Chapters 2 & 3 Flashcards Preview

BIO111: Microbiology > Chapters 2 & 3 > Flashcards

Flashcards in Chapters 2 & 3 Deck (133):
0

Prokaryote

"pre-nucleus"
No nucleus or other internal membrane bound organelles

1

Eukaryote

"true nucleus"
Membrane bound organelles and membrane systems

2

3 Main shape of Bacteria

Coccus (Cocci)
Bacillus (Bacilli)
Spirillus (Spirilli)

3

Coccus (Cocci)

Spherical

4

Bacillus (Bacilli)

Rods

5

Spirillus (Spirilli)

Spirals

6

Vibrio

Comma shaped cells

7

Spirochete

More tightly coiled spirals

8

Pleomorphic

Irregular shaped

9

Di
(prefix)

Two

10

Strep
(prefix)

long chain

11

Staph
(prefix)

Irregular clusters

12

Coccus

1 singles sphere shaped cell

13

Diplococcus

2 sphere shaped cells connected

14

Tetrad

clusters of four cocci together

15

Streptococcus

long chains of cocci

16

staphylococcus

irregular clusters of cocci

17

Sarcina

Clusters of 8, 18, 32 or more cocci cells in a perfect cube shape

18

Bacillus

single rod shaped cell

19

Diplobacillus

2 rod shaped bacilli connected

20

Streptobacillus

Chains of rod shaped bacilli

21

Palisades

side-by-side arrangement of bacilli

22

4 biochemisty groups

Proteins
Carbs
Lipids
Nucleic Acids

23

Proteins

amino acids joined by peptide bonds, often with complex foldings
Ex. enzymes, most hormones, collagen

24

Carbohydrates

basic structure CH2O
simple sugars Glucose (C6H12O6)
Comples carbs (polysaccharides like cellulose and chitin)

25

Lipids

hydrophobic
-triglycerides and phospholipids contain glycerol and fatty acids
-steroids (cholestrol and sex hormones) are variations of 4 carbon ring structure

26

Cell Membrane
(Prokarya)

Phospholipid bilayer (40%) embedded with proteins (60%)
Fluid mosaic model

27

3 layers of the cell envelope
(Prokarya)

Cell membrane
Cell wall
Glycocalyx

28

Phospholipid Bilayer
(Prokarya)

One phospholipid molecule has:
Two hydrophobic tails
Hydrophilic head of glycerol and phosphate

29

Phospholipid comparisons

-Bacteria and Eucarya - fatty acid tails
- Archaea - tails made of isoprene with branches
Also differences in glycerol and how glycerol links to hydrophobic tails

30

Prokaryote membrane functions

Transport
Enzymes

31

Transport
(Prokaryote membrane functions)

Selectively permeable
(Osmosis, Facilitated diffusion, active transport, secretion)
Integral Proteins (Carrier Proteins, Channel proteins -aqua proteins for faster water transport)

32

Enzymes
(Prokaryote Membrane functions)

Metabolic Pathways
1. Synthesis of extracellular structures
2. Electron transport and ATP synthesis

33

Difference between Animal and Fungal cell membranes

Animal - cholesterol
Fungal - ergosterol

34

Eucarya Cell Membrane

Receptor proteins - cell communication can recognize foreign cells
Sterols - give strength to cell membranes
Lipid Rafts - groups of proteins and lipids

35

Cell Wall

- Lacking in animal cells and some protists(protozoa)
- Found in most bacteria and Archaea
- Bacteria genus Mycoplasma has NO CELL WALL (sterols for strength)

36

Cell Wall function

Maintain Shape
Protection from environment
Protection from osmotic pressure

37

Bacteria normally live in what kind of solution

Hypotonic

38

Peptidoglycan composition

Only found in bacteria
Two major subunits: Alternating glycan molecules and tetrapeptide chains

39

Glyan Molecules

simple sugar + amino acid (amino sugars)

40

Two types of glycans

NAM - N-acetylmuramic acid
NAG - N-aceytlglcosamine
alternating chains NAG_NAM_NAG_NAM

41

Tetrapeptide chains

String of 4 amino acids
Link together the glycan chains
- peptide interbridges (Gram +)
- direct connection (Gram - )

