Microorganisms and the biosphere

Question 1

When was the earth anoxic?

Answer 1

During the first 2 billion years of Earth’s existence, its atmosphere was anoxic (O2 was absent), and only nitrogen carbon dioxide and a few other gases were present

Question 2

How old is the earth?

Answer 2

4.6 billion years old

Question 3

When were bacteria and archea found?

Answer 3

Cellular life, in the form of Bacteria and Archaea, was present on Earth by 3.8 billion years ago (bya).

Question 4

Cyanobacteria relevance

Answer 4

The evolution of phototrophic bacteria called Cyanobacteria caused Earth’s atmosphere to become oxygenated over time

Question 5

Phototrophic microorganisms

Answer 5

Organisms that harvest energy from sunlight
Cyanobacteria—oxygen-producing (oxygenic) phototrophs
Cyanobacteria evolved nearly a billion years later and began the slow process of oxygenating Earth’s atmosphere.

Question 6

Microbial mats

Answer 6

the structures that these early phototrophs lived in structures and are still found on Earth today

Question 7

Multicellular life evolution

Answer 7

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

Question 8

Existence of plants and animals on earth

Answer 8

only existed for about half a billion years.

Question 9

Three major lineages of microbial cells

Answer 9

the Bacteria
the Archaea
the Eukarya

Question 10

Last universal common ancestor (LUCA):

Answer 10

Examination of the common genes reveals that all three domains have descended from a common ancestor

Question 11

Microbial Activity in the Biosphere

Answer 11

The total amount of carbon present in all microbial cells is a significant fraction of Earth’s biomass.
Total amount of nitrogen and phosphorus within microbial cells is almost four times that in all plant and animal cells combined.
A major fraction of the total DNA in the biosphere (about 31%), and their genetic diversity far exceeds that of plants and animals.

Question 12

Microbial Abundance in the Biosphere

Answer 12

Constitute a major fraction of global biomass.
The key reservoirs of nutrients essential for life.
There are an estimated 2x1030 microbial cells on Earth
To put this number in context, the universe, in all its vast extent, is estimated to contain merely 7x1022 stars.

Question 13

extremophiles

Answer 13

Such microorganisms are called extremophiles and their properties define the physiochemical limits to life

e.g.
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

Question 14

dead zone

Answer 14

Manipulate the microbial life which determines the ecosystem which results in dead zones e.g. putting organic waste in the ocean which kills the microbial life and then there is NO life

Question 15

Biosphere predeiciton

Answer 15

Only by understanding microorganisms and microbiology can we predict and minimize the effects of human activity on the biosphere that sustains us.

Question 16

Microbes in the body

Answer 16

More than 200 microbial genes are present for every human gene.
Microbes determine your cravings, socialisatoins, mood, personality
MICROBES ARE KEEPING US ALIVE

Question 17

Microbiologists study

Answer 17

Microorganisms function
Advanced human health and welfare
In food and agriculture
Produce valuable human products
Generate energy
Clean up the environment.

Question 18

Vaccination

Answer 18

process of training your body/cells for right and adequate immune response

e.g. troops fighting enemies. Troops can regonise eachother because of uniforms “antigens”, in order to differentiate from enemies: they have different uniforms “antigens”. To make troops know what to look for in enemy, sample enemy is shown in front of them so troops can regonise them. This is what happens in a vaccine. Little bit of vaccine is shown so body can recognise it and differentiate it in the future.
- Food and water are the easiest way for microorganisms to get into the body.

Question 19

Disease:

Answer 19

any change or alteration in the normal regulation of our metabolism or cellular structure that causes some damage

Question 20

Infection

Answer 20

starts replication process but no damage- no symptoms- once symptoms present it is disease

Question 21

Antibiotic

Question 22

Rumen:

Answer 22

Microorgansims that are responsible for the enzymatic action of breaking down cellulose that cannot be broken down by animal cells
e.g. cows have seconf stomach that contains enzymes which cleave the plant proteins so they can be absorbed and utilized

Question 23

Where are microorganisms most prevelent in gut?

Answer 23

Most of these organisms cannot survive in the stomach acid so the number increases in small intestine but most are in the colon as the pH is 7 and this is a more liveable environment for these microorganisms
Vitamins/nutritents sythensised: e.g. Vit B12, short chain fatty acids

Question 24

Do humans have a rumen?

