the same as _____) mitochondrial DNA (may be _____ like ____ DNA)

A

70S, same size as bacterial ribosomes, closed circular like bacterial DNA

118
Q

The mitochondrial matrix contains enzymes of the tricarboxylic acid cycle and enzymes involved in _____ of fatty acids

A

catabolism

119
Q

Small energy conservation organelles in some anaerobic protists

A

Hydrogenosomes

120
Q

Hydrogenosomes descended form common ____ ancestor

A

mitochondrial

121
Q

Hydrogenosomes have a ____ membrane, ____ cristae, and usually ___ DNA

A

double, no, lack

122
Q

Hydrogenosomes ATP is generated by _____ process rather than respiration

A

fermentation

123
Q

What are the products of ATP production in Hydrogenosomes

A

CO2, H2, and acetate

124
Q

What are plastids

A

cytoplasmic organelles of photosynthetic protists and plants

125
Q

Pigment containing organelles observed in plants and algae that are the site of photosynthetic reactions

A

Chloroplasts

126
Q

Chloroplasts are surrounded by ____ membrane

A

double

127
Q

The stroma (matrix) of a chloroplast is within the inner membrane and contains

A
  • DNA
  • Ribosomes
  • Lipid droplets
  • Starch granules
  • Thylakoids
128
Q

What are Thylakoids

A
  • flattened, membrane delimited sacs

- site of light reactions (trapping of light energy to generate ATP, NADPH, and oxygen)

129
Q

stacks of thylakoids are called

A

grana

130
Q

____ is the site of dark reactions of photosynthesis (formation of carbohydrates from water and carbon dioxide)

A

Stroma

131
Q

many algal chloroplasts contain a _____, which participates in polysaccharide synthesis

A

pyrenoid

132
Q

Molecular unity basic to bacterial, archaeal, and eukaryotic cells

A
  • biochemical processes, metabolic pathways

- genetic code

133
Q

Differences in eukaryotic cells from bacterial and archaeal

A
  • eukaryotic nucleus (membrane-enclosed nucleus)
  • larger, more complex (archaea and bacteria are about the size of mitochondria and chloroplast and have no organelles)
  • meiosis, mitosis (archaea and bacteria lack both)
  • complex processes (bacteria and archaea cannot perform endocytosis, intracellular digestion, directed cytoplasmic streaming, and ameboid movement)