42

Gram Stain

Hans Christian Joachim Gram in 1882

43

Gram Positive Cell Wall

One thick peptidoglycan layer (upto 30 layers)
Teichoic Acid
Periplasm

44

Teichoic Acid

Amino acids, sugars, glycerol, phosphate - from cell membrane through cell wall
Present only in Gram +

45

Periplasm

Gel like substance in between membrane and peptidoglycan

46

Gram Negative Cell Wall

2 parts outter and inner
1. thin Peptidoglycan + Periplasm = periplasmic space
2. Phospholipids
Lipopolysaccharides (LPS)
Lipoproteins
Porin

47

Penicillin

interferes with synthesis of peptide inter-bridges in Gram positive

48

Lysozyme

an enzyme that digests glycan (NAG NAM)

49

Why are gram - bacteria less sensitive to antimicrobial medication

because of its outer membrane

50

Glycocalyx

Outside cell wall
Usually made of polysaccharides
2 kinds: Capsule or Slime layer

51

Glycocalyx function

1. Protect from dehydration
2. Attachment to tissue (biofims and teeth)
3. Protection from white blood cells (phagocytosis)

52

Bacteria Flagella

- long, thin - special flagella stain
- Rigid, hair-like - made of FLAGELLIN
- Rotate 360
- Used to enter host cell

53

Structure of Bacteria Flagella

Filament
Hook
Basal body

54

Filament

spiral chains of protein form a hollow tube

55

Hook

curved protein structure, connects filament to cell structure

56

Basal body

ringed protein structure, anchors to cell membrane and cell wall, "motor"of flagella

57

-Trichous

hair

58

Mono

one

59

Amphi

both

60

Lopho-

tuft

61

Peri-

Around

62

Flagella arrangement found in....

ALL spirilla
half of bacilli
few cocci

63

Eucarya flagella

- covered with plasma membrane
- groupings of mictotubule proteins
- Basal body - anchor, different arrangement of microtubules than flagellum
-Whip like motion

64

Axial fibrils

found in spirochetes
used to burrow into host cell

65

Gliding

polysaccharide slime or surface proteins used for movement

66

Pili

-Shorter and thinner than flagella
- long hollow filament of PILIN proteins
- Adhesive tip for attachment

67

2 Types of Pili

Fimbriae and sex pili

68

Fimbriae

Usually many found on a bacteria cell
Stick to surfaces and other fimbriae
Allow for invasion of host tissue
Example: E.Coli

69

Sex Pili

- longer than fimbriae, less numerous (usually 1 or 2)
- In Gram - bacteria and some Gram +
- Used in conjugation

70

Conjugation in Sex pili

Sex pilus directly links the cytoplasm of one cell to another, plasmid DNA travels through the sex pilus

71

Nucleic Acids

DNA and RNA

72

Monomer

nucleotide = pentose sugar, nucleobase (A,G,C,T,U) and phosphate

73

DNA

double helix, sugar-phosphate backbone

74

RNA

shorter, single stranded
rRNA, mRNA, tRNA involved in protein systhesis

75

Bacterial Chromosome

-Single, circular, double stranded DNA
- contains genes that code for cell maintenance and growth
- Contains 3000 - 4000 genes
- Area where DNA is found is called NUCLEOID
- DNA is supercoiled with various proteins (histones only in Archaea and Eucarya)

76

Area where DNA is found in a bacteria chromosome

Nucleoid

77

Plasmids

Very small, circular pieces of DNA
- Free floating in cell
- contain few genes to 1000 genes
- supercoiled

78

Plasmids, are they essential

Not essential but helpful
drug resistance
enzyme and toxin production

79

What domain are Plasmids found

Bacteria, Archaea and SOME Eucarya

80

Ribosomes

Bacterial cell contains 15,000
Protein synthesis
60% rRNA and 40% proteins

81

Ribosome subunits

2 (small and large)

82

Bacteria and Archaea subunits

30S and 50S = 70S total

83

Eucharya subunits

40S and 60S = 80S

84

Mitochondria and chloroplast Sunits

70S ribosomes

85

S units

Svedberg units - measure size of ribosome and subunits
Higher S = heavier RNA

86

Endosymbiotic theory

Engulfs the cell and uses it instead of digesting it

87

Cytoplasmic Inclusions/Granules

-Storage of organic energy (glycogen and PHB)
- gases for floatation in aquatic systems
-storage of essential elements as inorganic crystals (sulfer granules & volutin)
- Some enclosed by membranes (storage particles)

