1. Unit 6
notes:
RnA
&
Protein Synthesis

2. (1) What is RNA?
• RNA = RiboNucleic Acid
• Structure:
– RNA Nucleotide = Phosphate, Ribose Sugar, N.Base
– Types of Nitrogenous Bases:
• Uracil (U) pairs with Adenine (A)
• Guanine (G) pairs with Cytosine (C)
• [U in RNA replaces the T in DNA.]
• Types of RNA:
• Messenger RNA (mRNA)
• Ribosomal RNA (rRNA)
• Transfer RNA (tRNA)

3. (2) Protein Synthesis Basics
• Overall Goal: Use DNA to put together the
correct sequence of amino acids, building a
specific protein molecule.
• Steps:
1- Transcription (DNA  RNA)
2- Translation (RNA  Protein)
• Keep In Mind:
Your genetic code IS the unique order of
nitrogenous bases!

4. (3) Codons & Anticodons
• CODONS:
– Codons are located on Messenger RNA (mRNA).
– 1 Codon = 3 Nitrogenous Bases
– 1 Codon = 1 Amino Acid
• ANTICODONS:
– Anticodons are located on Transfer RNA (tRNA).
– 1 Anticodon = 3 Nitrogenous Bases
– 1 Anticodon = 1 Amino Acid

6. (4) Transcription: DNA  RNA
• Overall Goal: Take the code from DNA nitrogenous
bases and copy it onto an RNA molecule.
• Why??: DNA cannot leave the nucleus. DNA cannot be
directly translated into protein.
• Steps:
1. DNA strands unwound and separated by helicase.
2. The enzyme RNA Polymerase binds to DNA.
3. RNA Polymerase matches up RNA bases with DNA bases.
4. END PRODUCT = 1 Strand of Messenger RNA (mRNA)
5. mRNA leaves the nucleus.
• Keep In Mind:
Only 1 strand of DNA needs to be transcribed since the
bases are complimentary.

7. (5) Transcription Examples:
WHAT WOULD BE THE CORRESPONDING
STRAND OF mRNA?
DNA Template: TAC—GCG—AAA—ACT

8. (6) Translation: RNA  Amino
Acids
• Overall Goal: Take the code from RNA molecule and
translate it into an amino acid chain (protein).
• Why??: DNA and RNA are only instructions. Proteins are
the molecules that actually do things inside cells.
• Steps:
1. mRNA moves through Ribosomal RNA (rRNA) 5’  3’.
2. Begin with the Start Codon, and End with the Stop Codon.
3. mRNA codons are matched up with tRNA anti-codons.
4. Every 1 Codon = 1 Amino Acid brought by Transfer RNA
5. END PRODUCT = 1 Specific Polypeptide (Protein).
• Keep In Mind:
tRNA molecules are floating around waiting to match up
their anticodons to mRNA codons during translation. They
automatically have amino acids ready to go! 

10. (7) Translation Examples:
WHAT WOULD BE THE CORRESPONDING
AMINO ACID SEQUENCE?
mRNA Strand: AUG—CGC—UUU—UGA