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Bio 232 > Week 3 > Flashcards

Week 3 Flashcards

1
Q

What are microorganisms?

A
  • the oldest form of life on Earth
  • They have evolved to preform critical functions that sustain the biosphere
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2
Q

How old is the Earth?

A

4.6 billion years old

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3
Q

when did microbial cells first appear?

A

between 3.8 and 4.3 billion years ago

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4
Q

During the first 2 billion years of earth…

A

its atmosphere was anoxic (O2 was absent), and only nitrogen carbon dioxide and a few other gases were present

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5
Q

What was the Earth’s origin like

A

sterile and anoxic

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6
Q

what was present 3.8 billion years ago?

A

bacteria and archaea

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7
Q

what caused Earth to become oxygenated over time

A
  • The evolution of phototrophic bacteria called cyanobacteria
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8
Q

When were current levels of atmospheric O2 achieved?

A

500-800 million years ago

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9
Q

phototrophic microorganisms

A

organisms that harvest energy from sunlight

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10
Q

When did phototrophic microorganisms evolve?

A

within 1 billion years of the formation of Earth

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11
Q

what were the first phototrophs?

A

anoxygenic

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12
Q

Cyanobacteria

A

oxygen-producing phototrophs

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13
Q

When did cyanobacteria evolve

A

nearly a billion years later and began the slow process of oxygenating Earth’s atmosphere

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14
Q

Microbial Mats

A

Microbial Mats: The structures that these early phototrophs lived in structures and are still found on Earth today

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15
Q

Multicellular Life:

A

Evolved after the oxygenation of Earth’s atmosphere, culminating in the plants and animals we know today

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16
Q

How long have plants and animals existed?

A

about half a billion years

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17
Q

How much of life’s history was exclusively microbial?

A

80%

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18
Q

What can Earth be considered?

A

A microbial planet

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19
Q

Three major lineages of microbial cells:

A
  1. The Bacteria
  2. The Archaea
  3. The Eukarya
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20
Q

How many genes are present in cells of all 3 domains

A

approx 60 genes

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21
Q
  • last universal common ancestor (LUCA):
A
  • examination of the common genes reveals that all three domain have descended from a common ancestor
  • Microorganisms fill every habitable environment on Earth
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22
Q

what constitutes a major fraction of global biomass?

A

Microbials

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23
Q

How many stars are there in space?

A

7x10 to the power of 22 stars

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24
Q

How many microbial cells are there on Earth?

A

2x10 to the power of 30 microbial cells

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25
Q

How much nitrogen and phosphorus are present within microbial cells

A

almost 4 times that in all plant and animal cells combined

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26
Q

Extremophiles

A

properties define the physiochemical limits to life

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27
Q

Microbes are abundant in:

A
  • volcanic hot springs
  • glaciers
  • ice-covered regions
  • high-salt environments
  • extremely acidic or alkaline habitats
  • deep in the sea
  • deep in the earth at extremely high pressure
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28
Q

Metabolic activities

A

metabolic activities of microorganisms can see the change the habitats which they live, both chemically and physically, and these changes can affect other organisms

29
Q

How can we predict and minimize the effects of human activity on the biosphere that sustains us?

A

only by understanding microorganisms and microbiology

30
Q

why are microorganisms contributions easy to overlook?

A

because of their small sizes

31
Q

How many microbial genes are present for every human gene?

A

more than 200 microbial genes

32
Q

what do microbial genes do

A

provide benefits and services that are essential to human health

33
Q

What are microbes important to?

A

myriad issues of global importance to humans including climate change, agricultural productivity, and even energy policy

34
Q

Microbiologists study

A
  • microorganisms function
  • Advanced human health and welfare
  • in food and agriculture
  • produce valuable human products
  • generate energy
  • clean up the environment
35
Q

Microbio has fuelled advances in:

A
  • medicine such as vaccination and antibiotic therapy
  • advances in engineering such as water and wastewater treatment
  • advances in food safety such as pasteurization
  • a better understanding of how microorganisms are transmitted
36
Q

Agriculture

A
  • the cycling of nitrogen, sulfur, and carbon
37
Q

Legumes

A
  • a diverse family of plants that include major crop species such as soybeans, peas, and lentils, among others
38
Q

What do legumes live in close association with?

A
  • legumes live in close association with bacteria that form structures called nodules on their roots
39
Q

What does the bacteria that is in close relations with leagues do?

