1. From Gene to Protein

2. Bodies  Cells  DNA Bodies are made up of cells
All cells run on a set of instructions spelled out in DNA

3. Watson & Crick: Structure of DNA
1953 | 1962
Watson & Crick: Structure of DNA
Rosalind Franklin
Francis Crick
James Watson

4. Structure of DNA: Paired bases
Bases match together
A pairs with T
A : T
C pairs with G
C : G
weak bonds between bases join 2 strands
can separate easily

5. DNA  Cells  Bodies How does DNA code for cells & bodies?
how are cells and bodies made from the instructions in DNA

6. DNA  Proteins  Cells  Bodies
DNA has the information to build proteins
proteins
cells
DNA gets all the glory, Proteins do all the work
bodies

7. What do we know? DNA Proteins
DNA is the genetic information
Proteins
proteins run living organisms
enzymes
all chemical reactions in living organisms are controlled by enzymes (proteins)
structure
all living organisms are built out of proteins
DNA is the instructions for making proteins

8. What do we know? DNA Proteins
DNA is in the nucleus
want to keep it there = protected
“locked in the vault”
Proteins
made by a “protein factory” in cytoplasm
ribosomes
Need to get gene (DNA) information from nucleus to cytoplasm
need a messenger!
need a copy of DNA
mRNA
nucleus

9. DNA RNA mRNA Who is the messenger? build proteins messenger RNA (mRNA)
nucleus
cytoplasm

10. From nucleus to cytoplasm
transcription
DNA
mRNA
protein
translation
trait
nucleus
cytoplasm

11. DNA vs. RNA DNA RNA deoxyribose sugar nitrogen bases double stranded
G, C, A, T
T = thymine
T : A
C : G
double stranded
RNA
ribose sugar
nitrogen bases
G, C, A, U
U = uracil
U : A
C : G
single stranded

12. DNA vs. RNA
DNA
RNA
DNA

13. Transcription Making mRNA from DNA
DNA strand is the template (pattern)
match bases
U : A
G : C
Enzyme
RNA polymerase

14. Matching bases of DNA & RNA
Double stranded DNA unzips T G G T A C A G C T A G T C A T C G T A C C G T

15. Matching bases of DNA & RNA
Double stranded DNA unzips T G G T A C A G C T A G T C A T C G T A C C G T

16. Matching bases of DNA & RNA
Match RNA bases to DNA bases on one of the DNA strands C U G A G U G U C U G C A A C U A A G C
RNA
polymerase U A G A C C T G G T A C A G C T A G T C A T C G T A C C G T

17. Matching bases of DNA & RNA
U instead of T is matched to A
TACGCACATTTACGTACGCGG
DNA
AUGCGUGUAAAUGCAUGCGCC
mRNA

18. What do we know? DNA mRNA Proteins What reads RNA? need a mRNA reader!
nucleus
What do we know?
DNA
instructions remain in nucleus
mRNA
has the instructions for building proteins from DNA
Proteins
built as chains of amino acids
What reads RNA?
need a mRNA reader!
ribosome U C A G aa

19. DNA mRNA protein trait From gene to protein cytoplasm transcriptionaa
transcription
translation
DNA
mRNA
protein
ribosome
mRNA leaves nucleus through nuclear pores U C A G
proteins synthesized by ribosomes using instructions on mRNA
trait
nucleus

20. What do we know? mRNA Proteins What reads mRNA?U C A G aa
mRNA
has the instructions for building proteins from DNA
Proteins
built as chains of amino acids
What reads mRNA?
ribosome
What brings the right amino acid to attach to the protein chain?
need an amino acid transporter!
ribosome

21. DNA mRNA protein trait From gene to protein tRNA
Who is the transporter?
tRNA transports amino acids aa
transcription
translation
DNA
mRNA
protein
ribosome
tRNA aa U C A G
trait
nucleus
cytoplasm

22. RNA to protein aa aa aa aa aa aa aa aa mRNA leaves nucleus
mRNA goes to ribosomes in cytoplasm
Proteins built from instructions on mRNA
How?
mRNA A C C A U G U C G A U C A G U A G C A U G G C A aa aa aa aa aa aa aa aa

23. How does mRNA code for proteins?
TACGCACATTTACGTACGCGG
DNA
AUGCGUGUAAAUGCAUGCGCC
mRNA ?
Met Arg Val Asn Ala Cys Ala
protein
How can you code for 20 amino acids with only 4 nucleotide bases (A,U,G,C)?

24. mRNA codes for proteins in triplets
TACGCACATTTACGTACGCGG
DNA
codons
ribosome
ribosome
AUGCGUGUAAAUGCAUGCGCC
mRNA
AUGCGUGUAAAUGCAUGCGCC
mRNA ?
Met Arg Val Asn Ala Cys Ala
protein
Codon
block of 3 nucleotides

25. The mRNA code For ALL life! Code is redundant Start codon Stop codons
strongest support for a common origin for all life
Code is redundant
several codons for each amino acid
mutation insurance!
Strong evidence for a single origin in evolutionary theory.
Start codon
AUG
methionine
Stop codons
UGA, UAA, UAG

26. How are the codons matched to amino acids?
TACGCACATTTACGTACGCGG
DNA
AUGCGUGUAAAUGCAUGCGCC
mRNA
codon
UAC
Met
GCA
Arg
tRNA
CAU
Val
anti-codon
amino acid

27. mRNA to protein = Translation
The reader ribosome
The transporter  transfer RNA (tRNA)
ribosome
mRNA A C C A U G U C G A U C A G U A G C A U G G C A U G G aa
tRNA U A C aa
tRNA G A aa
tRNA C
tRNA aa A G U aa aa

28. DNA mRNA protein trait From gene to protein tRNA transcriptionaa
transcription
translation
DNA
mRNA
protein
ribosome
tRNA aa U C A G
trait
nucleus
cytoplasm

29. cytoplasm
transcription
translation
protein
nucleus
trait

30. From gene to protein

31. DNA transcription mRNA ribosome translation
amino acids
mRNA
Can you tell the story?
protein
ribosome
tRNA
translation

32. Any Questions??

33. DNA mRNA protein From gene to protein tRNA Who is the transporter?
tRNA transports amino acids aa
transcription
translation
DNA
mRNA
protein
ribosome
tRNA aa U C A G
nucleus
cytoplasm

34. DNA mRNA protein From gene to protein tRNA transcription translationaa
transcription
translation
DNA
mRNA
protein
ribosome
tRNA aa U C A G
nucleus
cytoplasm