1. 1. DNA, RNA structure
2. Transcription, translation

2. DNA is a double-stranded helix
James Watson and Francis Crick worked out the three-dimensional structure of DNA, based on work by Rosalind Franklin
Figure 10.3A, B

3. DNA and RNA are polymers of nucleotides
DNA is a nucleic acid, made of long chains of nucleotides
Phosphate group
Nitrogenous base
Nitrogenous base (A, G, C, or T)
Sugar
Phosphate group
Nucleotide
Thymine (T)
Sugar (deoxyribose)
DNA nucleotide
Polynucleotide
Sugar-phosphate backbone
Figure 10.2A

4. DNA has four kinds of bases,
Adenine(A), Thymine (T), Cytosine (C), and Guanine (G)
Thymine (T)
Cytosine (C)
Adenine (A)
Guanine (G)
Figure 10.2B

5. Each strand of the double helix is oriented in the opposite direction
Anit-Parellel: means parellel but moving in different directions
5 end
3 end P P P P P P P P
3 end
5 end
Figure 10.5B

6. Nitrogenous base (A, G, C, or U)
RNA is also a nucleic acid
different sugar (ribose)
Uracil instead of Thymine
Still has Adenine, Guanine, Cytosine
Single strand, usually
Nitrogenous base (A, G, C, or U)
Phosphate group
Uracil (U)
Sugar (ribose)
Figure 10.2C, D

7. Types of RNA
Genetic information copied from DNA is transferred to 3 types of RNA:
__________ RNA: mRNA
Copy of information in DNA that is brought to the ribosome and translated into protein by tRNA & rRNA.
__________ RNA: rRNA
Most of the RNA in cells is associated with structures known as ribosomes, the protein factories of the cells.
It is the site of translation where genetic information brought by mRNA is translated into actual proteins.
___________ RNA: tRNA
Brings the amino acid to the ribosome that mRNA coded for.
Messenger
Ribosomal
Transfer
From the Virtual Cell Biology Classroom on ScienceProfOnline.com
Images: Blueprint, clipart; Factory, Andreas Praefcke; Truck, PRA.

8. The information constituting an organism’s genotype is carried in its sequence of bases
The DNA is transcribed into RNA, which is translated into a chain of amino acids
Bases of Central Dogma
DNA
TRANSCRIPTION
RNA
TRANSLATION
Protein
Figure 10.6A

9. Transcription produces mRNA
RNA nucleotide
RNA polymerase
Direction of transcription
Template strand of DNA
Newly made RNA
Figure 10.9A

10. In transcription, DNA helix unzips
RNA polymerase
In transcription, DNA helix unzips
DNA of gene
Promoter
DNA
Terminator
DNA
Initiation
RNA nucleotides line up along one strand of DNA, following the base-pairing rules
single-stranded messenger RNA peels away and DNA strands rejoin
Elongation
Area shown in Figure 10.9A
Termination
Growing RNA
Completed RNA
RNA polymerase
Figure 10.9B

11. RNA transcripts of DNA

12. Translation of mRNA into amino acids
The “words” of the DNA “language” are triplets of bases called codons
The codons in a gene specify the amino acid sequence of a protein
In other words, codons are every 3 bases.

13. Gene 1 Gene 3 Gene 2 Codon Amino acid
DNA molecule
Gene 2
DNA strand
TRANSCRIPTION
RNA
Codon
TRANSLATION
Protein
Amino acid
Figure 10.7

14. An exercise in translating the genetic code
Transcribed strand
DNA
Transcription
RNA
Start codon
Stop codon
Translation
Polypeptide
Figure 10.8B

15. Transfer RNA molecules serve as interpreters during translation
In the cytoplasm, a ribosome attaches to the mRNA and translates its message into a protein
The process is aided by transfer RNAs
Amino acid attachment site
Hydrogen bond
RNA polynucleotide chain
Anticodon
Figure 10.11A

16. Each tRNA molecule has a triplet anti-codon on one end and an amino acid attachment site on the other
Amino acid attachment site
Anticodon
Figure 10.11B, C

17. Ribosomes build chains of amino acids
Next amino acid to be added to protein
Growing protein
tRNA
molecules
P site
A site
Growing protein
Large subunit
tRNA P A
mRNA
mRNA binding site
Codons
mRNA
Small subunit
Figure 10.12A-C

18. An initiation codon marks the start of an mRNA message
AUG = methionine
Start of genetic message
End
Figure 10.13A

19. mRNA, a specific tRNA, and the ribosome subunits assemble during initiation
Large ribosomal subunit
Initiator tRNA
P site
A site
Start codon
Small ribosomal subunit
mRNA 1 2
Figure 10.13B

20. How does translation happen?
The mRNA moves one codon at a time relative to the ribosome
A tRNA pairs with each codon, adding an amino acid to the growing protein
A STOP codon causes the mRNA-ribosome complex to fall apart
This results in a chain of amino acids
Amino Acid (AA) + AA + AA + AA…etc = Protein

21. Transcription RNA RNA polymerase DNA
During transcription, RNA polymerase uses one strand of DNA as a template to assemble nucleotides into a strand of RNA.

