Download Decoding mRNA

Types of RNA
Name_________________________
Three types of RNA are involved in the process of protein synthesis. Each molecule has specific responsibilities.
Identify the 3
different types of
RNA in Figure 1.
Also indicate by
circling the correct
answer where in the
cell that type of RNA
can be found.
Figure 1
1.________________
(nucleus/cytoplasm)
2. ________________
(nucleus/cytoplasm)
3. ________________
(nucleus/cytoplasm)
Transcription
Transcription occurs in the 4. ______________________ of the cell. It is the process of creating a copy of the
DNA. This copy is called 5. _________________________ and can leave the cell’s nucleus. It travels to the
6.___________________ in the cytoplasm of the cell where DNA’s message can be decoded into a sequence
of amino acids.
The steps of creating an mRNA transcript need to be put in order.
7. Place the numbers 1-5 next to the descriptions of the steps to create an appropriately numbered sequence.
_____ RNA polymerase binds.
_____ The mRNA goes to the ribosome.
_____ DNA unwinds and the double strands are separated.
_____ The RNA transcript separates from DNA.
_____ Complementary nucleotides of RNA are hydrogen bonded to DNA.
Decoding mRNA
Figure 2 shows the mRNA codes that correspond to amino
acids and stop codons. Read from the center outwards. For
example, the mRNA code UAC corresponds to the amino
acid tyrosine.
8. Write the name of the amino acid that corresponds to
each mRNA code. The first one has been done for you.
mRNA Code
Amino Acid
AAA
GCG
GAU
CAA
lysine
Use Figure 2 to answer the questions.
9. Which two mRNA codes correspond to histidine? ____________________
10. How many different mRNA codes correspond to arginine? _________________
Figure 2
Translation
During translation, transfer RNA (tRNA) anticodons match to
messenger RNA (mRNA) codons. Each tRNA molecule can carry
one particular amino acid. The amino acids are joined to form a
polypeptide.
Figure 3
11. Number the four tRNA anticodons in Figure 3 in the order in
which they should appear to match the codons in the
mRNA strand.
Use Figure 3 to answer the question.
12. List the amino acids in the order they would appear in the
polypeptide coded for by the mRNA.
_____________________________________
Figure 4
Figure 4 shows the message from the nucleus
being delivered to the cytoplasm for
translation.
13. Match the terms to the items in the Figure 4:
_____codon
_____anticodon
_____ribosome
_____rRNA
_____tRNA
_____mRNA (2 answers)
_____nucleus
In Figure 5, 14.______ and 15.______ indicate
the two strands of DNA. Use strand A as
the TEMPLATE strand to get the mRNA.
16. Write in the mRNA into D.
17. Use Figure 2 to decode the mRNA
into an amino acid sequence.
18. What is indicated by letters E and F?
_________________________
19. What process is indicated at X?
_________________________
20. What process is indicated at Y?
_________________________
Figure 5