One end of the tRNA contains an anticodon loop which pairs with a mRNA specifying a certain amino acid. The other end of the tRNA has the amino acid attached to the 3' OH group via an ester linkage. tRNA with an attached amino acid is said to be charged.The enzyme that attaches the amino acid to the 3'-OH is called an aminoacyl tRNA synthetase (aaRS). There is a specific tRNA for each amino acid, 20 in all.Similarly, there is a specific aaRS for each tRNA.ne end of the tRNA contains an anticodon loop which pairs with a mRNA specifying a certain amino acid. The other end of the tRNA has the amino acid attached to the 3' OH group via an ester linkage. tRNA with an attached amino acid is said to be charged.
A convex elliptical mirror will reflect light directed towards one focus as if it were radiating from the other focus, both of which are behind the mirror. A convex hyperbolic mirror will reflect rays emanating from the focal point in front of the mirror as if they were emanating from the focal point behind the mirror.
For a spherically curved mirror in air, the magnitude of the focal length is equal to the radius of curvature of the mirror divided by two. The focal length is positive for a concave mirror, and negative for a convex mirror.In the sign convention used in optical design, a concave mirror has negative radius of curvature, so.he focal length of a lens determines the magnification at which it images distant objects. It is equal to the distance between the image plane and a pinhole that images distant objects the same size as the lens in question.