1. BELL RINGER What are the base pairing rules for DNA replication?
Where does DNA Replication occur?
What is the function of DNA?
Do all of your cells have the exact same DNA?

2. The building of proteins
Protein Synthesis
The building of proteins
This PowerPoint has many animated slide progressions. You may only want to print the following slides: 1-11; 33-47; 62; 64-65

3. Protein Synthesis Protein Synthesis is the building of Proteins
The monomer of a protein is an amino acid
DNA holds the instructions to synthesize proteins
Functions of proteins include
Structure (hair, skin, claws, muscle)
Cell communication (hormones)
Digestion and synthesis (enzymes)

4. SO…how does a cell make proteins anyway?

5. There are two important nucleic acids involved in this process...
DNA Deoxyribonucleic acid
RNA Ribonucleic acid
What is the monomer
of a nucleic acid?
Nucleotide!!
DNA and RNA are both nucleic acids.

7. Let’s Compare DNA & RNA RNA: ribonucleic acid
RNA is SINGLE stranded
Sugar = ribose
RNA contains bases Adenine, URACIL Cytosine and Guanine
RNA is found in both the NUCLEUS AND CYTOPLASM
DNA: deoxyribonucleic acid
DNA is DOUBLE stranded
Sugar = deoxyribose
DNA contains bases Adenine, Thymine, Guanine, Cytosine.
DNA found ONLY in the NUCLEUS
This is a review of DNA and RNA.
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8. Let’s Compare DNA & RNA RNA: ribonucleic acid
RNA is SINGLE stranded
Sugar = ribose
RNA contains bases Adenine, URACIL Cytosine and Guanine
RNA is found in both the NUCLEUS AND CYTOPLASM
DNA: deoxyribonucleic acid
DNA is DOUBLE stranded
Sugar = deoxyribose
DNA contains bases Adenine, Thymine, Guanine, Cytosine.
DNA found ONLY in the NUCLEUS
Both contain Nucleotides made of a sugar, phosphate and nitrogen base.
Both have bases A, C, and G
This is a review of DNA and RNA.
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9. Nucleic Acid COMPLEMENTARY Base Rules
DNA
RNA
A – T
C – G
5’ – 3’
A – U
C – G

10. There are three types of RNA
mRNA
mRNA: messenger RNA
Transcription
3 mRNA bases = codon = amino acid
tRNA: transfer RNA
Translation
3 tRNA bases = anTi-codon
Found in the cytoplasm
tRNA
towing
Amino acid
Remind students that there are three different RNA molecules that are involved with protein synthesis and briefly go over their function.
mRNA: messenger RNA. It carries the DNA message from the nucleus to the ribosomes. tRNA: transfer RNA. It carries amino acids from the cytoplasm to the ribosomes.
rRNA: ribosomal RNA. It is found at the ribosomes.
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rRNA: ribosomal RNA

11. Protein Synthesis(to make)
transcription
translation
Trait
During gene expression, the information in DNA is first transcribed in the nucleus as a molecule of mRNA and then translated in the cytoplasm and used to build a protein.
DNA
RNA
Protein

12. Transcription and Translation
The process of going from DNA to mRNA is Transcription The process of going from mRNA to protein is Translation

13. Protein Synthesis

14. Transcription (DNA mRNA)
Occurs in the nucleus of a eukaryotic cell
Steps to transcription
DNA unzips itself
mRNA is made by forming the complementary strand along the unzipped portion of DNA
DNA’s code is copied into groups of three bases called a codon
3 mRNA bases = 1 codon = 1 amino acid
mRNA will then leave the nucleus and find a ribosome in the cytoplasm for the next step in protein synthesis
Practice: transcribe the DNA to mRNA
AAA CGA TCC GAT CAT GGG

15. Practice Transcribing (DNA to mRNA)
Think…which rules apply (DNA or RNA)…any time RNA is involved RNA rules apply (A-U and C-G).
DNA strand: AAA CGA TCC GAT CAT GGG
Transcription
mRNA strand: UUU GCU AGG CUA GUA CCC
How many codons are in the mRNA strand above? 6
How many amino acids will be coded for in the mRNA strand above? 6

16. Amino Acids (monomer of proteins)
There are 20 known amino acids present in living things
Each mRNA codon “codes” for a specific amino acid
3 mRNA bases = 1 codon
1 codon = 1 amino acid
We use a “codon chart” to determine what amino acid is being coded for
A chain of amino acids is a protein

17. mRNA Codon chart U C A G First Base Second Base Third mRNA codon: AUCU C A G
Phenylalanine
Leucine
Serine
Tyrosine
Stop
Cysteine
Tryptophan
Proline
Histidine
Glutamine
Arginine
U C A G
Isoleucine
Methionine
Threonine
Asparagine
Lysine
Valine
Alanine
Aspartic Acid
Glutamic Acid
Glycine
First
Base
Second Base
Third
2nd
Explain how to use the chart to find the amino acids that are made.
Chart taken from the University of Arizona’s Biology Project

