Extreme Environment

Question 1

Extreme environment

Answer 1

Environment is defined as extreme if the environmental conditions are at one of the two extremes (high/low). These include ➢ i. pH ii. Temperature iii. Salinity iv.Pressure v. Nutrients

Question 2

Extremophiles

Answer 2

Term applied to an organism that has successfully adapted to environments where it is difficult or impossible for other organisms to survive.

Question 3

Thermophiles and hypothermophiles

Answer 3

Organisms with growth temperature optimum between 45ºC and 80ºC are called thermophiles, and those with optimum greater than 80°C are called hyperthermophiles.

Question 4

Halophiles

Answer 4

Some microorganisms (halophiles) have evolved to grow best at reduced water potential, and some (extreme halophiles) even require high levels of salts for growth.

Question 5

Halotolerant

Answer 5

Halotolerant organisms can tolerate some reduction in the water activity of their environment but generally grow best in the absence of the added solute.

Question 6

Acidophiles

Answer 6

Survive by modification of membrane structure. The acidophiles maintain a neutral cytoplasmic pH by actively transporting H+ ions out of the cell.

Question 7

Barophiles and Psychrophillic

Answer 7

Barophiles tolerant to >1000 bar pressure. Also psychrophilic survive at low temp. Live in depth adapted to darkness. They have long chain polyunsaturated fatty acids in their membranes