Name ________________________________________________________ Pd. ___________ # __________
Like DNA, ribonucleic acid (RNA) is a ________________ acid—a molecule made of nucleotides linked together.
RNA differs from DNA in three ways. First, RNA consists of a __________________ strand of nucleotides instead of the two strands found in DNA. Second, RNA nucleotides contain the five-carbon sugar ________________ rather than the sugar deoxyribose found in DNA nucleotides. And third, RNA has a nitrogen base called ________________
(abbreviated as U) instead of the base ________________ (T) found in DNA. No thymine (T) bases are found in RNA.
Like thymine, uracil is complementary to ________________ whenever RNA base-pairs with another nucleic acid.
a-Define the following processes:
-Replication
-Transcription b-Comparing the two processes. Think about this, and try to give 2 items for each box:
How are these two processes SIMILAR How are these two processes DIFFERENT?
Decide if each statement describes DNA only, RNA only, both, or neither. Then check the appropriate column or columns (or neither!) l is a nucleic acid a made of nucleotides
b single strand of nucleotides c double helix d contains amino acids m contains a base that pairs with adenine n used as a template for making nucleic acid o used in transcription e contains uracil p used in replication f contains thymine q used in translation g contains adenine r does not leave the nucleus h contains sugar s leaves the nucleus i contains deoxyribose t has more than one form j contains ribose k contains phosphate

•Where within the cell does each of the following occur? a-replication? ____________________________
•Transcribe mRNA from the following DNA segments: a-CTCCGAT
b-transcription? ____________________________ c-translation? ____________________________

In transcription, RNA polymerase splits the two halves of a strand of DNA. RNA then uses one half as a template to make a copy of the other half. RNA contains the nucleotide uracil instead of the nucleotide thymine.
Label the DNA and
RNA. Then, label the missing nucleotides marked on the diagram.

•Label the following items:
-RNA polymerase
-DNA coding strand
-DNA non-coding strand
-mRNA
a-Label these 3 types of RNA molecules

b-Circle the molecule in charge of bringing amino acids to the ribosome. c-Put an X on the molecule that represents a temporary copy of DNA.
a-Groups of _____ nitrogen bases are translated into amino acids. These trios bases are called _____________________ , and they are located on ___ RNA molecules. Amino acids are the building blocks of ________________________ .

•Review: 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 (protein).
•The Diagram: Below is a strand of mRNA that needs to be translated into protein, and the 4 tRNA’s that will match up with it.
a-Below the four tRNA anticodons, write the numbers 1-4 to show the order in which they would appear to match the codons in the mRNA strand. b-Below the mRNA, identify which amino acid would be brought to make the protein. (Be Careful! Before you do this, make sure to read the TITLE of the table in the notes.)
•First, locate these 2 items and label them:
A-mRNA segment leaving the nucleus
B-mRNA segment at the ribosome
•Then label the following items:
C-tRNA
D-ribosome
E-a codon
F-an anticodon
G-use the table to identify the three specific amino acids on the 3 tRNA’s)
H-nucleus a-Order of tRNA’s
 b-Amino acids:
a-With codons being 3 bases long, there are _________ different combinations. Since there are only _______ amino acids, there is quite enough for each amino acid to have its own “word” to stand for it. b-If you discovered a planet whose residents had 2-base codons, what is the maximum number of amino acids they could use?
(Forget about stop codons for now.) ______ c-Let’s say these aliens had only 2-base codons, but they also had a 5 th base (let’s call it Biligine). THEN how many amino acids could they accommodate? (Forget about stop codons again.) __________

a-Identify the process responsible by writing its name in column B. b-Complete column C by writing the mRNA nitrogen bases that would match up with the DNA bases in column A. Because you’re making RNA, you should use the letters A, U, C & G. c-Identify the process responsible by writing its name in column D. d-Complete column E by writing the correct bases for the tRNA anticodon that bonds to each codon from column C. e-Complete column F by writing the name of the correct amino acid that is coded by each base sequence. Use the table in your notes to translate the mRNA (not tRNA!!) base sequences to amino acids for column F.
A
DNA (base sequence)
Name of the process of converting from
DNA

mRNA
Label this diagram using the word bank:
Nucleus
Cytoplasm mRNA leaving through Nuclear
Pore
DNA
DNA unzipping mRNA (label 2x)
Transcription
Growing Protein tRNA individual Amino
Acids
Ribosome
Name of the process of converting from mRNA

protein

Complete the table below showing sequences of DNA, mRNA codons, anticodons, and corresponding amino acids. Use the list of mRNA codons in the table in your notes to help you complete this exercise. Remember that the genetic code is based on mRNA codons . Some have been done for you.
DNA GAT mRNA codon
Anticodon UUC
UAU
Amino Acid Tryptophan (trp)
a-Describe the structure of the tRNA molecule. Label its anticodon, too

______________________________________________________________________________________________________
______________________________________________________________________________________________________
_____________________________________________________________________________________________ b-Explain why specific base-paring is essential to the processes of transcription and translation.
______________________________________________________________________________________________________
______________________________________________________________________________________________________
______________________________________________________________________________________________________
__________________________________________________________________________________________ c-The structure (shape) and function (job) of a protein is determined by its sequence of what?
Label the following items on the diagram: a-tRNA b-amino acids attached to a tRNA c-ribosome d-growing protein chain e-mRNA f-a codon g-an anticodon h-free-floating amino acids i-a tRNA that has just given up its amino acid and hasn’t replaced it yet j-peptide bond (pick one)
*What process is shown here?
________________________________________

•ABOVE THE ARROWS each of these diagrams shows a strand of normal DNA, plus the strand of mRNA transcribed from it, and the protein strand made from that.
•BELOW THE ARROWS, a slightly mutated piece of
DNA is shown, along with the corresponding mRNA and protein strands.
•Label which of the 3 examples represents which types of mutations

A-substitution
B-insertion
C-deletion
a-Determine how the mutations below will affect each amino acid sequence. Use your translation chart to complete this table. In the space provided, write the names of the amino acids that correspond to each mRNA sequence and mutation given. An example is provided for you. e.g. original UGU- CCG a mRNA Sequence Amino Acid sequence mutated UGC-CGC original GAA-CGU cysteine-proline cysteine-arginine b-What kind of mutation occurred to the mRNA sequence in item d?
Explain. b c d mutated GAU-CGU original AUC-UGC mutated AUC-UGG original UGU-CCU-CCU mutated UGU-UUC-CCU original GGG-UUA-ACC mutated GGU-UAA-CC