What is diglycerol tetraether?

Answer 1

It is one of the molecules that build up the cellular membranes of archea. They span the whole membrane from inside out (in contrast to normal cell membranes where each phospholipid spans only "half" the membrane) which is probably one reason why archea are generally more tolerant against high temperatures.

Answer 2

Diglycerol tetraether (GDGT) is a membrane lipid found in archaea. It consists of two glycerol units linked by two ethers and is often used as a biomarker for studying ancient environments through sedimentary records due to its stability. GDGTs have shown promise in paleoclimate reconstructions and can provide information on past temperatures and pH levels.