Page 238 - The Manga Guide to Biochemistry

Another type of RNA, which transports amino acids, is called transfer RNA
(tRNA). The tRNA matches the base sequences of the delivered mRNA with
the amino acids needed to build the coded proteins.

It should be pretty obvious where transfer RNA gets its name: it transfers
amino acids.

The mRNA base sequence is a code for an amino acid sequence. More specifi-
cally, a three-base sequence forms the code for one amino acid. This three-
base sequence is called a codon.

codon codon codon

AU GA C AU GU

There are unique tRNA molecules for each codon. In other words, only a tRNA
with the proper base sequence—called an anticodon—that is complementary to
the mRNA’s codon can adhere at the site of the ribosome.*

The role of rRNA is to connect the amino acids that were transported via
tRNA into long chains. Amino acids are connected according to the mRNA base
sequence (that is, the codon sequence) to create proteins in accordance with
the base sequence (the genes, or “blueprint”) of the original DNA.

tRNA

Ribosome (rRNA) Amino
acid

Anticodon
Codon

mRNA mRNA

So in other words, genetic information is conveyed like this: DNA  RNA 
protein.

* The type of amino acid that is transported is also determined by the anticodon.
224 Chapter 5