2. RNA to Proteins:
Making Proteins
* Be sure to watch Part I about messenger RNA before
continuing with Part II: Making Proteins.
3. A T U
G C C
G C C
T A A
A T U
Original DNA mRNA copy
Now that the mRNA has successfully made a copy of
the DNA’s instructions, it is ready to leave the nucleus
– remember mRNA has permission as the
“messenger” to leave while the DNA does not.
4. U
C
C
U
A
mRNA copy
G
G
A
tRNA
Amino Acid
Now that the mRNA has left the nucleus it is ready to
combine with a ribosome and “transfer” RNA (tRNA)
to make proteins.
5. Ribosome
mRNA
U
C
C
U
A
G
G
C
G
G
A
tRNA #1 tRNA #2
Amino Acid Amino Acid
The ribosome reads the mRNA message and then looks for
the “transfer” RNA (tRNA) carrying the correct message.
Which tRNA is carrying the correct message - #1 or #2?
6. Ribosome
mRNA
U
C
C
U
A
G
G
A tRNA #2
Amino Acid
Answer = tRNA #2
When the ribosome finds the correct tRNA
message, they combine.
7. Ribosome
U
C
C
U
U
A
G
G
U
A
A
A
tRNA tRNA
Amino Acid
Amino Acid
This process then repeats itself. The ribosome moves to the
right and reads the next 3 bases. The correct tRNA matches up
and brings the next amino acid. The first amino acid then sticks
to the first one.
8. Ribosome
U
C
C
U
U
A
G
G
U
A
A
A
tRNA tRNA
Amino Acid
Amino Acid
This process happens over and over again. Once the whole
mRNA message has been read, the amino acid “chain” is
released and becomes a protein.
