 Ribonucleic
Acid
 Macromolecule made of nucleotides from
DNA
 Used to build proteins
 Made in nucleus
 3 types total
RNA:
1.
2.
3.
4.
Single stranded
Uracil instead of Thymine
Ribose instead of
deoxyribose
Can leave the nucleus
1. mRNA = messenger
RNA
 Long and stringy (like
a snake)
 Carries instructions
from the nucleus to the
cytoplasm to initiate
translation
 Contains 3-base
sequences called
“codons”
 Made in transcription
2.
tRNA = transfer RNA
 Shaped like a “T”
 Responsible for bringing the amino acids for
translation
 Contains “anti-codons” that match up with mRNA
temporarily
3. rRNA = ribosomal RNA
 Structurally part of the ribosome organelle
 Site of translation
 Globular shaped

Making of RNA from DNA in the nucleus
1. Initiation at the promoter site, RNA polymerase
opens up the DNA molecule
2. Elongation adds new RNA bases, including
Uracil, down the exposed DNA bases
3. Termination occurs when RNA polymerase hits
the “stop” signal and detaches the new single
strand of RNA
 Transcription
• Unzip one gene in DNA
• Match up bases to one side
of a gene in DNA
• mRNA detaches from the
DNA
• mRNA moves out of the
nucleus and into the
cytoplasm
http://www.concord.org/~btinker/workbe
nch_web/models/eukTranscription.swf
DNA: GAG AAC TAG TAC
RNA:
CUC UUG AUC AUG
 http://www.stolaf.edu/people/giannini/fl
ashanimat/molgenetics/transcription.swf
 How
is Transcription similar to DNA
replication?
 How
is Transcription different from DNA
replication?
1.
Create a Venn diagram comparing and
contrasting DNA and RNA.
2.
How is DNA replication different from
Transcription?
• Consider the steps, enzymes, end result,…
3.
Describe the process of Transcription.