1. How Are Genes & Proteins Related?
GENETIC INFO: DNA’s Nucleotide Sequence
EXPRESSED AS: Protein’s Amino Acid Sequence
AN EXAMPLE: 2 DNA Base Sequences
GTG CAC CTG ACT CCT GAG GAG normal Hb
GTG CAC CTG ACT CCT GTG GAG sickle Hb
Cell Movies 102/SikldCellsInCapQTmovie
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2. THE CENTRAL DOGMA: DNA RNA PROTEIN
transcription
rRNA
+ proteins
mRNA
tRNA
ribosomes
tRNA
amino acids
translation
Figure :10-8
Title:
An overview of information flow in a cell, from gene transcription to chemical reactions catalyzed by enzymes
Caption:
modification
degradation
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3. gene DNA (nucleus) (cytoplasm) Transcription messenger RNA Translation
Figure :10-3
Title:
Genetic information flows from DNA to RNA to protein
Caption:
(a) During transcription, the nucleotide sequence in a gene specifies the nucleotide sequence in a complementary RNA molecule. For protein-encoding genes, the product is an mRNA molecule that exits from the nucleus and enters the cytoplasm. (b) During translation, the sequence in an mRNA molecule specifies the amino acid sequence in a protein.
Translation
protein

4. THE CENTRAL DOGMA: DNA RNA PROTEIN
transcription
rRNA
+ proteins
mRNA
tRNA
ribosomes
tRNA
amino acids
translation
Figure :10-8
Title:
An overview of information flow in a cell, from gene transcription to chemical reactions catalyzed by enzymes
Caption:
modification
degradation
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5. How Are Genes & Proteins Related?
Genetic Information Is
Transcribed into RNA
Then Translated into Protein
Genetic info: from DNA to RNA to protein
(F10.3 p. 166)
Processes Involved in the Use and Inheritance of Genetic Information
(T10.2 p. 167)
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6. Figure :10-T2
Title:
Processes Involved in the Use and Inheritance of Genetic Information
Caption:

7. How Are Genes & Proteins Related?
DNA’s Nucleotide Sequence Expressed as Protein’s Amino Acid Sequence
Most Genes Contain the Information for the Synthesis of a Single Protein
DNA Provides Instructions for Protein Synthesis via RNA Intermediaries
DNA & RNA Comparison (T10.1 p. 165)
Cells make 3 major types of RNA (F10.2 p. 166)
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8. Figure :10-T1
Title:
A Comparison of DNA and RNA
Caption:

9. Transcription Transcription: (F10.4 p. 168) Initiation: Elongation:
RNA synthesis from DNA instructions
3 Steps
Initiation:
RNA Polymerase Binds to the Promoter of a Gene
Elongation:
Proceeds Until RNA Polymerase Reaches a Termination Signal
Termination:
RNA Polymerase “Falls Off” the DNA
Transcription in Action (F10.5 p. 169)
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10. DNA gene 1 gene 2 gene 3 RNA polymerase DNA RNA DNA template strand
Initiation
RNA
polymerase
DNA
RNA polymerase binds to the promoter region of DNA near the beginning of a gene, separating the double helix near
the promoter.
Elongation
RNA
DNA template strand
RNA polymerase travels along the DNA template strand, catalyzing the addition of ribose nucleotides into an RNA
molecule. The nucleotides in the RNA are complementary to the template strand of the DNA.
Termination
Figure :10-4
Title:
Transcription is the synthesis of RNA from instructions in DNA
Caption:
A gene is a segment of a chromosome's DNA. One of the DNA strands will serve as the template for the synthesis of an RNA molecule with bases complementary to the bases in the DNA strand. Question If the other DNA strand of this molecule were the template strand, in which direction would the RNA polymerase travel?
At the end of a gene, RNA polymerase encounters a sequence of DNA called a termination signal. RNA polymerase
detaches from the DNA and releases the RNA molecule.
Conclusion of transcription
RNA
After termination, the DNA completely rewinds into a double helix. The RNA molecule is free to move from the
nucleus to the cytoplasm for translation, and RNA polymerase may move to another gene and begin transcription
once again.

11. gene RNA molecules DNA Figure :10-5 Title: RNA transcription in action
Caption:
This electron micrograph shows the progress of RNA transcription in the egg of an African clawed toad. In each treelike structure, the central "trunk" is DNA and the "branches" are RNA molecules. A series of RNA polymerase molecules are traveling down the DNA, synthesizing RNA as they go. The beginning of the gene is on the left. The short RNA molecules on the left have just begun to be synthesized; the long RNA molecules on the right are almost finished.
DNA

