Bacteria, Protists, and Fungi Flashcards

1
Q

“…evolution produces a tree, not a ladder — and we are just one of many twigs on the tree.”

A

Phylogenetic trees depicts the evolutionary relationships of about 3,000 species throughout the Tree of Life. Less than 1 percent of known species are depicted.

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2
Q

Domain

A

the highest level of hierarchy

Three domains:
Bacteria, Archaea, and Eukarya

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3
Q

Bacteria

A

no nucleus, single-celled

PROKARYOTES

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4
Q

Archaea

A

no nucleus, single-celled

PROKARYOTES

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5
Q

Eukarya

A

have a nucleus
cells can be either single-celled or multicelled

EUKARYOTES

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6
Q

The origin of prokaryotes

A

At least 3.6 billion years old
Fossil stromatolites (still can be found today); consist of layers of bacterial mats.
First prokaryotes likely appeared much earlier.

Early photosynthetic prokaryotes produced an oxygen atmosphere.

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7
Q

Most common form of movement in prokaryotes

A

Flagella

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8
Q

Prokaryotes Disease: cause about half of all human diseases

A

TB (Mycobacterium tuberculosis)*
Cholera (Vibrio cholerae) outbreaks in untreated water
Syphilis (Treponema pallidum)* why easily treated
Lyme disease (Borrelia burgdorferi)* most widespread pest-carried disease in U.S.
Anthrax (Bacillus anthracis)
Legionnaire’s disease (Legionella sp.)
Escherichia coli (part of our natural gut flora, but type O15:H7 is dangerous.)
Plague (Yersinia pestis)

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9
Q

Syphilis

A
Bacterial Disease
Syphilis can be easily treated with antibiotics, usually by injections.
Gonorrhea (Neisseria gonorrhoeae)
Strep infection (Streptococcus sp.)
Chlamydia trachomatis* most common STD
Clostridium botulinum*  BOTOX 
MRSA (now VRSA?)

(BUT Harmful prokaryotes are in the minority)

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10
Q

Prokaryotes: What we don’t think of

A

Collective mass is 10 times of eukaryotes
If reproduction unlimited colony could outweigh Earth in 3 days.
Differences between bacteria and eukaryotes allow antibiotics to
disrupt RNA and ribosomes (erythromycin and tetracycline)
disrupt bacterial cell walls

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11
Q

Prokaryotes: What we don’t think of

A

Collective mass is 10 times of eukaryotes

If reproduction was unlimited colony could outweigh Earth in 3 days.

Differences between bacteria and eukaryotes allow antibiotics to disrupt RNA and ribosomes (erythromycin and tetracycline) and to disrupt bacterial cell walls.

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12
Q

Bacteria

A

All share a common ancestor
Originated ~ 3.8 billion years ago

Single-celled prokaryotes

Asexual reproduction
Also exhibit horizontal gene transfer

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13
Q

Bacterial Classification

A

3 basic shapes:
Coccus (round)
Bacillus (rod)
Spirillum (spiral)

Gram Staining differentiates between 2 major groups based on cell wall structure:
Gram-Positive
Gram Negative

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14
Q

Humans and Bacteria

A

There are 10 times as many bacterial cells in your body than human cells!

There are more bacterial cells in your stomach than there are people on the planet

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15
Q

Benefits of Bacteria

A

“normal flora”

Probiotic therapy: swamp your body with benign/helpful bacteria to outnumber harmful bacteria fight bacteria with bacteria

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16
Q

Thermus aquaticus

A

One of the most important bacterial discoveries
Used in polymerase chain reaction (PCR)
Found in hot springs

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17
Q

Future Possibilities

A

Bacteria as data storage
http://news.discovery.com/tech/biotechnology/bacteria-work-as-hard-drives-110110.htm

Detecting Landmines
http://www.treehugger.com/clean-technology/scientists-create-bacteria-that-lights-up-around-landmines.html

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18
Q

Archaea

A

Similarities with bacteria:
appearance
prokaryotes
single-celled

Big differences with bacteria:
DNA
cell wall chemical composition
flagella

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19
Q

Archaea cont…

A

“Extremophiles”

  • hydrothermal vents
  • acidic water
  • salty water
  • places in which most proteins would denature

Found almost everywhere, including in your intestines:
break down bonds in beans, release methane

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20
Q

Bells and Whistles of Eukarya

A

Nucleus

Cytoskeleton:
Controls shape of cell and movement of internal elements

Mitochondria:
Allow oxidative metabolism

Chimeric genome:
Some genes from Bacteria, some from Archaea, and some unique to Eukarya.
(for some, chloroplasts)

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21
Q

In the course of evolution, genomes grow. HOW?

