1. DNA, RNA, and Protein Synthesis
DNA, RNA, and Protein Synthesis

2. Structure of DNA
DNA – base pairs carry the genetic code for the sequence of the amino acids
Section 12-1
Nucleotide
Hydrogen bonds
Sugar-phosphate backbone
Key
Adenine (A)
Thymine (T)
Cytosine (C)
Guanine (G)

3. Nucleotides in the DNA strand carry the code for proteins
Image by: Riedell

4. Nitrogen bases =“Steps of ladder”
Purines (2 rings)
Phosphate group G C
Pyrimidines
(1 ring)
Deoxyribose sugar T
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5. Nitrogen bases =“Steps of ladder”
ADENINE
Phosphate group G
GUANINE C
CYTOSINE
Deoxyribose sugar
THYMINE T
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6. CHARGAFF’S RULES A = T G = C _________ _________
_________ _________
At time no one knew why…
now we know its because
Adenine always bonds across with____________
Guanine always bonds across with ____________
THYMINE
CYTOSINE
Image from:

7. RNA and PROTEIN SYNTHESIS
DNA is safely stored in the nucleus. mRNA (messenger RNA) brings a copy of the code out to the cytoplasm.
RNA and PROTEIN SYNTHESIS
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8. Transcription - Making a copy of the DNA code
Adenine (DNA and RNA)
Cystosine (DNA and RNA)
Guanine(DNA and RNA)
Thymine (DNA only)
Uracil (RNA only)
RNA polymerase
DNA
RNA
Enzyme called RNA polymerase separates strands of DNA,
then uses one strand as a template to assemble an mRNA copy.
mRNA will carry the “script” out of the nucleus to the cytoplasm

9. RNA- the Other Nucleic Acid
Also made of nucleotides
Sugar is ribose instead
of deoxyribose.
RNA is single stranded, instead of doubled stranded.
Contains uracil instead
of thymine.

10. Replication Done only by DNA Nucleus of the eukaryotic cells Noun
The action of copying or reproducing something.
A copy.
Synonyms
reply - rejoinder - answer - response - replica - copy
Done only by DNA
Nucleus of the eukaryotic cells

11. Transcription Noun A written or printed representation of something.
The action or process of transcribing something.
Synonyms
transcript – re-write
Done by the mRNA
Nucleus of an eukaryotic cell
Contains the codon

12. Translation
Noun
The process of translating words or text from one language into another.
A written or spoken rendering of the meaning of a word or system.
Synonyms
rendering - rendition – interpretation
Done by tRNA
Contains the anticodon
Contains the amino acid

13. MASTER PLAN DNA stays safe in nucleus
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TRANSCRIPTION (DNA→ RNA)
& PROCESSING (remove interons) takes place in nucleus
TRANSLATION (RNA→ proteins)
takes place on ribosomes in cytoplasm
“Blueprints” of master plan
are carried to building site

14. Translation - Translating the base pair codes into an amino acid sequence
mRNA – the copy of the code
sequence of base pairs
tRNA – carries the amino acid to the ribosome as coded for in the mRNA – codons code for specific amino acids.

15. EACH tRNA carries only one kind of _____________ amino acid ANTICODON
on tRNA
matches up with
________
on mRNA
CODON
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16. HOW CAN JUST 4 BASES GIVE DIRECTIONS TO MAKE 20 AMINO ACIDS?
Message is read in groups of 3 = _________
UCGCACGGU
UCG-CAC-GGU
CODON
Serine
- Histidine
- Glycine
Codons represent different amino acids

18. AUG The mRNA Code 64 possible codons
Some amino acids have more than one
codon.
START= _______
3 codons for _____
AUG
STOP

20. Translation Translating the base pair codes into an amino acid sequence

21. Translation (continued)

22. Summary of protein synthesis
DNA strand in nucleus
Occurs in the nucleus
RNA message copied from DNA
mRNA moves out to cytoplasm
Occurs in the cytoplasm at the ribosome

23. A graphic to show you translation to sequence the protein
ribosome
codon
carries a specific amino acid depending upon its code

25. What is Gel Electrophoresis?
Gel electrophoresis is a widely used technique for separating electrically charged molecules.
It is a central technique in molecular biology and genetics laboratories, because it lets researchers separate and purify the nucleic acids DNA and RNA and proteins, so they can be studied individually.
Gel electrophoresis is often followed by staining or blotting procedures used to identify the separated molecules.
Read more:

26.  Gel Electrophoresis

27.  Gel Electrophoresis

29. Test February 14/15 Please Study!