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Micro Exams > Exam 3 > Flashcards

Exam 3 Flashcards

1
Q

active immunity

A

individuals receive immune stimulus that activates B and T cells to produce antibodies
- memory of antigen
- several days to develop

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2
Q

passive immunity

A

individual receives antibody from another human or animal
- no memory of antigen
- no antibody production

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3
Q

vaccine

A

exposure to antigen which triggers adaptive immune response

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4
Q

immunization

A

either attenuated or inactivated
- with live cells or virus are more effective

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5
Q

hypersensitivity

A

host damage
- antibody mediated or cell mediated
- diseases are categorized by antigens and effector mechanisms that produce disease

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6
Q

immediate hypersensitivity

A

allergy
- antibody mediated
- caused by release of vasoactive products from IgE antibody coated mast cells

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7
Q

delayed-type hypersensitivity

A

cell mediated
- tissue damage

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8
Q

autoimmune disease

A

when T and B cells are activated to produce immune reactions against self proteins
- host damage
- some diseases caused by autoantibodies

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9
Q

immunodeficiency

A
  • humans with deficiency in B cells are prone to bacterial infections
  • T cell deficiencies are prone to viral infections and cancers
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10
Q

SCIDS

A

deficiency in both B and T cells

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11
Q

AIDS

A

caused by HIV infection thats kills CD4 + T cells

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12
Q

viruses

A

not cellular
- don’t display their characteristics apart from their living host cells

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13
Q

prokaryotes

A

appeared 3.5-3.8 billion years ago
- most diverse group
- habitats: ubiquitous
- few cause diseases

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14
Q

arrangement of cocci

A

single, diplococci, tetrads, staphylococci, streptococci, sarcina

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15
Q

coccobacillus

A

rod is short and roundish
- arrangement:
single, diplococci, streptobacilli, palisades

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16
Q

vibrio

A

gently curved singly occurring rods

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17
Q

spirilium

A

bacterium having a slightly curled or spiral-shaped body

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18
Q

spirochete

A

periplasmic flagella
- resembles a spring

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19
Q

pleomorphism

A

variations in cell wall structure caused by slight genetic or nutritional differences

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20
Q

prokaryotes different from eukaryotes by:

A
  • lack of nucleus and histones
  • makeup of cell wall, peptidoglycan and other unique chemicals
  • lack of membrane-bound organelles
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21
Q

cell envelope

A
  • outside the cytoplasm
  • two or three basic layers:
    cytoplasmic membrane
    cell wall
    outer membrane (in some)
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22
Q

cytoplasmic membrane

A

surrounds cytoplasm
- lipid bilayer with proteins embedded
- selectively permeable

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23
Q

cell wall

A

shape of bacterium
- strong structural support
- keeping the bacterium from bursting (lysis) or collapsing
-certain drugs target this
- gains rigidity from peptidoglycan

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24
Q

peptidoglycan

A

repeating framework of sugar and proteins
- provides a strong but flexible support framework
- not found in archaea or eukarya

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25
Q

gram-positive cell wall

A

thick, homogenous sheet of peptidoglycan
- contains teichoic and lipoteichoic acid

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26
Q

gram-negative cell wall

A

thin, sheet of peptidoglycan
- thin sheet gives cells more susceptibility to lysis

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27
Q

gram-negative outer layer

A

-lipopolysaccharides signaling molecules and receptors
-porin proteins special membrane channels

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28
Q

diff. in cell envelope structure

A
  • outer membrane of gram-negative
  • alcohol based compounds
  • Treatment of infections caused by gram-negative bacteria requires drugs that can cross the outer membrane
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29
Q

(nontypical) Acid-Fast bacteria

A
  • mycobacterium and norcardia
  • mycolic acid
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30
Q

Mycobacterium and Norcardia

A

contain peptidoglycan and stain Gram-positive, but bulk of cell wall is composed of unique lipids

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31
Q

Mycolic acid

A
  • Found in the cell walls of acid-fast bacteria
  • Contributes to the pathogenicity of the bacteria
  • Makes bacteria highly resistant to certain chemicals and dyes
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32
Q