A

Eukaryotes typically have 5-20X number of genes of prokaryotes

New genes arise by duplication of existing genes– with subsequent divergence of function

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22
Q

the constraints on single cells

A

Cells must stay small because of

  1. water
  2. nutrients
  3. wastes
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23
Q

Tissues

A

Tissues are not just aggregations of cells – the cells in tissues are connected by intercellular junctions and function as a unit

Junctions hold cells together and also allow communication between cells (e.g., transfer of small molecules)

24
Q

The evolution of multicellularity

A

Likely began with coloniality with subsequent cell specialization.

Coloniality has evolved independently in many prokaryote and protist lineages.

Multicellularity has evolved independently in several eukaryote groups.

What is significance of independent development?

25
Q

Protists

A

Extremely diverse

Share one feature: eukaryotic

Defined by exclusion:
They just do not belong to any other kingdom.

Classification is being reconsidered; there may be as many as 20 kingdoms

26
Q

Protist diversity

A

Range from single-celled protists to enormous multicellular organisms (algae)

“Protists” exhibit wide range of “body plans” and include the most complex living cells

27
Q

Protist Classification

A
“Traditional” groupings:
Animal-like protists – protozoans
(chemoheterotrophs)
Plant-like protists – algae
(photoautotrophs)
Fungus-like protists – molds
Chemoheterotrophs (often saphrophytic-[feeds on dead or decaying matter])
28
Q

chemoheterotrophs

A

An organism deriving energy by ingesting intermediates or building blocks that it is incapable of creating on its own.

Most chemoheterotrophs obtain energy by ingesting organic molecules like glucose.

Word origin: Gk: 
Chemo = chemical, 
hetero = (an)other, 
troph = nourishment
Related forms: chemoheterotrophic (adjective)

Also called: chemotrophic heterotroph

Chemotrophs are organisms that obtain energy by the oxidation of electron donors in their environments. These molecules can be organic or inorganic. The chemotroph designation is in contrast to phototrophs, which utilize solar energy.

29
Q

protozoans

A

Animal-like protists;

chemoheterotrophs

30
Q

algae

A

Plant-like protists;

photoautotrophs

31
Q

molds

A

Fungus-like protists;

Chemoheterotrophs (often saphrophytic)

32
Q

Protist Classification

A

“Traditional” groupings:

Animal-like protists – protozoans
(chemoheterotrophs)

Plant-like protists – algae
(photoautotrophs)

Fungus-like protists – molds
Chemoheterotrophs (often saphrophytic-[feeds on dead or decaying matter])

33
Q

chemoheterotrophs

A

An organism deriving energy by ingesting intermediates or building blocks that it is incapable of creating on its own.

Most chemoheterotrophs obtain energy by ingesting organic molecules like glucose.

Word origin: Greek: 
Chemo = chemical, 
hetero = (an)other, 
troph = nourishment
Related forms: chemoheterotrophic (adjective)

Also called: chemotrophic heterotroph

Chemotrophs are organisms that obtain energy by the oxidation of electron donors in their environments. These molecules can be organic or inorganic. The chemotroph designation is in contrast to phototrophs, which utilize solar energy.

34
Q

photoautotrophs

A

An organism obtaining energy from sunlight as its source of energy to convert inorganic materials into organic materials for use in cellular functions such as biosynthesis and respiration.

In order to capture light as source of energy, photoautotrophs carry out photosynthesis, converting energy from sunlight, carbon dioxide and water into organic materials. Photoautotrophs provide nutrition for many forms of life. They include the plants, algae and certain protists bacteria.

Word origin: Greek: 
photo = light, 
auto = self, 
troph = nourishment
Related forms: photoautotrophic (adjective)
35
Q

“Plant-Like” Protists

A

Algae: photosynthetic protist living in water
Range in size
Use different photosynthetic pigments: yellow, gold, brown, red and green

36
Q

Seaweed

A

Plant-like protists

a macroscopic, multicellular, benthic marine algae

Used as a source of food for humans:
Sherberts, chocolate milk, cheeses, instant pudding, mayonnaise, ice cream, etc

Used in fertilizer, soil conditioner, animal feed, facial mask, massage gel, vitamins, seaweed baths, toothpaste, make-up, soaps, shampoo, shaving cream, shower gel…..

