Beneficial Prokaryotes

Question 1

What are the 2 chemical cycling process that Prokaryotes, Fungi, & Algae play a role in?

Answer 1

• Decomposition

- Fixation

Question 2

What is Decomposition half of the chemical cycle & how to Prokaryotes & Fungi do it?

Answer 2

• Nitrogen, Phosphorus & other atoms of biological systems have all come from the physical environment so when the system’s decay, all these elements are returned to the environment
• So prokaryotes & fungi release a dead organisms atoms to the environment

Question 3

What is the Fixation half of the Chemical Cycle?

Answer 3

-Prokaryotes helping to return elements from inorganic forms to organic forms that heterotrophic organisms can use

Question 4

What 2 elements do Prokaryotes Fixate?

Answer 4

• Carbon

- Nitrogen (can be limiting nutrient for ocean & terrestrial ecosystems)

Question 5

What is the role of Prokaryotes in fixing carbon?

Answer 5

• The organic compounds that plants, algae, & photosynthetic prokaryotes produce from CO2 pass up through food chains to form the bodies of all the ecosystems heterotrophs
• Ancient Cyanobacteria= added oxygen to earth’s atmosphere as a by-product while modern prokaryotes contribute to the production of oxygen

Question 6

What allows Prokaryotes to fix Atmospheric Nitrogen?

Answer 6

• Prokaryotes employ an enzyme complex= Nitrogenase = encoded by a set of nif genes (nitrogen fixation)
• This Nitrogenase complex is extremely sensitive to oxygen & is found in a wide range of prokaryotes

Question 7

What is the form of Nitrogen?

Answer 7

-The nitrogen in the Earth’s atmosphere is in the form of N2 gas= triple covalent bond links 2 nitrogen atoms together & not easy to break

Question 8

How do Prokaryotes fix Nitrogen?

Answer 8

-They use their Nitrogenase to reduce N2 to NH3 (ammonia used to build amino acids & other nitrogen-containing molecules)
-When the organisms die, decomposers return nitogen to the soil as ammonia=converted to NO3- by nitrifying bacteria
(the nitrate can be converted back into molecular nitrogen via Dentrifiers= returning nitrogen to atmosphere)

Question 9

How is Nitrogen Fixation carried out in Aquatic Environments?

Answer 9

• It’s carried out largely by Cyanobacteria (Anabaena)
• The process is strictly anaerobic= cyanobacteria may develop into Heterocysts (specialized nitrogen-fixing cells impermeable to oxygen)

Question 10

How does Nitrogen Fixation carried out in soil?

Answer 10

-It occurs in the roots of plants that harbor symbiotic colonies of nitrogen-Fixing bacteria

Question 11

What is Symbiosis?

Answer 11

-Refers to the ecological relationship between different species that live in contact w/ eachother

Question 12

What is the symbiotic association between nitrogen-fixing bacteria & plant roots?

Answer 12

-Mutualism= a form of symbiosis in which both parties benefit

Question 13

What is Parasitism?

Answer 13

-Form of symbiosis in which one member benefits & the other is harmed

Question 14

Genetic code is….

Answer 14

Universal= human gene can be inserted into a bacterial cell & the bacterium will produce a human protein

Question 15

What is Bioremediation?

Answer 15

-The use of organisms to remove pollutants from water, air & soil

Question 16

What is Biostimulation?

Answer 16

-the addition of nutrients (nitrogen & phosphorous) has been used to encourage the growth of naturally occurring microbes that can degrade crude oil spills & enourage the growth of naturally occuring microbial flora in contaminated ground water

Question 17

What is Halorespiration?

Answer 17

• Chlorinated compounds released into the environment by a variety of sources= serious pollutant
• SO some bacteria can use these compounds for energy by performing reductive dehalogenation= linked to electron transport (halorespiration)

Question 18

What are the 3 forms of Symbiosis?

Answer 18

• Mutualism
• Commensalism
• Parasitism

Question 19

What is Mutualism?

Answer 19

-Form of symbiosis where Both parties benefit

Question 20

What is Commensalism?

Answer 20

-Form of symbiosis where One organism receives benefits while the animal or plant is neither benefited or harmed