Download Translation Question from Text and Decoding Practice

Date _____
Translation Practice
Name _____________
Dear AP Biology Students:
Good afternoon! Your mission today is to delve into chapter 17, in particular section
17.4 to examine the part of protein synthesis called translation (use the maroon
textbooks at the back right corner of the room). Please answer the questions below and
examine diagrams where included or referenced (remember . . . a picture is worth a
thousand words).
1. Section 17. 4 starts out with a discussion of tRNA. Please address the following:
a. What makes one tRNA different from another?
b. tRNA is a translator because it can read a ________ _____ word and
interpret it as a ____________ word.
c. tRNA has an approximately “L” shaped structure (as seen in the threedimensional model below). What are the two main functional areas of the
tRNA?
Secondly, your text states that the structure of tRNA serves its’ function. How
is this so?
Note that there are many models for tRNA, my yellow “Santa Hat” model at
the back of the room is another. The two dimensional “cloverleaf” model in
figure 17.4 part a is yet another.
2. Although you may not have thought about this particular point before, how does
an amino acid (AA) become attached to a tRNA in the first place? Notice there
are no AA’s attached to the two tRNAs in the figure above.
Date _____
Translation Practice
Name _____________
a. Examine figure 17.15 in your text (you should have the text out by now). Ah,
a special protein that functions as an enzyme called
___________________________________ tirelessly works to attach amino
acids to tRNAs.
b. How many tRNA synthetases exist and why are there exactly that number?
c. What energy molecule is associated with the covalent bonding of amino acids
to the tRNA? Briefly explain how amino acid attachment to tRNAs is an
example of energy coupling.
3. Ribosomes (rRNA). Ribosomes have two subunits a small and large. Ribosomes
also have three binding sites for tRNA on the large subunit: E site, P site, and A
site. Lastly, ribosomes have an mRNA binding site on the small subunit. Please
label diagram 17.16 below.
a. List the functions of the E, P, and A sites.
Date _____
Translation Practice
Name _____________
b. Read the closing paragraph at the bottom of page 339. Why are differences
between prokaryotic and eukaryotic ribosomes medically significant?
c. On pages 340-341 the three main stages (initiation, elongation and
termination) of translation are detailed. Each of these stages is also shown in
diagrams 17.17, 17.18 and 17.19.
Use the figures to summarize the key parts of each stage in the space below:
For example:
Initiation – mRNA binds to the small ribosomal subunit, the start codon AUG
binds with an initiator tRNA having anticodon UAC and amino acid Met. Next
GTP is used to assemble the large subunit onto the small subunit and associated
mRNA. The initiator tRNA is in the P site and the A site is open to receive the
next tRNA that matches the next mRNA codon.
Elongation –
Termination -
Date _____
Translation Practice
Name _____________
Part 1: Use the genetic code below to complete the table.
1
2
3
4
5
6
7
8
9
10
11
12
13
DNA
Sequence
mRNA
Codon
TRNA
Anticodon
Amino Acid
TAC
TTA
CCG
AAA
AUG
UAC
Methionine
CCG
CCU
GTC
GUA
AUA
Tryptophan (Trp)
TGT
UAG
ATT
A
B
C
D
Questions:
1. Moving from column A to column
B is equivalent to what process?
2. Moving from column B to column
D is equivalent to what process?
3. Where does transcription take
place?
4. Where does translation take place?
5. How many bases are needed to code
for one amino acid?
6. How many different codon
combinations are possible?
7. How many amino acids are there?
8.
List all of the codons that code for Proline (Pro)?
9.
What has been created when all of the substances listed in column D have been bonded together?