Question 1

Briefly describe what occurs when elemental sulfur is provided externally as an electron donor and how energy is obtained.

Accepted Answer

Elemental sulfur (S⁰) can serve as an ele

Question 2

The ammonia switch- off effect is a(n)

Accepted Answer

A)  reversible reaction that converts ammonia to ammonium. 
B)  irreversible reaction performed by ammonia fixers. 
C)  mechanism where nitrogenase activity is shut down during excess ammonia and resumes when ammonia is limited. 
D)  rapid process used to conserve ATP consumption by ammoniase. 
A)  reversible reaction that converts ammonia to ammonium. 
B)  irreversible reaction performed by ammonia fixers. 
C)  mechanism where nitrogenase activity is shut down during excess ammonia and resumes when ammonia is limited. 
D)  rapid process used to conserve ATP consumption by ammoniase.

Question 3

Phycobiliproteins form into aggregates called________ that attach to the photosynthetic membranes. Cells with an increased number of these structures can grow at________ (higher/lower) light intensities.

Accepted Answer

phycobilis

Question 4

Describe the anammox reaction.

Accepted Answer

During anaerobic conditions, a

Question 5

Carotenoids

Accepted Answer

A)  function primarily as photoprotective agents. 
B)  are hydrophobic pigments that are present in photosynthetic membranes. 
C)  are involved in the capture of light energy. 
D)  do all of the above. 
A)  function primarily as photoprotective agents. 
B)  are hydrophobic pigments that are present in photosynthetic membranes. 
C)  are involved in the capture of light energy. 
D)  do all of the above.

Question 6

Light harvesting protein complexes found in cyanobacteria and chloroplasts in red algae are called

Accepted Answer

A)  phycobiliproteins. 
B)  rusticyanins. 
C)  cytochromes. 
D)  quinones. 
A)  phycobiliproteins. 
B)  rusticyanins. 
C)  cytochromes. 
D)  quinones.

Question 7

H2- oxidizing bacteria are all aerobic.

Accepted Answer

A) True 
 B)False

Question 8

Photosystems I and II normally function in tandem in oxygenic photosynthesis.

Accepted Answer

A) True 
 B)False

Question 9

Explain why most iron- oxidizing bacteria are obligately acidophilic, and discuss some of the environments where these organisms are found.

Accepted Answer

Oxidation of iron at a low pH does not c

Question 10

Organisms that obtain energy from the oxidation of an inorganic compound and require an organic compound as a carbon source are known as________ .

Accepted Answer

The answer of Organisms that obtain energy from the oxidation...

Question 11

Chemotrophic denitrifying bacteria can couple the oxidation of Fe2+ to the reduction of NO3- to N2 under anoxic conditions.

Accepted Answer

A) True 
 B)False

Question 12

Photosynthesis in purple phototrophic bacteria begins when exciton energy strikes the________of bacteriochlorophyll a molecules.

Accepted Answer

The answer of Photosynthesis in purple phototrophic bacteria begins when...

Question 13

An organism that is mixotrophic can switch between being autotrophic and heterotrophic depending on its environment.

Accepted Answer

A) True 
 B)False

Question 14

Aerobic bacteria, which undergo nitrification, iron- , or sulfur- oxidation, all fix CO2 by using the________ cycle.

Accepted Answer

The answer of Aerobic bacteria, which undergo nitrification, iron- ,...

Question 15

A(n)________ is the low light efficiency structure that functions like an antenna and is found in the green sulfur and green nonsulfur bacteria.

Accepted Answer

The answer of A(n)________ is the low light efficiency structure...

Question 16

Bacteria that are capable of oxidizing both iron and sulfur usually have a strong preference for sulfur oxidation because it yields more energy.

Accepted Answer

A) True 
 B)False

Question 17

During oxygenic photosynthesis,

Accepted Answer

A)  oxygen is consumed. 
B)  oxygen functions as a catalyst. 
C)  oxygen is produced. 
D)  none of the above. 
A)  oxygen is consumed. 
B)  oxygen functions as a catalyst. 
C)  oxygen is produced. 
D)  none of the above.