Acid-Fast bacterium

A
  • Mycobacterium tuberculosis, Mycobacterium leprae, and Nocardia species
  • β-Lactams (include Penicillin) are
    ineffective
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33
Q

Archaeal cell walls

A
  • All lack true peptidoglycan structure (pseudomurein)
  • Pseudomurein is immune from destruction by both lysozyme and penicillin
  • Most lack an outer membrane
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34
Q

S-layer

A
  • Found in many Bacteria and nearly all Archaea
  • consists of a paracrystalline monolayer of interlocking molecules of protein or glycoprotein
  • When present, is always the outermost layer of the cell envelope
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35
Q

Mycoplasmas

A
  • Naturally lack a cell wall
  • Sterols in the cell membrane stabilize the cell against lysis
  • Mycoplasma pneumoniae: “walking
    pneumonia”
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36
Q

L forms

A

Some bacteria that naturally have a cell wall but lose it during part of their life cycle
- Role in persistent infections
- Resistant to some antibiotics

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37
Q

Mycoplasma

A
  • MUST contain steroids for membrane stability
  • Highly pleomorphic
  • Smallest prokaryotic organisms grown in cell-free culture medium
  • Parasitic and saprophytic
  • M. pneumoniae
  • they experience little osmotic pressure when living within the cytoplasm of another cell
  • absence of peptidoglycan may help evade the host immune system
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38
Q

Glycocalyx

A

Coating of repeating polysaccharide or glycoprotein units
- Role in biofilm production
- Slime layer: loose, protects against loss of water and nutrients
- Capsule: more tightly bound, denser, and thicker; produce a sticky (mucoid) character to colonies on agar

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39
Q

Capsules

A
  • Formed by many pathogenic bacteria
  • Have greater disease-causing abilities
  • Protect against host white blood cells called phagocytes
  • Helps prevent cell dehydration
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40
Q

Appendages

A
  • Motility: flagella and axial filaments
  • Attachment points or channels: fimbriae, pili, hami, and nanotubes/nanowires
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41
Q

Flagellum

A

Primary function is motility
* Three distinct parts:
1. Filament
2. Hook (sheath)
3. Basal body

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42
Q

Chemotaxis

A

Movement of bacteria in
response to chemical signals

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43
Q

Phototaxis

A

response to light signals

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44
Q

Chemotaxis function

A

Runs (linear directions) and tumbles
(stop and go)

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45
Q

Arrangement of Flagella

A

Polar arrangement: flagella attached at one or both ends of the cell
Monotrichous: single
flagellum
Lophotrichous: small bunches
or tufts of flagella emerging
from the same site
Amphitrichous: flagella at
both poles of the cell

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46
Q

Peritrichous arrangement

A

flagella are dispersed randomly over the surface of the cell

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47
Q

Periplasmic Flagella (Axial Filaments)

A

Internal flagellum enclosed in the space between the cell wall and the cytoplasmic membrane

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48
Q

Spirochetes

A

corkscrew-shaped bacteria
- possess an unusual, wriggly mode of locomotion

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49
Q

Archaella

A

proteins are unrelated to those of
flagella, more closely related to type IV pili
- Somewhat simpler than flagella
- generally slower than bacterial flagella

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50
Q

Fimbriae

A

Small, bristle-like fibers sprouting off
the surface of many bacterial cells
- Allow tight adhesion between fimbriae and epithelial cells, allowing bacteria to colonize and infect host tissues
- Mutant forms of these pathogens that lack fimbriae are unable to cause infections

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51
Q

Pili

A
  • Used in conjugation between bacterial cells
  • Type IV pilus can transfer genetic material, act like fimbriae and assist in attachment, and act like flagella and make a bacterium motile
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52
Q

Type IV pili

A

Provides a mechanism for binding to the epithelial cells
- Major contributor to the infectiousness of:
* Neisseria gonorrhoeae (gonorrhea)
* Vibrio cholerae (cholera)
* Streptococcus pyrogenes (strep throat and scarlet fever)

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53
Q

Nanotubes

A

Very thin, long, tubular extensions of the cytoplasmic membrane
- Used as channels to transfer amino acids or to harvest energy by shuttling electrons to iron-rich substances (“breathing rock instead of oxygen”)