37
Q

“Fungus-Like” Protists

A

Plasmodial Slime Molds
Cellular Slime Molds
Slime Mold

38
Q

“Animal-Like” Protists

A

Most are unicellular

Giardia
Chagas disease
African sleeping sickness
Malaria

39
Q

Fungi: Basics

A

Domain: Eukarya
Kingdom: Fungi

Similar to plants, but

  • lack chloroplasts
  • do not photosynthesize
  • some are unicellular (ex: yeast)
  • heterotrophic (mostly decomposers)
40
Q

fungi are more closely related to

A

animals than plants

41
Q

Relationship of Fungi to Animals

A

Molecular genetic studies suggest fungi share a common ancestor with animals

Features shared with animals:

Cells walls contain chitin (as in some animals), not cellulose (as in plants)

Carbohydrates stored as glycogen (as in animals) and not as starch (as in plants)

42
Q

Currently, 5 phlya of fungi

A

Chytrids (water and soil)
Zygomycetes (rot produce, fast growing)
Glomeromycetes (90% of plants have these on roots)
Ascomycetes (morels, truffles, bread molds, yeast)
Basidiomycetes (toadstools)

43
Q

Fungi feeding

A

Absorptive heterotrophs (like many prokaryotes)

“Digest then ingest” - digestive enzymes secreted into surroundings; fungus then absorbs the digested products

Most are decomposers: Some are parasitic, and some symbiotic

44
Q

Fungi: Structure

A

The body of most fungi is a network of thin filaments which

  • provides a large surface area for absorbing nutrients
  • penetrates the fungus’s food source
  • secrete enzymes that break down organic molecules
  • absorb resulting nutrients
45
Q

hyphae

A

tiny filaments of fungi that form a network underground and a “body” above

46
Q

mycelium

A

the interwoven network of hyphae

underground (or in a substrate)

47
Q

sporulation

A

the release of spores

48
Q

hyphae

A

tiny filaments of fungi that form a network underground and a “body” above

49
Q

mycelium

A

the interwoven network of hyphae underground (or in a substrate)

50
Q

Fungi: Chytrids

A

primitive fungi that produce swimming spores
- flagellum

Chytridomycota: Killing The Frogs

51
Q

Zygomycota

A

Ruining Your Food

52
Q

Glomeromycota

A

The Feeling is Mutual

Mycorrhizal fungi form symbiotic relationships with plant roots.

  • Helps plant better absorb nutrients
  • Fungus gets carbohydrates from plant
  • mutually beneficial relationship
  • very common
53
Q

Essential ECOLOGICALLY: Glomerocytes and mycorrhizae

A

Associated with > 90% of plants.
Improve water/mineral uptake by plant roots.
Plant roots provides carbohydrates to fungus.
ALL glomerocytes form arbuscular mycorrhizae.

54
Q

Ascomycota

A

“Bringing Friends Together”

Important ECONOMICALLY
Saccharomyces cerevisiae = Ascomycete yeast:
- single-celled fungus
- mostly asexual
- inhabits liquid or moist environments
- responsible for bread and wine and beer

Important GASTRONOMICALLY
Some of the most famous edible mushrooms are ascomycetes
- Morels
- Truffles
- Other molds in cheeses
55
Q

Ascomycota

A

“Bringing Friends Together”

Important ECONOMICALLY
Saccharomyces cerevisiae = Ascomycete yeast:
- single-celled fungus
- mostly asexual
- inhabits liquid or moist environments
- responsible for bread and wine and beer

Important GASTRONOMICALLY
Some of the most famous edible mushrooms are ascomycetes
- Morels
- Truffles
- Other molds in cheeses

Important MEDICALLY (good and bad)
- Penicillium mold (ascomycete) - the source for penicillin, the first antibiotic.
Alexander Flemming, Nobel Prize in 1945 for discovery of penicillen

  • Claviceps purpurea, which infects rye plants, is responsible for ergot poisoning.
  • Vaginal yeast infection (Candida albicans)
56
Q

Basidiomycota

A

Tasty, Fun or Deadly?

toadstoals

57
Q

Fungi: Lichens

A

Relationship between a fungus and photosynthesizer (green algae or cyanobacteria)

Can live in extreme conditions and is important in making soil, but is sensitive to pollution

Fungus provides protected environment and minerals for the autotrophs, while the autotrophs supply carbohydrates

Lichens often the first colonizers of bare rock and are likely one of the first land colonizers

Can resist harsh, exposed conditions