Wednesday, November 21, 2007
coisas que eu descubro através do maradona
A simple example involves chirality. Large biological molecules possess a definite handedness: although the atoms in a molecule can be configured into two mirror-image orientations—left-handed or right-handed—molecules must possess compatible chirality to assemble into more complex structures. In known life-forms, the amino acids—the building blocks of proteins—are left-handed, whereas the sugars are right-handed and DNA is a right-handed double helix. The laws of chemistry, however, are blind to left and right, so if life started again from scratch, there would be a 50–50 chance that its building blocks would be molecules of the opposite handedness. Shadow life could in principle be biochemically almost identical to known life but made of mirror-image molecules. Such mirror life would not compete directly with known life, nor could the two forms swap genes, because the relevant molecules would not be interchangeable.
No comments:
Post a Comment
Newer Post
Older Post
Home
Subscribe to:
Post Comments (Atom)
No comments:
Post a Comment