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54
Q

Hamus/Hami

A

Present within the SM1 group of
Archaea
“Tiny grappling hook”
- Aids in biofilm formation
- Ecological strategy that helps trap scare nutrients within habitat

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55
Q

cell inclusions

A

Inclusions function as energy reserves, carbon or phosphorus reservoirs, and/or have special functions
- Enclosed by thin protein membrane
- Reduces osmotic stress
- Storing carbon or other substances in an insoluble form within the cytoplasm reduces osmotic stress and takes up less space compared with storing these substances in a soluble form

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56
Q

Gas Vesicles

A

structures that confer buoyancy and
allow the cells to position themselves in regions of the water column that
best suit their metabolisms

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57
Q

Magnetosomes

A

impart a magnetic dipole on a cell,
allowing it to orient itself in a magnetic field

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58
Q

Endospore

A
  • Dormant bodies
  • Produced by some Gram-positive bacilli
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59
Q

Vegetative cell

A
  • metabolically active
  • Endospores resist extremes of heat, drying, freezing, radiation, and chemicals that would kill vegetative cells
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60
Q

The life cycle of an endospore-
forming bacterium

A

vegetative cell → endospore →
vegetative cell
- Sporulation
- Germination

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61
Q

Sporulation

A

The process of cellular
differentiation that results in endospore formation

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62
Q

Germination

A

The process of an endospore converting back to a vegetative cell rapidly

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63
Q

The Medical Significance of Bacterial
Endospores

A

anthrax
tetanus
gas gangrene
botulism
gastrointestinal disease

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64
Q

bacterial chromosome

A

The hereditary material of most bacteria exists

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65
Q

where is DNA aggregated?

A

nucleoid

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66
Q

Plasmids

A
  • Nonessential pieces of DNA
  • Confer protective traits such as drug resistance and toxin and enzyme
    production
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67
Q

Ribosomes

A

Site of protein synthesis

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68
Q

Cytoskeleton

A
  • Arranged in helical ribbons around the cell
  • Contribute to cell shape
  • Have also been identified in archaea
  • Unique to non-eukaryotic cells - may be a potential target for antibiotic
    development
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69
Q

Archaea

A
  • The domain Archaea is named for the Archaean eon
  • live in extreme environments
    (Extremophiles)
  • Now known to occupy a wide range of habitats
  • More closely related to domain Eukarya than bacteria
  • Share rRNA sequences not found in bacteria
  • Protein synthesis and ribosomal subunit structures are similar
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70
Q

Phylogeny of the major
taxonomic orders within
the domain Archaea

A
  • Vast majority of Archaea are difficult to grow in culture
  • The use of metagenomics and single-cell genome sequencing has led to an explosion in our understanding of the phylogenetic and physiological diversity of the
    archaeal domain
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71
Q

Bergey’s Manual of Systematic Bacteriology

A

rRNA sequencing

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72
Q

Bergey’s Manual of Determinative Bacteriology

A

phenotypic characteristics

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73
Q

Bacterial species of Archaea

A

Should share at least 95% of their genes as matches

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74
Q

Subspecies, strain, or type - Archaea

A

Bacteria of the same species that have differing characteristics

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75
Q

Serotype

A

Representatives of a species that stimulate a distinct pattern of antibody (serum) responses because of unique surface molecules

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76
Q

Cell inclusions in prokaryotic cells can serve to?

A
  • Store energy rich compounds
  • Physically position cells in the
    environment for survival
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77
Q

acute respiratory infections

A

kill more than 4 million
people a year

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78
Q

what is the most common of all human diseases?