Question 18

Because H2 levels in oxic environments are transient, it is likely that aerobic hydrogen bacteria shift between chemoorganotrophy and chemolithotrophy depending on levels of organic compounds and hydrogen in their habitats.

Accepted Answer

A) True 
 B)False

Question 19

What compound do most chemolithotrophs use as a source of carbon?

Accepted Answer

A)  glucose 
B)  carbon dioxide 
C)  inorganic compounds 
D)  organic sources other than glucose 
A)  glucose 
B)  carbon dioxide 
C)  inorganic compounds 
D)  organic sources other than glucose

Question 20

Most phototrophic organisms are also autotrophs.

Accepted Answer

A) True 
 B)False

Exam 13: Phototrophy, Chemolithotrophy, and Major Biosyntheses

Briefly describe what occurs when elemental sulfur is provided externally as an electron donor and how energy is obtained.

The ammonia switch- off effect is a(n)

Phycobiliproteins form into aggregates called________ that attach to the photosynthetic membranes. Cells with an increased number of these structures can grow at________ (higher/lower) light intensities.

Describe the anammox reaction.

Carotenoids

Light harvesting protein complexes found in cyanobacteria and chloroplasts in red algae are called

H2- oxidizing bacteria are all aerobic.

Photosystems I and II normally function in tandem in oxygenic photosynthesis.

Explain why most iron- oxidizing bacteria are obligately acidophilic, and discuss some of the environments where these organisms are found.

Organisms that obtain energy from the oxidation of an inorganic compound and require an organic compound as a carbon source are known as________ .

Chemotrophic denitrifying bacteria can couple the oxidation of Fe2+ to the reduction of NO3- to N2 under anoxic conditions.

Photosynthesis in purple phototrophic bacteria begins when exciton energy strikes the________of bacteriochlorophyll a molecules.

An organism that is mixotrophic can switch between being autotrophic and heterotrophic depending on its environment.

Aerobic bacteria, which undergo nitrification, iron- , or sulfur- oxidation, all fix CO2 by using the________ cycle.

A(n)________ is the low light efficiency structure that functions like an antenna and is found in the green sulfur and green nonsulfur bacteria.

Bacteria that are capable of oxidizing both iron and sulfur usually have a strong preference for sulfur oxidation because it yields more energy.

During oxygenic photosynthesis,

Because H2 levels in oxic environments are transient, it is likely that aerobic hydrogen bacteria shift between chemoorganotrophy and chemolithotrophy depending on levels of organic compounds and hydrogen in their habitats.

What compound do most chemolithotrophs use as a source of carbon?

Most phototrophic organisms are also autotrophs.

Microorganisms and Microbiology

A Brief Journey to the Microbial World

Cell Structure and Function in Bacteria and Archaea

Nutrition, Culture, and Metabolism of Microorganisms

Microbial Growth

Molecular Biology of Bacteria

Archael and Eukaryotic Molecular Biology

Regulation of Gene Expression

Viruses and Virology

Genetics of Bacteria and Arachaea

Genetic Engineering

Microbial Genomics

Catabolism of Organic Compounds

Commercial Products and Biotechnology

Microbial Evolution and Systematics

Bacteria: the Proteobacteria

Other Bacteria

Archaea

Eukaryotic Cell Biology and Eukaryotic Microorganisms

Viral Diversity

Methods in Microbial Ecology

Major Microbial Habitats and Diversity

Nutrient Cycles, Biodegradation, and Bioremediation

Microbial Symbioses

Microbial Growth Control

Microbial Interactions With Humans

Immunity and Host Defense

Immune Mechanisms

Molecular Immunology

Diagnostic Microbiology and Immunology

Epidemiology

Person-To-Person Microbial Diseases

Vectorborne and Soilborne Microbial Pathogens

Wastewater Treatment, Water Purification, and Waterborne Microbial Diseases

Food Preservation and Foodborne Microbial Diseases

Filters

Phycobiliproteins form into aggregates called that attach to the photosynthetic membranes. Cells with an increased number of these structures can grow at (higher/lower) light intensities.

Chemotrophic denitrifying bacteria can couple the oxidation of Fe²⁺ to the reduction of NO₃- to N₂ under anoxic conditions.