12. Translation The Process of Protein Synthesis mRNA: Ribosomes : tRNA:
mRNA Base Sequence into Protein Amino Acid Sequence (F10.6 p. 171)
mRNA:
Carries Information for Protein Synthesis from the Nucleus to the Cytoplasm
Ribosomes :
“Dumb” Workbench Where Amino Acids Are Hooked Together
2 Subunits, Each Composed of rRNA & Protein
tRNA:
Decodes mRNA Base Sequence into Protein Amino Acid Sequence
Complementary Base Pairing of tRNA Anticodon to mRNA Codon
The Genetic Code (Codons of mRNA) (T10.3 p. 167)
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13. Messenger RNA (mRNA) Ribosome: contains ribosomal RNA (rRNA)
catalytic site
large
subunit 1 2
tRNA/amino acid
binding sites
small
subunit
Figure :10-2
Title:
Cells synthesize three major types of RNA
Caption:
Transfer RNA (tRNA)
attached
amino acid
anticodon

14. mRNA ribosomes F5.7 P85 0.05 micrometers
Figure :5-7
Title:
Ribosomes
Caption:
Ribosomes may be found free in the cytoplasm either singly or strung along messenger RNA molecules as they participate in protein synthesis. Ribosomes also stud the rough endoplasmic reticulum, giving it a rough appearance and allowing the synthesis of proteins within the ER.
ribosomes
F5.7 P85
0.05 micrometers
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15. DNA mRNA tRNA protein gene etc. complementary DNA strand template DNA
codons
mRNA
etc.
Figure :10-7
Title:
Complementary base pairing is critical to decode genetic information
Caption:
(a) DNA contains two strands: the template strand is used by RNA polymerase to synthesize an RNA molecule. (b) Bases in the template strand of DNA are transcribed into a complementary mRNA. Codons are sequences of three bases that specify an amino acid or a stop during protein synthesis. (c) Unless it is a stop codon, each mRNA codon forms base pairs with the anticodon of a tRNA molecule that carries a specific amino acid. (d) The amino acids borne by the tRNAs are joined together to form a protein.
anticodons
tRNA
etc.
amino acids
protein
etc.

16. Figure :10-T3
Title:
The Genetic Code (Codons of mRNA)
Caption:

17. Translation Translation: ACTIVITY Initiation: Elongation :
Protein Synthesis from mRNA Information
3 steps
Initiation:
mRNA & tRNA Bind to a Ribosome
Elongation :
tRNA Anticodons Form Complementary Base Pairs to mRNA Anticodons
tRNA Brings In Next Amino Acid
rRNA Transfers This Amino Acid from tRNA to Growing Amino Acid Polymer
Protein Synthesis Proceeds One Amino Acid at a Time Until ……………..
Termination:
A Stop Codon Is Reached
mRNA & Ribosome Fall Apart
Completed Protein is Released
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18. Translation is the process of protein synthesis
Initiation:
amino acid
second tRNA binding site
catalytic site
tRNA
methionine
tRNA
first tRNA
binding
site
large
ribosomal
subunit
initiation
complex
mRNA
small
ribosomal
subunit
A tRNA with an attached methionine amino acid binds to a small ribosomal subunit, forming
an initiation complex
The initiation complex binds to an mRNA molecule. The methionine (met) tRNA anticodon (UAC) base-pairs with the start codon (AUG) of the mRNA.
The large ribosomal subunit binds
to the small subunit. The methionine
tRNA binds to the first tRNA site on
the large subunit.
Elongation:
catalytic site
catalytic site
initiator
tRNA detaches
peptide
bond
ribosome moves one codon to right
The second codon of mRNA (GUU) base-pairs with the anticodon (CAA) of a second tRNA carrying the amino acid valine (val). This tRNA binds to the second tRNA site on the large subunit.
The catalytic site on the large subunit
catalyzes the formation of a peptide
bond linking the amino acids methionine
and valine. The two amino acids are now
attached to the tRNA in the second
binding position.
The "empty" tRNA is released and
the ribosome moves down the mRNA,
one codon to the right. The tRNA that
is attached to the two amino acids is
now in the first tRNA binding site and
the second tRNA binding site is empty.
Figure :10-6
Title:
Translation is the process of protein synthesis
Caption:
Protein synthesis, or translation, decodes the base sequence of an mRNA into the amino acid sequence of a protein. Question Examine panel (i) above. If mutations changed all of the guanine molecules visible in the mRNA sequence shown here to uracil, how would translated peptide differ from the one shown?
Termination:
catalytic site
completed
peptide
stop codon
The third codon of mRNA (CAU) base-pairs with the anticodon (GUA) of a tRNA carrying the amino acid histidine (his). This tRNA enters the second tRNA binding site on the large subunit.
The catalytic site forms a new peptide bond between valine and histidine. A three-amino-acid chain is now attached to the tRNA in the second binding site. The tRNA in the first site leaves, and the ribosome moves one codon over on the mRNA.
This process repeats until a stop codon is reached; the mRNA and the completed peptide are released from the ribosome, and the subunits separate.

