metabolic diversity / microbial ecology

Question 1

Robert H Whittaker ?

Answer 1

was the first to exclude Archae and focus on what separates the plantae , Fungi and Animalia

Question 2

Archae ?

Answer 2

single-celled microorganisms with structure similar to bacteria. They are evolutionarily distinct from bacteria and eukaryotes and form the third domain of life. Archaea are obligate anaerobes living in environments low in oxygen

Question 3

monera ?

Answer 3

single cell organism like cyanophylo which a prokaryotic cell organization, such as bacteria. They are single-celled organisms with no true nuclear membrane

Question 4

protista ?

Answer 4

any eukaryotic organism that is not an animal, plant, or fungus. The protists do not form a natural group, or clade, since they exclude certain eukaryotes with whom they share a common ancestor

Question 5

Carl Woese ?

Answer 5

included Archae in his studies for the first time , he realised they branched at the same point as eukaryotes.

Question 6

LUCA ?

Answer 6

last universal common ancestor) that is the root of the tree and where the branches come from. It gives rise to the diversity. Every living organism on this planet is a descendent of LUCA . LUCA had everything that’s universal - enough to live on. In the tree of life metaphor we call LUCA “the root”, but it is really just the top of the trunk. LUCA is not the first cell. The true roots are the chemistry and cells that came before LUCA

Question 7

how old os earth ?

Answer 7

4.6 billion years

Question 8

first cells appeared ?

Answer 8

Earth 3.8 – 3.9 million years ago.

Question 9

what was the first 2 bilion years on earth ?

Answer 9

all life was microbial and there was an anoxic atmosphere (no oxygen) – mainly N2 and CO2. All the organisms had anoxic metabolisms such as methanogenesis. This is the formation of methane by microbes known as methanogens.

Question 10

domain of organisms producing methane ?

Answer 10

domain Archaea, a group phylogenetically distinct from both eukaryotes and bacteria, although many live in close association with anaerobic bacteria

Question 11

anoxic phototrophs ?

Answer 11

non-oxygen evolving) evolved around 3.5 billion years ago.

Question 12

oxygenic phototrophs ?

Answer 12

cyanobacteria evolved (around 2.5 billion years ago) and this allowed development of oxygen-dependent metabolisms and eventual development of multicellular lifeforms. Before oxygen became available every form of life was present in the sea , once oxygen became available the life on land began.

Question 13

what did the 16s rRNA surveys reveal ?

Answer 13

huge amount of diversity in the environment and a large number of novel lineages with no cultivated representatives. The function is unknown.

Question 14

what was the issue with the Camilo Mora et Al research ?

Answer 14

left out all the prokaryotic microbial life and only counted the eukaryotic.

Question 15

what was the estimation of eukaryotic life on earth ?

Answer 15

estimated to be approx. 8.7 x 10^6 species in total

Question 16

what was 10g of soil contain approximately of bacteria and archaea cells ?

Answer 16

10^10

Question 17

what is 99.9% of biological diversity on earth ?

Answer 17

microbial

Question 18

hyperthermophiles ?

Answer 18

organisms that thrive in extremely hot environments , Taq polymerase used in PCR is part of this group. It was named after the bacterium called Thermus aquaticus. The genus that are part of the hyperthermophiles in archea include , Thermococcus , thermoproteus and pyrodictium

Question 19

genus of hyperthermophiles in euryarchea ?

Answer 19

haplophiles

Question 20

alessandro Volta ?

Answer 20

discovered methane which he called combustible air in 1778 while he was studying marsh gas from lake Maggiore.

Question 21

what is the source of methane ?

Answer 21

archaea not bacteria

Question 22

methanogens ?

Answer 22

microorganisms that produce methane as a metabolic byproduct in hypoxic conditions. They are prokaryotic and belong to the domain of archaea. Some genus in the archaea include methanosarcina , methanobacterium and methanoccoccus. The euryarchaea are halophiles.

Question 23

piloric animals will produce what ?

Answer 23

methane when digestion occurs

Question 24

hydrogenothrophic ?

Answer 24

use CO2-type substrates (electrons derived from H2)
• Carbon dioxide (CO2)
• Formate (HCOO-)
• Carbon monooxide (CO

Question 25

methylotrophic ?

