The Fermi Paradox - Why we haven't been contacted by aliens

[ThaVirus]

Originally Posted by 'Hamas' Jenkins

If you want some whack shit, consider this: all naturally occurring amino acids on Earth are left-handed, even though there is no real functional advantage for an AA to be right or left-handed. It's just an evolutionary quirk. Meteorites with trace amino acids have been found to have a 50-50 split of right and left handed AA's.

Explain...

['Hamas' Jenkins]

Originally Posted by ThaVirus

Explain...

Certain molecules possess a trait called chirality, or handedness. The chemical formula is the same, but one branch is a mirror image that you can't superimpose on the other molecule (think about your right and left hands). This usually doesn't affect much chemistry, except with other chiral molecules.

For example, you cannot have a peptide chain unless all of the amino acids are of the same handedness, because an S-amino acid won't be able to form a chain of bonds with two D-amino acids (S, sinister, means left and D, dextro, means right). Without those chains, you don't have proteins, thus, no life.

No one knows why this happened. More than likely, it was just a quirk of genetic randomness.

[Canofbier]

Originally Posted by ThaVirus

Explain...

Originally Posted by 'Hamas' Jenkins

Certain molecules possess a trait called chirality, or handedness. The chemical formula is the same, but one branch is a mirror image that you can't superimpose on the other molecule (think about your right and left hands). This usually doesn't affect much chemistry, except with other chiral molecules.

For example, you cannot have a peptide chain unless all of the amino acids are of the same handedness, because an S-amino acid won't be able to form a chain of bonds with two D-amino acids (S, sinister, means left and D, dextro, means right). Without those chains, you don't have proteins, thus, no life.

No one knows why this happened. More than likely, it was just a quirk of genetic randomness.

And maybe it doesn't need to be said, Virus, but the fact that we see those amino acids unlike the ones from Earth implies that life (or at least the building blocks of it) may have existed wherever that meteor originated from.

Whack indeed.

[Kaepernick]

Originally Posted by 'Hamas' Jenkins

Certain molecules possess a trait called chirality, or handedness. The chemical formula is the same, but one branch is a mirror image that you can't superimpose on the other molecule (think about your right and left hands). This usually doesn't affect much chemistry, except with other chiral molecules.

For example, you cannot have a peptide chain unless all of the amino acids are of the same handedness, because an S-amino acid won't be able to form a chain of bonds with two D-amino acids (S, sinister, means left and D, dextro, means right). Without those chains, you don't have proteins, thus, no life.

No one knows why this happened. More than likely, it was just a quirk of genetic randomness.

Egads, you are forcing my mind to recall my Organic Chemistry classes of 35 years ago. I haven't heard sinister and dextro for 35 years.