A

respiratory infections

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79
Q

Aerosols

A

important for person-to-person
transmission of many infectious diseases

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80
Q

Respiratory infections

A

Most pathogens survive poorly in air; thus, they are effectively transmitted only over short distances
* Transmission can also occur via fomites
* Thick cell walls have an advantage

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81
Q

The upper and lower respiratory tracts

A

offer different environmental
niches and favor different microbes
- Can set the stage for secondary infections

82
Q

Upper Tract Infections

A

Typically, acute and non-life-threatening

83
Q

Lower Tract Infections

A

Often chronic; Can be threatening in certain individuals

84
Q

Streptococcal Diseases

A
  • Infections occur if host defenses are weakened or a new, highly virulent strain is introduced
  • Encapsulated strains are pathogenic (harder to kill)
  • Often treatable by antimicrobial agents
  • More virulent types are beta-hemolytic (lyse red blood cells)
85
Q

Streptococcus pyogenes

A

Causative agent of strep throat
- Can also cause infections of the inner ear, mammary glands, and skin as impetigo
- Rare cases can cause severe systemic infections and necrotizing fasciitis
- No vaccine currently available

86
Q

group A streptococci

A

responsible for streptococcal toxic shock syndrome and scarlet fever
- produce a pyrogenic exotoxin

87
Q

Streptococcus pneumoniae

A

Causative agent of pneumonia
- Common secondary infection
- often the cause of
death in elderly persons whose death is reported to be from “respiratory failure.”
- Vaccine available and recommended for high- risk populations

88
Q

Diphtheria

A

Causative agent is Corynebacterium diphtheriae
- (typically infects young children)
- DTaP vaccine is highly effective
- Toxoid: a chemically modified toxin from a pathogenic microorganism, which is no longer toxic but is still
antigenic
- Some strains produce an exotoxin that causes a pseudomembrane in the patient’s throat

89
Q

Tetanus

A

Causative agent is Clostridium tetani
- Common in soil contaminated with animal fecal wastes
- Microbe is an obligate anaerobe → entrance wound must match growth
conditions— e.g. improperly cleaned deep wounds such as those caused by rusty/dirt-contaminated nails
- recovery from tetanus does not provide immunity because the amount of toxin needed to
cause the symptoms is too little to be immunogenic

90
Q

symptoms of tetanus

A

caused by an extremely potent neurotoxin, that is released upon
death and lysis of the bacteria
- It enters the CNS via the peripheral nerves or the blood. The bacteria
themselves don’t spread from the infection site, and there is no inflammation

91
Q

Pertussis (Whooping Cough) causative agent?

A

Causative agent is Bordetella pertussis

92
Q

Tetanus causative agent?

A

Causative agent is Clostridium tetani

93
Q

Diphtheria causative agent

A

Causative agent is Corynebacterium diphtheriae

94
Q

Streptococcus pneumoniae causative agent

A

Causative agent of pneumonia

95
Q

Pertussis (Whooping Cough)

A

An acute, highly infectious respiratory disease
* Common in school-age children
- There has been a consistent upward trend of infections since the 1980s
- Inadequately immunized children, adolescents, and adults are at high risk for acquiring and spreading pertussis
Preventable and treatable → DTaP vaccine

96
Q

DTaP

A

DTaP is a combination vaccine used to provide immunity against 3
serious diseases (Diphtheria, tetanus, and pertussis [whooping
cough])
- children 6 weeks to 7 years

97
Q

Tdap

A

used to boost immunity against the same 3 diseases
- Tdap contains a lower dose of vaccine
- adults and children 10 or older

98
Q

Tuberculosis (TB) causative agent?

A

Causative agent is Mycobacterium tuberculosis

99
Q

Tuberculosis (TB)

A

Transmitted by airborne droplets
- top infectious disease killer worldwide
- Primary infection (initial infection)
- Post-primary infection (re-infection)
* Chronic

100
Q

Hansen’s disease (Leprosy) causative agent?

A

Causative agent: Mycobacterium leprae

101
Q

Hansen’s disease (Leprosy)

A

Transmitted by direct contact as well as airborne
- not very contagious
- Less contagious than TB
- survive ingestion by macrophages and eventually invade cells of the peripheral nervous system, where their presence causes nerve damage
- Death usually results not from the leprosy itself, but from complications and secondary illnesses

102
Q

Hansen’s disease (Leprosy) what drug causes noncontagious?

A

sulfone drugs

103
Q

Tuberculoid (neural) leprosy

A

characterized by a vigorous immune response and a good prognosis for spontaneous recovery → Less pronounced lesions
- Tuberculoid disease occurs in people with effective immune reactions

104
Q

most serious form of leprosy?

