Write the COMPLEMENTARY
DNA strand for each sequence.
1. TACGGCAAACTTACT
2. TACGCCATT
3. TACAAAAAGTGGATC
DNA Replication Review
• Flash Tutorial
Learning Targets
“I Can. . .”
-List three ways that RNA is different from
DNA.
-List the three types of RNA.
-Describe the role of mRNA and tRNA
during protein synthesis.
-Define “transcription” and where it occurs in
the eukaryotic cell.
-Define “translation” and where it occurs in
the eukaryotic cell.
Protein Synthesis
DNA  RNA  Protein
What is RNA? Ribonucleic Acid
1. Nucleotides
A
G
C
U
ADENINE
GUANINE
CYTOSINE
URACIL
What is RNA? Ribonucleic Acid
2. Contains the sugar ribose, rather than
deoxyribose
3. Is single stranded, rather than double
stranded
4. Three types:
a. mRNA (Messenger)
b. tRNA (Transfer)
c. rRNA (Ribosomal)
Why do we have protein in our
bodies?
1.
2.
3.
4.
Enzymes
Major component of the cell membrane
Structural component of skin and muscle
Basically, DNA codes for protein, which
become you!
Recall: DNA is made of nucleotides strung
together into a chain. These
nucleotides code for amino acids.
1. Amino acids: the subunits strung together in
a protein chain
2. The four nucleotides are grouped into
threes: these groups of three are called
codons.
Recall: DNA is made of nucleotides strung
together into a chain. These nucleotides
code for amino acids.
3. Each codon specifies a particular amino acid
that is to be placed in the protein
PAGE 367
AAA = _________________
GGA = _________________
AUG = _________________
UAA = _________________
DNA RNA (Transcription)
1. Transcription: a molecule of DNA is
copied into an opposite strand of
mRNA
*Transcription occurs because DNA
cannot leave the nucleus, and proteins
are made outside the nucleus
DNA RNA (Transcription)
DNA RNA (Transcription)
2. Steps:
a. DNA strands are separated by an
enzyme
b. An mRNA strand is created from the
DNA strand to be copied (remember basepairing rules except . . . )
*G with C
*A with U
DNA RNA (Transcription)
DNA =
mRNA =
TACCGTTGCAACATT
RNA Protein (Translation)
RNA  Protein (Translation)
1. Translation: the creation of a chain of
amino acids from mRNA
mRNA =
AUGGCAACGUUGUAA
Amino acids =
RNA  Protein (Translation)
2. Translation requires tRNA, which
carries amino acids and rRNA, which
makes ribosomes
3. Ribosomes floating in the cytoplasm
and attached to the ER are the location
of protein translation
Alleles for diseases come from
mutations
Mutations: mistakes made during DNA replication
or protein synthesis
1. Nucleotide substitution: TATGCA becomes
TATTCA
2. Nucleotide addition: TATGCA becomes
TATGGCA
3. Nucleotide deletion: TATGCA becomes
TATCA
All produce frameshift mutations!
RNA  Protein (Translation)
1.
DNA
mRNA
Protein
TACGGCAAACTTACT
RNA  Protein (Translation)
2.
DNA
mRNA
Protein
TACGCCATT
RNA  Protein (Translation)
3.
DNA
mRNA
Protein
TACAAAAAGTGGATC
References
• http://www.safarikscience.org/biologyhome
/7_dna/codon_question.png
• http://www.accessexcellence.org/AE/AEP
C/WWC/1994/codon_bingo.php