BioSignatures Flashcards
1
Q
Definition
A
- physical or chemical substances, objects, patterns indicate presence/past presence of life
- any characteristic element, molecule, substance, or feature that can be used as evidence of past/present life and is distinct from and a biogenic process
- search for habitability/CHNOPS
2
Q
Lipid Biosignatures
A
- isoprenoids - synthesis of larger biomolecules
- hopranes - used in cell membranes in bacteria
- sterols - signalling, cell membranes in eukaryotes
3
Q
Can be difficult to distinguish….
A
from abiotic processes
ex: Methane on Mars
- product of biological or abiotic processes?
4
Q
Gaseous Biosignatures
A
- strongest biosignature = oxidizing + reducing gas
- EARTH: O2/O3 + CH4
CH4 - methane - volcanoes, water/rock itneractions, decay
O2/O3 - not just biotic, also: UV, H2O, CO2