20. Translation (mRNA protein)
Translation is the process of going from mRNA to a protein
tRNA reads the mRNA codons and brings back the appropriate amino acid to the ribosome
tRNA is clover leaf shaped
On one end it carries the amino acid like a tow truck
At the other end it has a three letter triplet called an anti codon

21. tRNA structure: 2 parts
Amino acid
anTi-codon

22. Find the tRNA anticodon
AUG CCA
GCU GUA
What type of RNA?

23. Translation- tRNA turns code into proteins
anTi-codons are the complement to the mRNA codon
3 tRNA bases = anTi-codon = complement to codon

24. Protein synthesis
Begins when a tRNA brings a START amino acid to a ribosome
Continues until a STOP is delivered to a ribosome
How does the ribosome know when to stop synthesizing a protein?

25. It is possible for some amino acids to have more than one codon.
There are three stop codons…they are UAA, UGA and UAG.
When a STOP codon is reached, the building of that protein is finished
There is also one START codon…AUG.
When a ribosome is delivered a START codon, it starts to build a protein
This will continue until a STOP codon is delivered

26. Proteins The monomer (building block) of a protein is an amino acid
Each mRNA codon = 1 amino acid
Ribosomes bond the amino acids that are delivered by tRNA together to form different proteins
The bonds between amino acids are called “peptide” bonds (peptide = protein)

27. Here’s the process…animated!
UACUGCUAA
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28. Here’s the process…animated!
UACUGCUAA
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29. Here’s the process…animated!
UACUGCUAA
tyrosine
AUG
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30. Here’s the process…animated!
UACUGCUAA
tyrosine
AUG
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31. Here’s the process…animated!
UACUGCUAA
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tyrosine

32. Here’s the process…animated!
UACUGCUAA
threonine
ACG
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tyrosine

33. Here’s the process…animated!
UACUGCUAA
threonine
ACG
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tyrosine

34. Here’s the process…animated!
UACUGCUAA
The slide is animated; translation occurs automatically
tyrosine
threonine

35. Here’s the process…animated!
UACUGCUAA
The slide is animated; translation occurs automatically
tyrosine
threonine

36. Here’s the process…animated!
UACUGCUAA
isoleucine
AUU
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tyrosine
threonine

37. Here’s the process…animated!
UACUGCUAA
isoleucine
AUU
The slide is animated; translation occurs automatically
tyrosine
threonine

38. Here’s the process…animated!
UACUGCUAA
The slide is animated; translation occurs automatically
tyrosine
threonine
isoleucine

39. Here’s the process…animated!
UACUGCUAA
The slide is animated; translation occurs automatically
tyrosine
threonine
isoleucine

40. Here’s the process…animated!
UACUGCUAA
The slide is animated; translation occurs automatically
tyrosine
threonine
isoleucine

41. Here’s the process…animated!
UACUGCUAA
The slide is animated; translation occurs automatically
tyrosine
threonine
isoleucine

42. Here’s the process…animated!
UACUGCUAA
The slide is animated; translation occurs automatically
tyrosine
threonine
isoleucine

43. Can you tell the story? DNA mRNA amino acids tRNA mRNA
Polypeptide (protein) 5'
tRNA
ribosome

44. Label the diagram
Protein
tRNA
mRNA
Amino acid
Ribosome

46. The “Central Dogma” or BIG IDEA
transcription
translation
DNA
protein
trait
mRNA
To get from the chemical language of DNA to the chemical language of proteins requires 2 major stages:
transcription and translation
replication

47. DNA  Proteins  Cells  Bodies

48. What is gene expression?
ALL of the different characteristics of ALL organisms is a result of PROTEIN SYNTHESIS. You are seeing the physical expression of the SEQUENCE of NITROGEN BASES determined the proteins that will be expressed.
(ATT CGC TGG)
NOT

49. Differential Gene Expression
All of the somatic (body) cells in an organism are genetically identical
Differences between cell types (skin, muscle, kidney, blood, etc.) result from differential gene expression, the expression of different genes by cells with the same genome
Gene expression is a regulated process
Hormones signal the turning on and off of genes

50. Regulated Gene Expression
Temperature will the turning on and off of protein synthesis which leads to gene expression in mammalian fur color

51. Mutations
Mutations (errors) in DNA can result abnormalities in gene expression and can lead to diseases including cancer

52. In summary… DNA contains the instruction to syntesize proteins
DNA never leaves the nucleus
RNA acts as a set of working instructions for ribosomes to make proteins
This process is also known as gene expression.