Amino racemization dating dating adults net tour index
Since ( ) and () are experimental parameters, the absolute configuration of atoms in chiral molecules are commonly described using R and S, from the Latin rectus (right-handed) and sinistrus (left-handed).An older convention, commonly used by biochemists to describe amino acids and sugars, uses the letters D and L to designate absolute configuration (Figure 1).The first layer is completely formed while the animal is still in the womb, and then becomes biologically inactive (Figure 2). Similar to the rings on a tree trunk, the lens of a whales eye is composed of concentric spheres of protein, with the oldest rings nearest the center.
With these measurements, scientists can estimate the rate at which one enantiomer is converted to the other.
For example, at neutral p H, rates of aspartic acid racemization and DNA depurination are almost identical at temperatures from 45 to 120 °C.
Bada and his colleagues examined the degree of race mization of aspartic acid in archaeological and paleontological samples.
By conducting aspartic acid racemization measurements using an HPLC/fluorescence detection method, Bada analyzed the bowheads eye lenses to estimate the whales age at the time of death (2).
The eye lens of a bowhead whale is made up of dozens of layers of protein, much like an onion.