Lecture 15-16

Question 1

What are Thylakoids?

Answer 1

Specialist systems in only Gram-negative phototrophs (ex. cyanobacteria) that maximize the photosynthetic capability of the cell

Question 2

What are Carboxysomes?

Answer 2

Specialized protein microcompartments found in Gram-negative cells that fix CO2 using enzymes (ex. cyanobacteria)

Question 3

What are Gas Vesicles?

Answer 3

Hollow proteins tubes that allow microbes to float by maintaining a set buoyancy (ex. Microcystis algal blooms)

Question 4

What are the applications of cyanobacteria in real life?

Answer 4

1) The colour of flamingoes are from a cyanobacteria diet
2) Cyanobacteria produce highly potent toxins
3) Used as a dietary supplement and food source
4) Used in the production of eco-friendly renewable biodiesel/fuels

Question 5

What are the classification parameters of microorganisms based on temperature?

Answer 5

1) Hyperthermophiles - Above 80°C
2) Thermophiles - Between 50-80°C
3) Mesophiles - Between 15-45°C
4) Psychrophiles - Below 15°C

Question 6

What are the classification parameters of microorganisms based on pH?

Answer 6

1) Alkaliphiles - Above pH 9
2) Neutralophiles - Between pH 5-8
3) Acidophiles - Below pH 3

Question 7

What are the classification parameters of microorganisms based on osmolarity?

Answer 7

1) Halophiles - Live in only high salt concentrations (require above 2 M of NaCl to survive)
2) Halotolerant - Can live in both high and low concentrations of salt (Can grow up to 2 M NaCl)

Question 8

What are the classification parameters of microorganisms based on oxygen use?

Answer 8

1) Strict Aerobe - Can only live and reproduce with oxygen
2) Facultative Microbe - Can live and reproduce with and without oxygen
3) Microaerophile -Can live and reproduce with only very small levels of oxygen
4) Strict Anaerobe - Can only live and reproduce without oxygen

Question 9

What are the classification parameters of microorganisms based on pressure?

Answer 9

1) Barophiles - Exist at pressures greater than 380 atm
2) Barotolerant - Exist at pressures between 10-500 atm

Question 10

The domain Bacteria is considered the best studied Phyla. What are the different Phyla under this domain?

Answer 10

1) Oxygenic Phototrophs - Cyanobacteria
2) Gram-Positive - Firmicutes and Actinobacteria
3) Gram-Negative - Proteobacteria, Spirochetes, Bacteroidetes, and PVC Superphylum

Question 11

What are the characteristics of cyanobacteria?

Answer 11

1) Oxygenic photoautotrophic prokaryotes (produce oxygen)
2) Contain chlorophyll and other pigments

Question 12

What are the characteristics of Proteobacteria?

Answer 12

1) Divided into 5 major classes - Alpha-, beta-, gamma-, delta-, epsilon-
2) Contain a triple-layered Gram-negative cell envelope
3) Have a diverse metabolism
4) Have diverse lifestyles

Question 13

True or False: Alphaproteobacteria are endosymbionts - Nitrogen fixers and plant roots (ex. Rhizobium)

Answer 13

True

Question 14

True or False: Betaproteobacteria include many species that are pathogenic to humans and animals

Answer 14

False: It is Gammaproteobacteria that contain several pathogenic species.

Question 15

What are the characteristics of Bacteroidetes?

Answer 15

1) Non-spore forming
2) Gram-negative
3) Contain aerobic and anaerobic species
4) Can be opportunistic pathogens (beneficial more often than not) to humans
5) Breaks down toxins in food

Question 16

What are the Characteristics of Firmicutes?

Answer 16

1) Consists of large rod-shaped cells
2) Low-GC species
3) Bacillus and Clostridium species are able to form endospores (Staphylococcus and Streptococcus are non-spore forming)

Question 17

True or False: Actinobacteria are low-GC species

Answer 17

False: They are high-GC species

Question 18

Archaea contain many phyla. What is the most divergent phylum in Archaea?

Answer 18

Euryarchaeota

Question 19

What are methanogens and what are their function?

Answer 19

They are made of pseudopeptidoglycan (most commonly), sulfated polysaccharides, or S-layer proteins. They produce methane that is trapped under oceans of permafrost deep underground.

Question 20

What are the characteristics of Euryarchaeota?

Answer 20

1) Contain several polyphyletic clades of methanogens
2) Serve as a key energetic role for anaerobic removal of H2 and other reductants
3) Inhabit diverse environments

Question 21

What are the charactersitics of Pyrococcus furiosus?

Answer 21

1) Live in deep-sea hydrothermal vents
2) Hyperthermophiles and barophiles
3) Thrives in 100°C conditions
4) Can metabolize sulfur into sulfuric acid (H2S)
5) An anaerobe

Question 22

What are the uses of Archaea in Biotechnology?

Answer 22

1) Creating extremozymes - Enzymes with novel ranges in stability
2) Making vaccine adjuvants - An ingredient used to create a stronger immune response
3) Potential source of antibiotic classes being researched by the pharmaceutical industry