Protein Synthesis
Two types of nucleic acids
RNA
DNA
Usually single-stranded
Usually double-stranded
Has uracil as a base
Has thymine as a base
Ribose as the sugar
Deoxyribose as the sugar
Carries protein-encoding
information
Carries RNA-encoding
information
Transcription
RNA polymerase reads the nucleotides on the template
strand from 3’ to 5’ and creates an RNA molecule that
looks like the coding strand.
DNA coding strand
5
’
3’
DNA
GT CA TT CGG
3’
C AG T AAGCC
DNA template strand
5’
Transcription
RNA polymerase reads the nucleotides on the template
strand from 3’ to 5’ and creates an RNA molecule that
looks like the coding strand.
DNA coding strand
5
’
3’
DNA
GT CA TT CGG
3’
C AG T AAGCC
DNA template strand
5’
Transcription
The new RNA molecule is formed by incorporating
nucleotides that are complementary to the template
strand.
DNA coding strand
5
’
3’
DNA
GT CA TT CGG
3’
G UC AUUCG G
3’
C AG T AAGCC
5’
DNA template strand
5
’
RNA
Types of RNA
Abbrev.
Function
mRNA
Messenger RNA
- encodes protein
rRNA
Ribosomal RNA
- part of ribosome
- used to translate
mRNA into protein
tRNA
Transfer RNA
- couples the region
which binds the
mRNA codon and
its amino acid
Translation

The process of reading the RNA sequence of an
mRNA and creating the amino acid sequence of a
protein is called translation.
DNA
template
DNA
Transcription
T
T
C
A
G
T
C
A
G
A
A
G
U
C
A
G
U
C
strand
Messenger
RNA
mRNA
Codon
Codon
Codon
Translation
Protein
Lysine
Serine
Valine
Polypeptide
(amino acid
sequence)

http://www.lewport.wnyric.org/jwanamak
er/animations/Protein%20Synthesis%20%20long.html