19. THE CENTRAL DOGMA IN ACTION
Recap:
Convert DNA Base Sequence mRNA Base Sequence into Protein Amino Acid Sequence
2 Processes: Transcription & Translation
Complementary Base Pairing:
Critical to Decode Genetic Information (F10.7 p. 172)
Occurs Twice
Transcription: DNA Base Sequence Converted to mRNA Base Sequence
Translation: mRNA Codons Match to tRNA Anticodons
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20. Mutations: What They Are & How They Affect Gene Function
Mutation = A Change in DNA Base Sequence
Nucleotide Substitutions, Insertions, or Deletions
External Agents – Chemicals, Radiation
Uncorrected Replication Errors
“Jumping Genes” Burkitt’s Lymphoma
May Affect Protein Structure & Function
Sickle Cell Anemia = 1 BP Mutation in Hemoglobin Gene (T10.4 p. 173)
GTG CAC CTG ACT CCT GAG GAG normal Hb
GTG CAC CTG ACT CCT GTG GAG sickle Hb
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21. Figure :10-T4
Title:
Effects of Mutations in the Hemoglobin Gene
Caption:

22. Mutations: What They Are & How They Affect Gene Function
Mutations: Provide Variability for Evolution
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23. Figure 21.13  Homeotic mutations and abnormal pattern formation in Drosophila
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24. Figure 21.x5 Normal and double winged Drosophila
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25. Regulation of Gene Expression
Critical for an Organism’s Development & Health
Eukaryotic Cells May Regulate the Transcription of Individual Genes, Regions of Chromosomes, or Entire Chromosomes
Regulatory Proteins: Bind to Gene’s Promoter Alter the Transcription of Individual Genes
Some Regions of Chromosomes Are Condensed & Not Transcribed
Entire Chromosomes May Be Inactivated, Preventing Transcription
Barr bodies (F10.9 p. 177)
X chromosome inactivation (F10.10 p. 179)
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26. transcription rRNA + proteins mRNA tRNA ribosomes tRNA amino acids
translation
Figure :10-8
Title:
An overview of information flow in a cell, from gene transcription to chemical reactions catalyzed by enzymes
Caption:
modification
degradation

27. exons DNA introns promoter DNA transcription initial RNA transcript
Eukaryotic gene structure
exons
DNA
promoter
introns
A typical eukaryotic gene consists of sequences of DNA called exons, which code for the amino
acids of a protein (medium blue), and intervening sequences called introns (dark blue), which do
not. The promoter determines where RNA polymerase will begin transcription.
RNA synthesis and processing in eukaryotes
DNA
transcription
initial
RNA transcript
Figure: E10-1
Title:
Eukaryotic genes contain introns and exons
RNA splicing
introns
cut out
and
broken
down
completed mRNA
to cytoplasm
for translation
RNA polymerase transcribes both the exons and introns, producing a long RNA molecule. Enzymes
in the nucleus then cut out the RNA introns and splice together the exons to form the true mRNA,
which moves out of the nucleus and is translated on the ribosomes.

28. Eukaryotic gene structure
exons
DNA
promoter
introns
Figure: E10-1 part a
Title:
Eukaryotic genes contain introns and exons part a Eukaryotic gene structure
A typical eukaryotic gene consists of sequences of DNA called exons, which code for the amino
acids of a protein (medium blue), and intervening sequences called introns (dark blue), which do
not. The promoter determines where RNA polymerase will begin transcription.

29. RNA synthesis and processing in eukaryotes
DNA
transcription
initial
RNA transcript
RNA splicing
introns
cut out
and
broken
down
completed mRNA
Figure: E10-1 part b
Title:
Eukaryotic genes contain introns and exons part b RNA synthesis and processing in eukaryotes
to cytoplasm
for translation
RNA polymerase transcribes both the exons and introns, producing a long RNA molecule.
Enzymes in the nucleus then cut out the RNA introns and splice together the exons to form
the true mRNA, which moves out of the nucleus and is translated on the ribosomes.

30. 10.5 How Are Genes Regulated?
Eukaryotic Cells May Regulate the Transcription of Individual Genes, Regions of Chromosomes, or Entire Chromosomes
Regulatory Proteins That Bind to the Gene’s Promoter Alter the Transcription of Individual Genes
Some Regions of Chromosomes Are Condensed and Not Normally Transcribed
Entire Chromosomes May Be Inactivated, Thereby Preventing Transcription
Figure Barr bodies (p. 177)
Figure E10.2 Androgen insensitivity leads to female features
Figure E10.3 A 48-year-old woman with Werner syndrome
Figure Inactivation of the X chromosome regulates gene expression (p. 179)
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31. Figure :10-10
Title:
Inactivation of the X chromosome regulates gene expression
Caption:
This female calico cat carries a gene for orange fur on one X chromosome and a gene for black fur on her other X chromosome. Inactivation of different X chromosomes produces the black and orange patches. The white color is due to an entirely different gene that prevents pigment formation altogether. Question Most orange cats are male. Why?