Question

For a thermophile, how do their proteins, DNA and cell membrane differ from mesophiles or psychrophiles?

Answer 1

Thermophiles, live in extreme temperature ranging from 42^° c to 140^°c approximately whereas mesophile lives in moderate temperature and psychrophile in extreme cold. Due to higher temparature special adaptations are present in their protein, DNA and cell membrane.Heat shock protein (Hsp), a molecular chaperone, helps thermophile to survive allowing proteins to fold in high temparature and prevent thermal denaturation of already folded proteins. This is a ATP dependent process .

Normally DNA strand is held together via base pairing between adenine and thymine(double bond) & guanine and cytosine(triple bond). DNA of thermophile bacteria are GC rich which allow better stability. More the number of hydrogen bonds more energy is required to break double stranded DNA. Because the environment where thermophiles live high thermal energy is available to breakdown DNA so more GC rich DNA strand is required.

Another adaptation is found in the phospholipid of cell membrane. Higher number of saturated fatty acid and long hydrophobic chain of fatty acid allow to increase thermal melting point (T_m).