A

lepromatous (progressive) leprosy
- Characterized by folded, bulblike lesions on the body
- Severe untreated cases of leprosy → disfiguring lesions lead to destruction of peripheral nerves

105
Q

Meningitis

A

inflammation of the meninges, the membranes that compose the protective covering of the central nervous system (spinal cord and brain)
- Caused by many microbes: viruses, bacteria, fungi, and protists

106
Q

Severe bacterial form of the disease called infectious meningitis, is caused by?

A

Neisseria meningitidis (meningococcus)

107
Q

Neisseria meningitidis

A

frequently present in the nose and throat of carriers without
causing disease symptoms → reservoir of infection → transmission by droplet aerosols or
direct contact with secretions
- Many produce a capsule that protects them from phagocytosis

108
Q

Meningitis is characterized by

A

sudden onset of a headache accompanied by vomiting and a stiff
neck, and its seriousness is underscored by the fact that meningitis can progress to coma and death in less than a day
- Most distinguishing feature → rash
- Mostly caused by an endotoxin
- Vaccine available (1982)
- In the United States, sporadic meningococcal outbreaks occur among college students

109
Q

meningococcemia

A

a condition characterized by intravascular coagulation and tissue
destruction (gangrene), shock, and death in over 10% of cases

110
Q

Staphylococcus Infections

A

Commonly infect skin and wounds
- Potent virulence factors including:
* Hemolysins (Lyses red blood cells)
* Coagulase (Clots blood)
* Leukocidins (Lyses white blood cells)

111
Q

Toxic shock syndrome (TSS)

A

Symptoms of TSS result from an exotoxin → recruits large
numbers of T cells → major inflammatory response (frequently
fatal)

112
Q

Staphylococcus aureus, what was the first antibiotic used?

A

Penicillin

113
Q

what did doctors switch to for Staphylococcus aureus?

A

methicillin
Methicillin worked for about 20 years
* Populations evolved resistance to it.
* MRSA = methicillin-resistant S. aureus

114
Q

MRSA

A

methicillin-resistant S. aureus

115
Q

what do doctors treat MRSA with? (last resort)

A

Doctors treat MRSA with the antibiotic vancomycin, one of the
“drugs of last resort.”

116
Q

VRSA

A

vancomycin-resistant S. aureus

117
Q

Enterococcus

A

These enterococci contained a vancomycin-resistance gene
identical to the one in MRSA → VRSA.
* This suggests that VRSA had acquired vancomycin resistance
from Enterococcus.

118
Q

Sexually Transmitted
Infections (STIs)

A

Caused by a variety of bacteria, viruses, protists, and even fungi
- Pathogens are generally only found in body fluids from the genitourinary tract that are exchanged during sexual activity
- Note the downward trend in disease incidence after the introduction of antibiotics and the upward trend in the incidence of gonorrhea after the introduction of birth control pills

119
Q

Gonorrhea causative agent?

A

Causative agent: Neisseria gonorrhoeae

120
Q

Gonorrhea

A

Does not survive away from mucous membranes of the pharynx, conjunctiva, rectum, or genitourinary tract
* Can only be transmitted via person-to-person contact
asymptomatic in women:
Untreated gonorrhea can lead to pelvic inflammatory disease
males:
painful infection of the urethral canal
- Infants born to infected mothers may acquire eye infection

121
Q

Syphilis causative agent?

A

Caused by Treponema pallidum

122
Q

Syphilis

A

Transmitted via tiny breaks in the skin epithelial layer
- Can be transmitted from an infected woman to the fetus during pregnancy (congenital syphilis)
- Penicillin is highly effective for primary and secondary stages
Human Experiments:
Tuskegee Experiment (1932-1972)

123
Q

Rickettsial Diseases

A

small bacteria that have strict intracellular existence in vertebrates
- have not been cultured in artificial culture media

124
Q

Rocky Mountain spotted fever

A

Rickettsia rickettisii – ticks

125
Q

Epidemic typhus, Typhus Fever

A

Rickettsia prowazekii – lice

126
Q

Endemic typhus

A

Rickettsia typhi – fleas

127
Q

Epidemic typhus, Typhus Fever (Rickettsia prowazekii – lice)

A

a problem among troops in wartime because of the unsanitary, cramped conditions
- typhus caused more military deaths than did combat
- Mortality rate of as much as 30%
- through the skin when a puncture caused by a louse bite becomes contaminated with louse feces
- rash in the armpits
- Complications from untreated typhus: damage to the central nervous system, lungs, kidneys, and heart
- Vaccine is available

128
Q

Lyme Disease causative agent?

