Extremophiles (Week 6)

Question 1

What is an extremophile

Answer 1

• bacteria and archaea
• most are single celled
• micro-organisms that are capable of different degrees of adaptability to the extreme conditions available on earth

Question 2

what are factors used to describe the environment

Answer 2

z temperature
salinity
pressure
PH
oxygen levels

Question 3

Thermophile dump

Answer 3

• dominated by bacteria and archaea
• multi cellular eukaryotes less than 50 and single celled less than 60
• hyperthermophiles- 80-115 may be found in hotsprings and ocean vents
• methanogen methanopyrus thrives at these hot temperatures

Question 4

what are the adaptations that hyper/ thermophiles

Answer 4

• denaturing of DNA and proteins is prevented by using proteins and enzymes stable at higher temps
• cell membrane integrity- change composition to reduce membrane fluidity and retain integrity

Question 5

what’s the earliest extremophile

Answer 5

• LUCA= thermophilic chemolithotroph

Question 6

what are psychrophiles

Answer 6

• represents all major taxa who inhabit temps less than 0

Question 7

what are the psychrophiles adaptations

Answer 7

• decrease in fluidity of the cell mebrane
• by changing the proportions of unsaturated to saturated fatty acids to increase the flexibility
• intracellular water freezing- ‘anti freeze’ molecules and increased salts and sugars
• intracellular water freezing
• depresses freezing point of intracellular water and protects the cell when thawing

Question 8

what are halophile adaptations

Answer 8

• only one- sodium potassium pump
  -stabalises, pressure control and prevents water from escaping

Question 9

what is an adaptation that halophiles go through in extreme environments

Answer 9

• osmoprotectants
• low toxicity and charge and allows na+ ions to be excluded

Question 10

example of halotolerant organisms

Answer 10

stromatalites

Question 11

why are extremophiles important in astrobiology

Answer 11

• help us to understand the constraints for life
• hostile environments such as other places in the solar system
• acidic hot spring on early mars
• sub surface europa

Question 12

what are the features of acidophiles

Answer 12

• chemotrophs
• metabolic reactions efficient at low PH
• ## iron reduction/oxidation

Question 13

acido/alkaliphine adaptations

Answer 13

• need to form a ph gradient to maintain it