22. Translation Lysin e tRNA mRN A Ribosome
During translation, or protein synthesis, the cell uses information from messenger RNA to produce proteins. The cell uses all three main forms of RNA during this process.
mRN A
Translation direction
Ribosome
Copyright Pearson Prentice Hall

23. Complete -Protein Synthesis Worksheet -Book Worksheet
Pause for Worksheet
Complete -Protein Synthesis Worksheet -Book Worksheet

24. What molecules are present in this photo? Red object = ?
Figure: 14-12
Title:
Mass production.
Caption:
a. An mRNA transcript can be translated by many ribosomes at once, resulting in the production of many copies of the same protein. b. A micrograph of this process in operation. The figure shows two mRNA strands with ribosomes spaced along their length. In the upper strand, translation is underway and polypeptides can be seen emerging from the ribosomes.
What molecules are present in this photo?
Red object = ?

25. Table 14.2 Types of RNA Type of RNA Functions in Function
Messenger RNA
(mRNA)
Nucleus,
migrates
to ribosomes
in cytoplasm
Carries DNA
sequence
information to
ribosomes
Transfer RNA
(tRNA)
Cytoplasm
Provides linkage
between mRNA
and amino acids;
transfers amino
acids to ribosomes
Figure: Table 14.2
Title:
Types of RNA.
Caption:
Ribosomal RNA
(rRNA)
Cytoplasm
Structural
component
of ribosomes

26. Review: The flow of genetic information in the cell is DNARNAprotein
The sequence of codons in DNA spells out the primary structure of a protein
A chain of amino acids form proteins that cells and organisms use

27. Overview Eukaryotic Cell ______________
Synthesis of RNA under the direction of DNA (mRNA).
Actual synthesis of a polypeptide (protein) under the direction of mRNA.
Transcription
Translation
From the Virtual Cell Biology Classroom on ScienceProfOnline.com
Diagram: Transcription & Translation, NIH

28. Complete -DNA Molecule & Replication
Pause for Worksheet
Complete -DNA Molecule & Replication

29. So how is DNA read to make Amino acids
We use the Genetic Coding Chart
Virtually all organisms share the same genetic code- the sequence is what is important

30. This is another one Second Base U C A G UUU UCU UAU UGU U phe tyr cys
UCC
UAC
UGC C U
ser
UUA
UCA
UAA
stop
UGA
stop A
leu
UUG
UCG
UAG
stop
UGG
trp G
CUU
CCU
CAU
CGU U
his
CUC
CCC
CAC
CGC C C
leu
pro
arg
CUA
CCA
CAA
CGA A
gln
CUG
CCG
CAG
CGG G
First Base
Third Base
AUU
ACU
AAU
AGU U
asn
ser
AUC
ile
ACC
AAC
AGC C A
thr
AUA
ACA
AAA
AGA A
lys
arg
Figure: 14-07
Title:
The genetic code dictionary.
Caption:
If we know what a given mRNA codon is, how can we find out what amino acid it codes for? This dictionary of the genetic code offers a way. In Figure 14.5, you saw that the codon CGU coded for the amino acid arginine (arg). Looking that up here, C is the first base (go to the C row along the “first base” line), G is the second base (go to the G column under the “second base” line) and U is the third (go to the codon parallel with the U in the “third base” line).
AUG
met (start)
ACG
AAG
AGG G
GUU
GCU
GAU
GGU U
asp
GUC
GCC
GAC
GGC C G
val
ala
gly
GUA
GCA
GAA
GGA A
glu
GUG
GCG
GAG
GGG G

31. Before we begin In DNA A binds with T (like AT&T)
C binds with G (like Cover Girl)
RNA is the same BUT there is no T
It is a U so A and U bind together

32. Create a DNA sequence with 30 bases
Step 1:
Create a DNA sequence with 30 bases
Must start with TAC
Must end with ATT
After that you are good to go with any bases

33. Step 2:
Using your DNA, make a complimentary mRNA strand

34. Step 3: Using your mRNA strand
Start at the beginning and circle every 3 codons

35. Look at your first codon
Step 4:
Look at your first codon
Match the first letter, second letter and third letter to the Genetic Coding Chart.
Write the Amino Acid under the circled codon

36. Continue until all codons are labeled with an amino acid
Step 5:
Continue until all codons are labeled with an amino acid
Now you have a chain of Amino Acids
Also called a PROTEIN

37. Example methionine proline leucine
DNA strand A – T – G – C – C – T – T – T – G
T – A – C – G – G – A – A – A – C
mRNA strand A – U – G – C – C – U – U – U – G
1st codon A-U-G amino acid = methionine
2nd codon C-C-U amino acid = proline
3rd codon U-U-G amino acid = leucine
methionine
proline
leucine

38. Complete the 3 Genetic Coding Worksheets
Pause for Worksheet
Complete the 3 Genetic Coding Worksheets

39. (You must be in PPT slideshow view to click on links.)
Confused?
Here are links to fun resources that further explain genetic transcription & translation:
Molecular Genetics: Transcription & Translation Main Page on the Virtual Cell Biology Classroom of Science Prof Online.
“That Spells DNA” song by Jonathan Coulton.
DNA Transcription step-through animation by John Kyrk.
Transcribe & Translate a Gene, from University of Utah.
DNA Transcription and Protein Assembly animated movie by RedAndBrownPaperBag.
Genetic by Sonic Youth.
Transcription and Translation animated movie from PBS production “DNA: The Secret of Life.
“The Protein Synthesis Song” by MrsPurpleMonster18.
(You must be in PPT slideshow view to click on links.)
Smart Links
From the Virtual Cell Biology Classroom on ScienceProfOnline.com