A

Causative agent: Borrelia burgdorferi

129
Q

Lyme Disease

A

Most prevalent arthropod-borne disease in the United States
- Spread by the deer tick
- Initial symptoms of Lyme disease include headache, backache, chills, and fatigue
- During the initial stages, Lyme disease can be treated with antibiotics
- Chronic stage develops in weeks to months
- No toxins or virulence factors have been identified but the pathogen triggers a strong immune response

130
Q

Plague

A

Plague has caused more human deaths than any other bacterial disease in recorded history
- can be treated if it is rapidly diagnosed

131
Q

Plague causative agent?

A

Caused by Yersinia pestis
-Disease of domestic and wild rodents
* Fleas are intermediate hosts and vectors that spread plague between
mammalian hosts
* Humans are accidental hosts

132
Q

Bubonic

A

Y. pestis grows in lymph nodes → swelling (buboes)
- treated with antibiotics

133
Q

Pneumonic

A

Y. pestis is directly inhaled or reaches the lungs via the blood or lymphatic circulation (90% of untreated cases are deadly in 48hrs)

134
Q

Septicemic

A

rapid spread through the bloodstream → so severe that
death often occurs before diagnosis

135
Q

Anthrax causative agent?

A

Causative agent is Bacillus anthracis

136
Q

Anthrax

A

Identified by Robert Koch → used to develop his principles for linking
cause and effect in infectious disease—Koch’s postulates
- Natural reservoir is soils → primarily associated with farm animals
- Endospores enhance ability to disseminate B. anthracis
Produces a unique capsule → does not stimulate the immune system
* Produces exotoxins → interfere with phagocytosis
* Grows within macrophages → eventually killing it → dispersing into
the bloodstream
* Treatable with antibiotics (if done early)
* Vaccine is available for high-risk individuals
* Use as a potential bioterrorism or biological warfare agent

137
Q

Cutaneous Anthrax

A

most common
* Entered through break in the skin → forms pustule of necrotic tissue

138
Q

Intestinal Anthrax

A

Ingestion of endospores in undercooked meat

139
Q

Respiratory Anthrax

A

Most severe, nearly always fatal
* Inhalation of endospores (systemic → septic shock)

140
Q

Cholera causative agent?

A

Severe gastrointestinal diarrheal disease caused by Vibrio cholerae

141
Q

Cholera

A

Typically transmitted through ingestion of contaminated water
- Largely restricted to developing countries

142
Q

V. cholerae

A

attaches to epithelial cells in the small intestine, where it grows and releases cholera toxin
- causes fluid losses of up to 20 liters
per person per day → severe dehydration

143
Q

Typhoid Fever (Enteric Fever) causative agent?

A

Causative agent: Salmonella enterica

144
Q

Typhoid Fever: Salmonella enterica

A

the most important waterborne pathogenic bacteria

145
Q

Food poisoning (also called food intoxication)

A

Disease that results from ingestion of
foods containing preformed microbial toxins
- The microorganisms DO NOT have to grow in the host

146
Q

Food infection

A

Microbial infection resulting from the
ingestion of pathogen-contaminated food followed by GROWTH of pathogen in the host

147
Q

Microbial sampling for foodborne
disease

A

Eight microorganisms account for the great majority of foodborne illness:
Salmonella
Listeria monocytogenes

148
Q

Salmonellosis causative agent?

A

gastrointestinal illness caused by foodborne Salmonella infection
- Caused by eating food contaminated with Salmonella or
handling Salmonella-infected animals

149
Q

Salmonella

A

ingested in food or water invades phagocytes and grows as an intracellular pathogen

150
Q

Listeriosis causative agent?