Answer 25

methyl substrates
•	Methanol (CH3OH)
•	Methylamine (CH3NH3+)
•	Dimethylamine (CH3)2 NH2+
•	Trimethylamine (CH3)3 NH+

Question 26

acetotrophic ?

Answer 26

acetotrophic substrates
• Acetate (CH3COO-)
• Pyruvate (CH3COCOO-)

Question 27

where do prokaryotes live ?

Answer 27

anywhere there is liquid water and they occur in large numbers. Most of the bacterial cells are relatively small.

Question 28

why do prokaryotes have a small size ?

Answer 28

Small cell size is a way to cope with low substrate availability
• It increases the surface area to volume ratio
• Substrate uptake is via cell membrane proteins.
• Increasing surface area / volume ratio improves the ability to supply nutrients to the cytoplasmic volume

Question 29

oligotrophy ?

Answer 29

Most of the biosphere has low available nutrients or at least one limiting nutrient. oligotrophy (‘small feeding’) is growth at low nutrient concentrations and this occurs in the ocean as there are low nutrients. In nature there is a lower concentration of nutrients compared to in a lab.

Question 30

microcytis bloom ?

Answer 30

occurs as an un natural cyanobacterial bloom due to excessive nutrients ( pollution).

Question 31

lake cisco ?

Answer 31

it is purple and this is due to purple sulphur bacteria. From this pink Himalayan salt is made , as there is a huge cell accumulations up to 108. These can be seen from space.

Question 32

energy source ?

Answer 32

Needed for movement, nutrient transport into cells, biosynthesis

Question 33

Phototrophs ?

Answer 33

photosynthetic, energy from sunlight

Chemotrophs

Question 34

chemotrophs ?

Answer 34

energy from oxidation of chemicals

Question 35

chemolithotrophs ?

Answer 35

energy from oxidation of INORANIC chemicals hydrogen sulfide, sulfur, ammonia, nitrites, hydrogen gas, or iron

Question 36

chemoorganotrophs ?

Answer 36

energy from oxidation of ORGANIC chemicals , this is what humans have energy source from.

Question 37

autotrophs ?

Answer 37

An organism that can make organic molecules from inorganic nutrients.Assimilates C-1 compounds (CO2 or CH4 - USUALLY CO2

Question 38

heterotrophs ?

Answer 38

An organism that cannot make organic molecules from inorganic nutrients
• Depends on OM for energy generation and precursors for cell material

Question 39

photoautotrophs ?

Answer 39

have a light source as their energy source and Co2 as their carbon source. Examples include green sulfur bacteria, Purple sulfur bacteria, Cyanobacteria

Question 40

cyanobacteria ?

Answer 40

Cyanobacteria:
• Use hydrogen atoms from water to reduce carbon dioxide to form carbohydrates
• Produce oxygen gas (oxygenic process)
• First organisms to conduct oxygenic photosynthesis (generated atmospheric O2)
• Significant proportion of marine plankton (and marine microbial food web)

Question 41

lichens ?

Answer 41

an association between two partners: an ascomycete (fungus) and a cyanobacterium. The cyanobacteria provides organic compounds via photosynthesis, and can fix nitrogen. The fungus provides protection, water retention, extracts minerals and nutrients from substrate.

Question 42

photoheterotrophs ?

Answer 42

have a light source as their energy source and organic carbon as their carbon source. Examples include halobacteria , these organisms possess the protein Bacteriorhodopsin .Light energy is used to transfer protons across the membrane out of the cell. This results in the proton gradient being used to generate ATP. This is what gives Halobacteria their distinctive colour.

Question 43

can photoheterotrophs fix CO2 ?

Answer 43

nope

Question 44

chemoautotrophs ?

Answer 44

chemistry as their energy source and Co2 as their carbon source. They fix CO2 to make organic compounds, they obtain energy from (usually inorganic) chemicals. Examples include organisms involved in nitrification

Question 45

chemoheterotrophs ?

Answer 45

organic carbon as their carbon source and chemistry as their energy source. Examples include E.Coli , Pseudomonads , Bacillus species. Probably the most common nutritional mode. They use organic (carbon) compounds for both carbon requirement and energy generation.

Question 46

what has the greatesr metabolic diversity out of the 3 domains .

Answer 46

bacteria and archaea greater than eukaryotes

Question 47

what is the respiration for eukaryotes ?

Answer 47

oxygen respiration with glucode