lecture 2-23 to post

Question 1

what are community’s built from

Answer 1

community’s are built from a variety of guilds, guilds are metabolically related organisms(co-metabolism)

Question 2

what is a niche

Answer 2

a niche defines the nutrient and enovoirmental conditions which a organisms needs to survive

Question 3

niche vs microenvoirment

Answer 3

niche is the role which the organisms plays in the micoenvoirment

Question 4

what is a microenvoirment

Answer 4

where a orgnisum is and what it metabolises

Question 5

where are extended periods of exponential growth rare to find in nature

Answer 5

b/c in nature a constant flow of nutrients at a stable pH and constant ideal temp is very rare

Question 6

what is the form in which microbs undergo optimal growth in

Answer 6

The state which is most favorable by all microbes in attached to a surface in a biofilm

for microbes to attach to a surface the surface first needs to be pioneered, this is done by pioneer orgnaiusms whuch are able to metabolize raw nutrients creating by products which other organism’s can use to grow and develop .

Question 7

significance of biofilms

Answer 7

They are the main cause fo dental disase, they can cause reduction of waterflow in pipes due to buildup on the pipe wall, they can decrease the quality of potable water, they are also the main cause of infections associated with artificial implants

Question 8

how can biofilms be beneficial

Answer 8

they can filter water such as waste water

They can leach low grade ores

Question 9

what are the top 2 things which microbes compete for

Answer 9

Nutrients and space

Question 10

what is antagonism

Answer 10

a form of competition where one microorganioganism inhibits the growth or limits metabolism of other microorganisms through exterior of a inhibitor or toxic metabolite

Question 11

what is syntropy

Answer 11

where 2 or more microbes worth together to carry out a transformation which neither can do alone these organisums will typically share the same microenvoirment

Examples include
nitrification
sulfate
sulfide

Question 12

Primary relationships between microbs

Answer 12

Commensalism–> one pop benefits and the other is not effects(+ or neutral)

Co-metabolism–> type of commensalism which 2 work together to create a transformation
Synergism–> both benefit this is a form of mutualism

Question 13

where are the biggest C reserves found?

Answer 13

earths crust
humus
land plants

Question 14

what is humus

Answer 14

a complex mixture of decomposing organic material

Question 15

at is the largest contributor of CO2

Answer 15

Microbial decomposition

Question 16

what are the 2 ways which new organic carbon is formed (carbon which can be used by organisms

Answer 16

Oxygenic photosynthesis

Chemosynthesis which is fixation of CO2 by chemolithotrophs

Question 17

what are the major oxidation states of carbon

Answer 17

CH4 methane which is done via methanogens

CO2 which is done via chemoorganotrophs

the production of one or the other depends on the presence of either methanogens or chemoorganotrophs when humus is decomposed

Question 18

what is the process of methanogenesis and what enzyme is involved

Answer 18

this is the formation of methane via
CO2+4H–> CH4+2H2O
mediated via enzyme methyl reductases

Question 19

methanogens

Answer 19

anaerobic archaebacteria
these have a very narrow substrate range so cooperation w other organisms is needed to meet nutrient needs

Question 20

where are methanogenesis most likely to be found (habitat)

Answer 20

Swamps marshes and anaerobic microenvironments

they are often found in these water logged environments bc they have a high aw while remaining anerobic

Question 21

which hydrocarbons are not degraded anaerobically

Answer 21

lignin and aliphatic saturated hydrocarbons

Question 22

methanotrophs

Answer 22

are a specialized subset or methylotrophs which oxidize methane

Question 23

why type of carbon compounds do methylotrophs use

Answer 23

They utilize 1-C compounds as there source of both energy and carbon

Question 24

what is the primary role of the nitrogen cycle

Answer 24

to convert inorganic C to useable organic forms which can be used by other organisms

Question 25

which organisms can preform nitrification

Answer 25

NH4–> NO3
nitrosomonas

Question 26

denitrification

Answer 26

NO3–> N2
Psedomonas

Question 27

N2 fixation

Answer 27

N2+8H–> NH3+H2
free living cyanobacteria
anerobic Rhizobium
Symbiotic Frankia

Question 28

Ammonification

Answer 28

organic N–> NH4
done by many organisms

Question 29

where are the biggest nitrogen pools

Answer 29

the atmosphere=80%N2
Fertile soil which contains 30,000 tons per/acre

Question 30

Nitrification

Answer 30

This is the conversion of ammonia to nitrate by nitrifying microbes

Question 31

Denitrification

Answer 31

Conversion of nitrate to nitrous oxide or N2 via denitrifies(nitate consumption) which is carried out under anerobic conditions

Question 32

what is the cause for the loss of nitrogen from the soil

Answer 32

Denitrification as it facilities the formation of gaseous N2 which causes loss of nitrogen from the soil this is why we have crop rotation as plants such as pea plants have nitrogen fixing bacteria which have a mutualist relationship with the pea plant thus fixing the bacteria into the ground into organic bacteria

Question 33

Ammonification what is it

Answer 33

Decomposition of organic nitrogen compounds creating ammonia as a by product

Question 34

what is nitrogen fixation and what organisms carry it out

Answer 34

Utilization of N2 as a source of nitrogen where N2 is converted to ammonia via aerobic chemoorganotrophs such as azotobacter ssp

Question 35

root nodule bacteria what is it and how does it occur

Answer 35

this is a symbiosis between leguminous plants and gram - bacteria

1. recongition and attachment
2. invasion of root hair
   3.travel via infection thread
   formation of bacteriods
   continnuwed plant cell/bacterial cell division

Question 36

leghemoglobin

Answer 36

contorls O2 binding in Fe protein and controls the O2 levels in root nodual which protects against nitrogenase (oxygen buffer)

Question 37

what are bacteroids

Answer 37

the resluting product from rapid multipulocation of bacteria within the plant cell these bacteria often become swollen and misshapen into branced forms

Question 38

what is symbiosome

Answer 38

these are the bacteriods which are surrounded by proteions of the plant cell membrane

Question 39

what is Assimilatory nitrate reduction

Answer 39

this is the pathway present in all bacteria which reduce nitrate to ammonia

Question 40

What is dissimilatory nitrate reduction

Answer 40

this is a type of nitrate respiration which is a aerobic process which occurs when oxygen levels are low producing nitrite ammonia and N2