A

Causative agent: Listeria monocytogenes
- Acid-, salt-, and cold-tolerant and facultatively aerobic
- L. monocytogenes was known to cause stillbirth and neurological disease in animals
- dangerous during pregnancy
- Listeriosis is the fourth most common cause of bacterial meningitis

151
Q

Listeriosis

A

A gastrointestinal food infection that may lead to bacteremia (bacteria in the blood) and meningitis
- minor foodborne pathogen
- Excreted in animal feces → is widely distributed in soil and water
- wide variety of foods

152
Q

Intracellular pathogen

A

Virulence factor: Engulfment of the pathogen by phagocytes results in the growth and proliferation of the bacterium
- Primarily in the liver
- Unusual capability of moving directly from one phagocyte to an adjacent one

153
Q

Eukaryotes

A
  • appeared 1.8 billion years ago
  • evolved from (LUCA)
  • last common ancestor of all eukaryotic cells was a single-celled microorganism closely related to Archaea
154
Q

Microbial members of domain Eukarya

A

much more genetically and ecologically diverse than larger eukaryotes
- Eukarya limited range of metabolic diversity (what they can use for energy)

155
Q

Theory of Endosymbiosis

A

prokaryotic cells trapped inside other
prokaryotic cells

156
Q

Primary Endosymbiosis

A

endosymbiotic acquisition by a eukaryotic host cell of a respiring bacterium or a phototrophic cyanobacterium, followed by
evolution of the endosymbiont into mitochondria or chloroplasts

157
Q

Secondary endosymbiosis

A

endosymbiotic acquisition by a mitochondrion- containing eukaryotic cell of a red or green algal cell, which ITSELF contains a chloroplast derived from primary endosymbiosis
- Occurred multiple times within the Eukarya, giving rise to a diversity of phototrophic
eukaryotes

158
Q

Endosymbiotic Theory Evidence

A

Similarity between organelles of modern eukaryotic cells and the structure of bacteria

159
Q

Mitochondria and Chloroplast

A
  • Capable of independent division
  • Contains a circular chromosome with bacterial DNA sequences
  • Prokaryotic ribosomes (70S)
  • Contain bacterial membranes and can be
  • inhibited by drugs that affect only bacteria
160
Q

Endosymbiotic Theory

A

An intracellular bacteria
- Mitochondria’s closest relative are
rickettsias

161
Q

Eukaryotic Cilia

A
  • Similar to flagella in structure, but are smaller and more
    numerous
  • Found only in a single group of protozoa and certain animal
    cells
162
Q

Eukaryotic Flagella

A

X10 thicker than bacterial flagella

163
Q

The Glycocalyx

A

An outermost layer that comes into direct contact with the environment
- Composed of polysaccharides
* A network of fibers
* A slime layer
* A capsule

164
Q

The Cell Wall

A

fungi and most algae
- structural support
- Fungal: Thick inner layer of polysaccharide fibers composed of chitin or cellulose. Thin outer layer of
mixed glycans
- Algae: Varied in chemical composition: various sugars along with minerals such as silicon dioxide and calcium carbonate

165
Q

The Cell Membrane

A

Typical bilayer of phospholipids in which protein molecules are embedded
- Contain sterols (cholesterol) of various kinds which provide
stability
- Cytoplasmic membranes selectively permeable barriers in transportation

166
Q

The Nucleus

A

Most prominent organelle of eukaryotic cells
- Separated from the cell cytoplasm by an external boundary called the nuclear envelope which is perforated with pores
- center is nucleolus

167
Q

Nucleolus

A

where components of ribosomes are
made

168
Q

Rough ER

A

ER with ribosomes attached
- make membrane proteins and secretory protein

169
Q

Smooth ER

A

without ribosomes attached
- makes lipids, fats
- Detoxifies drugs and poisons
liver has smooth ER

170
Q

Golgi Apparatus

A

Molecule processing “the warehouse”
- Receives, refines, stores, and distributes chemical products of
the cell
- works with transport vesicles

171
Q

Lysosome

A

the cell’s garbage disposal
* A membranous sac of hydrolytic enzymes that can digest (hydrolyze) macromolecules
* work best in acidic environments
* Autophagy: Lysosomes use enzymes to recycle the cell’s own organelles and macromolecules (self engulfing)