88

Volutin

phosphate storage (metachromatic)

89

What are Endospores

-Small, protected, dormant bacteria
- Cannot divide, degrade or synthesize while dormant
- Genetically identical to original cell

90

When are Endospores formed

- in unfavorable conditions (starvation, desiccation)
- Germinates under favorable conditions to become a vegetative cell
- For survival, not reproduction
- Energetically very costly to produce

91

Endospores - WHO

- Only some Gram-positive rods
- Bacillus and Clostridium species
- Diseases from endospore forming bacteria - botulism, tetanus

92

A normal cell when not dormant is called a

vegetative cell

93

Endospores How they form

- One spore formed from one bacteria cell
- DNA duplcates, septum forms in cell
-"mother cell" engulfs "forespore"
- Peptidoglycan material added to forespore
- Mother cell degrades

94

Endospore layers

Spore coat
Cortex
Core

95

Spore coat
(endospore)

outer layer - protein - protection from chemicals and enzymes
sometimes EXOSPORIUM is present

97

Cortex
(endospore)

middle layer - peptidoglycan - keeps spore dry, helps to resist heat and radiation

97

Extreme Resistance of Endospores

- high temperatures, desiccation, freezing, radiation, and many chemicals of toxins
-Endospores 1000s of years old can still germinate
- Can quickly return to vegetative state
- preventing endospore contamination: moist heat of pressurized steam using an autoclave

98

Core
(endospore)

inner part - contains and protects bacteria's DNA
Core also contains calcium salts and dipicolinic acid

99

Ecoli facts

Gram -
Normal microbiota or possibly virulent
single bacillus with flagella and fimbriae
Many different strains ex. Shiga toxin producing E.Coli

100

Element

Matter made of one type of atom

101

How many naturally occurring elements

92

102

Which 4 elements are most common in organisms***

Oxygen, Carbon, Hydrogen, Nitrogen, Phosphorus

103

Atoms

the smallest part of an element that still has the properties of that element

104

3 subatomic particles that compose atoms

Protons
Neutrons
Electrons

105

Protons
(location and charge)

Nucleus
+

106

Neutrons

Neutral
Nucleus

107

Electrons
(Location and charge)

Negative
Shells, Orbitals

108

Atomic Number

the number of protons

109

atomic weight

the total number of protons and neutrons

110

What is an isotope

Atoms for the same element with different numbers of neutrons

111

What is a molecule

two or more atoms (ions) chemically bonded

112

Chemical bond

energy that holds atoms (ions) together

113

Covalent bond

form by equal sharing of a pair of electrons between two atoms
Polar (unequal sharing)
Nonpolar (equal sharing)

114

Ionic Bond

formed because of the transfer of electrons between two atoms

115

Hydrogen bond

the attraction of the positive hydrogen end of a polar molecule to the negative nitrogen or oxygen end of another polar molecule.
THE WEAKEST BOND

116

What is an Ion

an electrically charged atoms: an atom either gains or looses an electron

117

anion

an atom that gains an electron and becomes -

118

cation

an atom that loses an electron and becomes +

119

pH

measurement of hydronium H+ ions in a solution
0-14

120

buffer

reacts with a strong acid/base to for a weak acid/base; resists pH change

121

Diffusion

movement of molecule or ions from an area of high concentration to an area of low concentration of that molecule achieving equilibrium

122

Osmosis

movement of water molecules from an area of high concentration of H20 to an area of lower concentration through a selectively permeable membrane

123

Hypertonic

Higher concentration of solutes outside the cell

124

Hypotonic

lower concentration of stuff outside the cell

125

Isotonic

same osmotic pressure as body fluids

126

What happens if a cell is placed in a hypertonic or hypotonic solution

hypertonic - cell will shrink
hypotonic - cell will expand and possibly explode

127

Mitochondria
(function)

ATP production

128

Chloroplast
(function)

Use photosynthesis to make ATP for energy

129

Ribosome
(function)

Protein synthesis

130

Golgi apparatus

refines processes and packages proteins from ribosomes into packages

131

Rough Endoplasmic Reticulum
(function)

molecular transport of protein

132

Three organelles which have a double membrane and contain DNA

Mitochondria
Chloroplast
Nucleus