Extremophile

Question 1

Extremeophile

Answer 1

• single celled Archaea or Bacteria
• extremes: temperature, pH, salinity, pressure, O2 levels
• Ex: tardigrade

Question 2

Thermophiles

Answer 2

• high temperatures
• eukaryotes <50 C
• prokaryotes <60 C
• use proteins and enzymes that are more stable at high temperatures
• higher proportions of G-C nucleobase - more stable at high temperatures
• changes cell membrane composition to reduce membrane fluidity and retain integrity

Question 3

Hyperthermophiles

Answer 3

80-115 C
- may be found in hot springs and ocean vents
- high temp difficult: denaturing of DNA/proteins

Question 4

Psychrophiles

Answer 4

• all major taxa inhabiting cold temperatures
• water is solvent of life, if intracellular water freezes - game over

Question 5

Hypersaline Environments

Answer 5

Osmoprotectant
- neutral charge
- low toxicity
- ex: amino acids

Question 6

Acidophiles

Answer 6

Chemotrophs
- some metabolic reactions are most efficient at low pH
(a) iron reduction and oxidation

Question 7

HIGH pH

Answer 7

Alkaliphile

Question 8

LOW pH

Answer 8

Acidophile

Question 9

HIGH Temp

Answer 9

Thermophile

Question 10

LOW Temp

Answer 10

Psychrophile

Question 11

HIGH Salinity

Answer 11

Halophile

Question 12

LOW WATER/Desiccation

Answer 12

xerophile

Question 13

Relevance of Extremophiles

Answer 13

define boundaries of life
- compare to ET extreme environments/conditions