This document summarizes the three main types of RNA - messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA) - and their roles in protein synthesis. It also briefly discusses the history of RNA discovery, including the discoveries of tRNA, rRNA, and catalytic RNA (ribozymes). Key events included Friedrich Miescher's discovery of nucleic acids in 1868, Severo Ochoa's discovery of how RNA is synthesized winning him the 1959 Nobel Prize, and Robert Holley's determination of the first tRNA sequence winning him the 1968 Nobel Prize.

1. Alan Sotelo
Alberto Quiñonez
Galo Garcia de Leon
Ivan Flores Roman

2.  The major role of RNA is to participate in
protein synthesis, which requires three
classes of RNA:
 Messenger RNA (mRNA)
 Transfer RNA (tRNA)
 Ribosomal RNA (rRNA).

3.  mRNA is transcribed from DNA, carrying
information for protein synthesis.
 the mRNA carries the genetic information
from the nucleus to the site of protein
synthesis (ribosome) in the cytoplasm to be
translated.

4.  Short-chain RNA molecules present in the cell
that attach the correct amino acid to
the protein chain that is being synthesized at
the ribosome of the cell.
 The major role of tRNA is to translate mRNA
sequence into amino acid sequence.
 Consists of 70 to 80 nucleotides.

5.  rRNA molecules are produced in the nucleus,
they are transported to the cytoplasm, where
they combine with tens of specific proteins to
form a ribosome.

6.  Ribozymes are the RNA molecules with
catalytic activity. They were discovered in
early 1980s by Thomas Cech and Sidney
Altman who shared the 1989 Nobel Prize in
Chemistry.

7.  Major types of small RNA molecules:
 Small nuclear RNA (snRNA) - involved in
mRNA splicing.
 Small nucleolar RNA (snoRNA) - directs the
modification of ribosomal RNAs.
 Micro RNA (miRNA) and short interfering RNA
(siRNA) - regulate gene expression.

8.  Nucleic acids were discovered in 1868 by
Friedrich Miescher, who called the material
'nuclein' since it was found in the nucleus.
 It was later discovered that prokaryotic cells,
which do not have a nucleus, also contain
nucleic acids.

9.  The role of RNA in protein synthesis was
suspected already in 1939.
 Severo Ochoa won the 1959 Nobel Prize in
Medicine after he discovered how RNA is
synthesized.

10.  The sequence of the 77 nucleotides of a yeast
tRNA was found by Robert W. Holley in 1965,
winning Holley the 1968 Nobel Prize in
Medicine.

11.  In 1967, Carl Woese realized RNA can be
catalytic and proposed that the earliest forms
of life relied on RNA both to carry genetic
information and to catalyze biochemical
reactions

12.  http://www.biology-
online.org/dictionary/Transfer_rna
 http://www.web-
books.com/MoBio/Free/Ch3C6.htm
 http://www.news-medical.net/health/RNA-
Discovery.aspx