1. Cell Division and Gene Expression
The Need for Cell Reproduction
- The Nature of Chromosomes
- The Cell Cycle
- Mitosis and Cytokinesis
- Cancer Cells: Abnormal Cell Cycle
The Expression of Genes as Proteins: DNA gene --> RNA --> Protein
- Transcription by RNA Polymerase (DNA gene --> mRNA)
- The Three Types of RNA
- Translation by Ribosome 1

2. Transcription
RNA polymerase
Enzyme that oversees synthesis of mRNA
Unwinds DNA template
Adds complementary RNA nucleotides on DNA template and joins them together
Stops when it reaches termination signal
mRNA pulls off the DNA template, is further processed by enzymes, and enters cytosol

3. Transcription: From DNA to RNA
In transcription,
Genetic information is transferred from DNA to RNA (an RNA molecule is transcribed from a DNA template)
GCAAATGCTGGCCGGAATCTAGGACTGC
CGTTTACGA CCGGCCTTAGATCCTGACG
GCAAATGCTGGCCGGAATCTAGGACTGC
CGTTTACGA CCGGCCTTAGATCCTGACG U C G
A A A
G C
RNA Polymerase
Makes a complementary copy of RNA from DNA
Transcription

4. Cell Division and Gene Expression
The Need for Cell Reproduction
- The Nature of Chromosomes
- The Cell Cycle
- Mitosis and Cytokinesis
- Cancer Cells: Abnormal Cell Cycle
The Expression of Genes as Proteins: DNA gene --> RNA --> Protein
- Transcription by RNA Polymerase
- The Three Types of RNA
- Translation by Ribosome 4

5. 3 Types of RNA – Each With a Different Job
Messenger RNA (mRNA)
Carries copy of gene information
to the ribosome to make protein
anticodon
Transfer RNA (tRNA) =
CUG
C U G
Carries amino acids to the ribosome for linking; identified by anticodon “sign”
Part of the structure of
the ribosome; key
component in amino
acid linking machinery
Ribosomal RNA (rRNA)

6. Anatomy of a Messenger RNA
Trailer
Leader
Figure 10.17

7. Cell Division and Gene Expression
The Need for Cell Reproduction
- The Nature of Chromosomes
- The Cell Cycle
- Mitosis and Cytokinesis
- Cancer Cells: Abnormal Cell Cycle
The Expression of Genes as Proteins: DNA gene --> RNA --> Protein
- Transcription by RNA Polymerase
- The Three Types of RNA
- Translation by Ribosome
- The Genetic Code 7

8. How Gene Instructions are Communicated

9. mRNA Codon Dictionary of the Genetic Code
SECOND BASE U C A G
UUU
UCU
UAU
UGU U
Phe
Tyr
Cys
UUC
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
AUU
ACU
AAU
AGU U
Asn
Ser
AUC
Ile
ACC
AAC
AGC C A
Thr
AUA
ACA
AAA
AGA A
Met or
Lys
Arg
AUG
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

10. CGTTTACGACCGGCCTTAGATCCTGACG
Central Dogma: DNARNAProtein
DNA template strand:
CGTTTACGACCGGCCTTAGATCCTGACG
Transcription by RNA polymerase
mRNA: GCAAAUGCUGGCCGGAAUCUAGGACUGC
Translation by ribosome
Protein: Met -
Leu -
Ala -
Gly -
Ile
Translation

11. Cell Division and Gene Expression
The Need for Cell Reproduction
- The Nature of Chromosomes
- The Cell Cycle
- Mitosis and Cytokinesis
- Cancer Cells: Abnormal Cell Cycle
The Expression of Genes as Proteins: DNA gene --> RNA --> Protein
- Transcription by RNA Polymerase
- The Three Types of RNA
- Translation by Ribosome
-The Genetic Code
-The Three Steps of Translation: Initiation, Elongation, & Termination 11

12. Simplified Diagram of a Ribosome
Transcription has 3 parts:
Initiation, where the ribosome assembles with mRNA
Elongation, where the protein chain grows
Termination, where the new protein is released

13. Growing amino acid chain (polypeptide)
Translation
Initiation
Growing amino acid chain (polypeptide)
tRNA
E P A
mRNA
Termination
Elongation

14. The Big Picture Regarding DNA->RNA -> Protein
Figure 10.10

15. Cell Division and Gene Expression
The Need for Cell Reproduction
- The Nature of Chromosomes
- The Cell Cycle
- Mitosis and Cytokinesis
- Cancer Cells: Abnormal Cell Cycle
The Expression of Genes as Proteins: DNA gene --> RNA --> Protein
- Transcription by RNA Polymerase
- The Three Types of RNA
- Translation by Ribosome 15