172
Q

Vacuoles

A

Membrane-bound sacs containing fluids or solid particles to be digested, excreted, or stored
- storage compartments

173
Q

Mitochondria

A

Composed of a smooth, continuous outer membrane with an inner folded membrane
- Generate energy for the cell
- Divide independently of the cell
- Contain circular strands of DNA and
prokaryotic ribosomes

174
Q

Chloroplasts

A

found in algae cells and plant cells
- Capable of converting energy from sunlight into chemical energy through photosynthesis
- Produce oxygen gas as a by-product of photosynthesis

175
Q

Ribosomes

A

Scattered freely in the cytoplasm and cytoskeleton
* Attached to the rough endoplasmic reticulum
* Appear inside mitochondria and chloroplasts (70S prokaryotic size)
- Multiple ribosomes are often found arranged in short chains called polyribosomes (polysomes)

176
Q

Ribosomes sizes

A

Eukaryotic ribosome is 80S
Prokaryotic ribosome is 70S

177
Q

The Cytoskeleton

A

network of fibers extending throughout the cytoplasm
- It gives animal cells shape
and support
- Controls intracellular traffic
- It gives all cells some ability
to control their movement

178
Q

Kingdom Fungi (Eumycota)

A

Large variety and complexity

179
Q

Macroscopic fungi

A

(mushrooms, puffballs, gill fungi)

180
Q

Microscopic

A

fungi (molds, yeasts)

181
Q

Cell walls fungi

A

Chitin

182
Q

Cell membranes fungi

A

Sterols (ergosterol)
* Target in anti-fungal drugs

183
Q

Two basic morphological types

A

Hyphae
Yeasts

184
Q

Yeasts

A

Round to oval shape
* Asexual reproduction, budding

185
Q

Hyphae

A

Long, threadlike cells found in the bodies of filamentous fungi
(molds)

186
Q

Pseudohypha

A

chain of yeast cells

187
Q

dimorphic

A

Some fungal cells are considered dimorphic and can take either
form, depending on growth conditions → particularly characteristic of some pathogenic molds

188
Q

Heterotrophic fungi nutrition

A

acquire nutrients from a wide variety of organic substrates

189
Q

Saprobic fungi nutrition

A

these substrates from the remnants of dead plants and animals in soil or aquatic habitats

190
Q

Parasitic fungi nutrition

A

grow on the bodies of current or previously living animals or plants, although very few require a living host

191
Q

fungi

A
  • Fungi penetrate the substrate and secrete enzymes that reduces it to small molecules that can be absorbed by the cells
  • often found in nutritionally poor or adverse environments, and those with high salt or sugar content
192
Q

Benefits of Fungi

A
  • decomposing organic matter
  • stable associations with plant roots
  • engineered to produce large quantities of antibiotics, alcohol, organic acids, and vitamins
  • eaten or used to provide flavoring to
    food
193
Q

Morphology of Fungi

A
  • microscopic fungi grow in loose associations or colonies
  • yeast: soft, uniform
    texture and appearance
  • molds: hairy
194
Q

Spore Formation

A

dormant survival structures
- Can be dispersed through the environment by air, water, and living things

195
Q

Asexual Spore Formation

A

Sporangiospores
Conidiospores or conidia

196
Q

Sporangiospores

A

formed by successive
cleavages within a saclike head
- asexual

197
Q

Conidiospores or conidia

A

free spores not enclosed by a spore-bearing sac
- no head
- asexual

198
Q

Sexual spores

A

vary from simple fusion of fertile hyphae of two different strains, or as a complex union of male and female structures

199
Q

Zygospores (sexual)

A

sturdy diploid spores formed when hyphae of two opposite strains
(called the plus and minus strains) fuse and create a diploid zygote

200
Q

Agricultural Impact of Fungi

A
  • Reduces crop production
  • Can cause disease in domestic animals consuming contaminated feed crops
201
Q

Penicillium notatum mold

A

a very common decomposer of
citrus fruit, is known for its velvety texture and typical blue-green color

Micro Exams (4 decks)

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