Vesicles Protect Activated Acetic Acid
Open Access
- Author:
- Todd, Zoe Robin
- Area of Honors:
- Astobiology
- Degree:
- Bachelor of Science
- Document Type:
- Thesis
- Thesis Supervisors:
- Christopher Howard House, Thesis Supervisor
Jennifer Macalady, Thesis Honors Advisor - Keywords:
- Methyl thioacetate
origin of life
prebiotic chemistry - Abstract:
- Methyl thioacetate, or activated acetic acid, has been proposed to be central to the origin of life, and also as an important energy currency molecule in early cellular evolution. We have investigated the hydrolysis of methyl thioacetate under various conditions. Its uncatalyzed rate of hydrolysis is about three orders of magnitude faster (K = 0.00663 s-1; 100°C, pH 7.5, concentration = 0.33mM) than published rates for its catalyzed production making it unlikely to accumulate under prebiotic conditions. However, our experiments showed that methyl thioacetate was protected from hydrolysis when inside its own hydrophobic droplets. Further, we found that methyl thioacetate protection from hydrolysis was also possible in droplets of hexane and in the membranes of nonanoic acid vesicles. Thus, the hydrophobic regions of prebiotic vesicles and early cell membranes could have offered a refuge for this energetic molecule, increasing its lifetime in close proximity to the reactions for which it would be needed. This model of early energy storage evokes an additional critical function for the earliest cell membranes.