A
  • these bacteria convert atmospheric nitrogen into ammonia through the process of nitrogen fixation. is the major nutrient found in fertilizer
40
Q

what does the rumen contain

A

dense and diverse community of symbiotic microorganisms that digest and ferment cellulose

41
Q

What other things are ruminants

A
  • many domesticated and wild herbivorous mammals - including deer, bison, camels, giraffes, and goats
42
Q

what does the GI tract rely on

A
  • rely on microbial partners for our nutrition
43
Q

how many microbial cells foes the colon contain

A
  • the colon contains about 10 to the power of 11 microbial cells per gram of colonic contents
44
Q

why do humans rely on our gut microbiome for this purpose

A
  • human enzymes lack the ability to break down complex carbohydrates (which can represent 10-30% of food energy)
45
Q

where are microbial cells low?

A
  • low in the very acidic (pH 2) stomach (about per gram)
46
Q

where do microbial cells increase

A
  • increase to about per gram near the end of the small intestine (pH 4-5)
47
Q

Where do maximal microbial cells live?

A
  • Reach maximal numbers in the colon (pH 7)
48
Q

What do microbial cells do?

A
  • in the digestion of complex carbohydrates
  • synthesize vitamins and other nutrients essential to host nutrition
  • The gut microbiome develops from birth, but it can change over time with the human host
49
Q

What food are microorganisms present in?

A
  • food spoilage
  • foodborne disease
  • improve food safety and preserve foods
  • for baking
  • for the production of alcoholic beverages
50
Q

what is a large focus in the food industry

A
  • microbial food safety and prevention of food spoilage is a major focus of the food industry and a major cause of economic loss every year
51
Q

what foods have microbial production

A
  • microbial production of lactic acid in cheeses, yogurt, and buttermilk are all produced by microbial fermentation of dairy products
52
Q

what does microbial lactic acid do?

A

improves the shelf life of fermented products and prevent the growth of foodborne pathogens

53
Q

Lactic acid definition

A
  • Lactic acid - producing bacteria are used to produce a variety of sour-tasting foods, including sauerkraut, kimchi, pickles, and even certain sausages even the production of chocolate and coffee rely on microbial fermentation
54
Q

Industrial microbiology

A
  • the use of microorganisms as tools for major industries such as pharmaceuticals and brewing
55
Q

bioreactors called fermentors make large amounts of products:

A
  • antibiotics
    • enzymes
    • alcohol
    • certain other chemicals
56
Q

Biotechnology

A
  • employs genetically engineered microorganisms to synthesize products of high commercial value, such as insulin or other human proteins, usually on a small scale
57
Q

Natural gas (methane)

A

product of the anerobic metabolism of methanogenic Archaea

58
Q

what alcohol is a major fuel supplement

A

ethyl alchohol (ethanol) major fuel supplement, which microbial fermentation of glucose obtained from carbon-rich feedstocks such as sugarcane, corn, or rapidly growing grasses

59
Q

what should biofuels do?

A
  • biofuels should help cool our planet and are one facet of the “green revolution” many countries support today
60
Q

Wastewater treatment

A

waterborne diseases such as cholera and typhoid (major killer before the blossoming of microbiology

61
Q

Bioremediation: microbes can be used to clean up industrial pollution into nontoxic forms:

A
  • Spilled oil
  • Solvents
  • Pesticides
  • Heavy metals
  • Other environmentally toxic pollutants
62
Q

Where are biofilms:

A
  • in pipes and drains can cause fouling
  • blockages in factory settings and pipelines
  • in sewers
  • in water distribution systems
  • ship’s hulls can caused marked reductions in speed and efficiency
  • in tanks that store oil and fuel, leading to spoilage of these products
  • on implanted medical devices can cause infections that are extremely difficult to treat
63
Q

Who is Robert Hooke

A
  • english mathematician and natural historian
64
Q

What did Robert Hooke write?

A

his famous Micrographia, the first book devoted to microscopic observations
Hooke illustrated many microscopic images including the fruiting structures of molds this was the first known description of microorganisms

65
Q

Microscopy

A
  • bright-field
  • phase-contrast
  • differential interference contrast
  • dark-field
  • Fluorescence
66
Q

Numerical Aperture

A
  • The limit of resolution for a light microscope is a function of the wavelength of light used and the light-gathering ability of the objective lens
67
Q

What is there a correlation between

A

between the magnification of a lens and its numerical aperture

68
Q

lenses with higher magnification….

A

typically have higher numerical apertures

69
Q

Oil immersion lenses

A

Immersion oil increases the light-gathering ability of a lens; that is, it increases the amount of light that is collected and viewed by the lens.

Bio 232 (9 decks)

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