Answer 24

Humans do not have a rumen- the gut contains microorganisms that have enzymes that can break down/cleave the plants so we can utilize their nutritents

Question 25

Do all food spoilage lead to illness

Answer 25

Food spoilage is not neccessaryily the same microorganisms that cause disease
Some microorganisms sit on the food without affecting it, but produce toxins that leads to poinsing when we ingest them

Question 26

Characteristics for pathogenic microbial growth:

Answer 26

Optimal temp for growth is 37
Optimal pH is 7

Question 27

What are the benefits of fermentation?

Answer 27

The products of microbial fermentation affect the flavor and taste of foods and can prevent spoilage as well as the growth of deleterious organisms.

Microbial production of lactic acid in cheeses, yogurt, and buttermilk are all produced by microbial fermentation of dairy products.
Microbial lactic acid improves the shelf life of fermented products and prevents the growth of foodborne pathogens.
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.
The fermentative activities of yeast are essential
for baking (by generating carbon dioxide to raise the dough)
for the production of alcoholic beverages (by generating alcohol)

Question 28

Fermentation

Answer 28

Form of anerobic catabolism/metabolism
When micro-organism convert organic substances into energy

Question 29

what are the sources of fermentation?

Answer 29

Major fermentations in various fermented foods. It is the fermentation product (ethanol, or lactic, propionic, or acetic acids) that both preserves the food and renders in it a characteristic flavor.

Question 30

Industrial Microbiology

Answer 30

The use of microorganisms as tools for major industries such as pharmaceuticals and brewing.
Bioreactors called fermentors make large amounts of products
Antibiotics
Enzymes
Alcohol
Certain other chemicals

Question 31

Biotechnology

Answer 31

Employs genetically engineered microorganisms to synthesize products of high commercial value, such as insulin or other human proteins, usually on a small scale.

Question 32

Biofuels

Answer 32

Natural gas (methane, ) is a product of the anaerobic metabolism of methanogenic Archaea.
Ethyl alcohol (ethanol) is a major fuel supplement, which
microbial fermentation of glucose obtained from carbon-rich feedstocks such as sugarcane, corn, or rapidly growing grasses.

Biofuels should help cool our planet and are one facet of the “green revolution” many countries support today.

Question 33

Wastewater treatment:

Answer 33

Waterborne diseases such as cholera and typhoid (major killers before the blossoming of microbiology

Question 34

Bioremediation:

Answer 34

Microbes can be used to clean up industrial pollution into nontoxic forms
spilled oil
Solvents
Pesticides
heavy metals
other environmentally toxic pollutants

Question 35

Biofilms

Answer 35

Growth of microorganisms in a community that are attached = biofilm

Question 36

Why are biofilms on medical devices an issue?

Answer 36

on implanted medical devices can cause infections that are extremely difficult to treat.

Question 37

How do microbes contribute to the nutrition of animals such as humans and cows?

Answer 37

Allow for the plants to be broken down into a form that is able to be used by the body

Question 38

Describe several ways in which microorganisms are important in the food and agricultural industries.

Answer 38

Carbon + nitrogen/ fermentation/ biofuel/ medicine- producing insulin/ preservation + production of food

Question 39

What is wastewater treatment and why is it important?

Answer 39

The treatment of contaminated water is important so we are able to recycle and reuse the water and prevent the accumulation of toxic microorganisms that cause disease

Question 40

When and by who was the microscope invented?

Answer 40

microscopist Antoni van Leeuwenhoek
He discovered bacteria in 1676 while studying pepper–water infusions and reported his observations in a series of letters to the prestigious Royal Society of London, which published them in English translation in 1684.

Question 41

Light microscope

Answer 41

the sample is illuminated with visible light

Question 42

Magnification

Answer 42

describes the capacity of a microscope to enlarge an image

Question 43

Resolution

Answer 43

is the ability to distinguish two adjacent objects as distinct and separate.
The limit of resolution for a light microscope is about 0.2 μm

Question 44

Types of lenses

Answer 44

objective
ocular

Question 45

Total magnification

Answer 45

The total magnification of a compound light microscope is the product of the magnification of its objective and ocular lenses

Question 46

Numerical aperture:

Answer 46

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

lenses with higher magnification typically have higher numerical apertures

Question 47

oil-immersion lenses

Answer 47

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.

Question 48

What is the limit of resolution for a bright-field microscope? What defines this limit?

Answer 48

2.2

The limitations of bright-field microscopy include low contrast for weakly absorbing samples and low resolution due to the blurry appearance of out-of-focus material. Colloidal gold nanoparticles can serve as labels in bright-field microscopy due to their large absorption and scattering cross sections.