DNA => RNA => Protein

1. DNA => RNA => Protein Central Dogma of Life

2. DNA • Name: Deoxyribonucleic Acid • “Molecule of Life” • Stays in the nucleus of eukaryotes • Codes for RNA and ultimately proteins • Structure: Double stranded (double helix) • Monomers: Nucleotides • Adenine, Guanine, Cytosine, & Thymine

3. RNA • Name: Ribonucleic Acid • Disposable copy of DNA- moves to the cytoplasm to make proteins • Structure: Single Stranded • Monomer: Nucleotides • Adenine, Guanine, Cytosine, & Uracil • Three kinds • mRNA - messenger • tRNA - transfer • rRNA - ribosomes

4. Nucleotide • Remember that a nucleotide is made up of three parts: • Phosphate group • 5 carbon sugar • Nitrogenous base • The nitrogenous base differs • A, T, C or G in DNA • A, U, C or G in RNA

5. DNA Replication • DNA must be replicated • When does this happen during the cell cycle? • When does DNA get replicated? • When new cells need to be made • To replace dead or damaged cells • To grow and develop • To form a new life- fertilization birth • 2 strands of DNA run in opposite directions

6. DNA Replication • Enzymes involved • DNA helicase- unwinds, unzips double stranded DNA, exposes nitrogenous bases so they can be based paired • DNA polymerase- adds new DNA nucleotides • DNA replication is semi-conservative, meaning that each new DNA strand is made of one old and one new strand

8. Protein • Monomers: Amino Acids • Functions: • Enzymes • Structural Proteins • In the cell membrane • Give characteristics to cells • They make you, YOU!

9. Genes • Segments of DNA • The code on the DNA codes for a PROTEIN.

10. How to get from DNA to Proteins • Transcription - The rewritten language of DNA nucleotides to RNA nucleotides • Translation - The translation from the language of nucleotides to the language of amino acids.

11. Transcription: From DNA => mRNA • Rewriting the nucleotide code • In the Nucleus • The DNA transcribed is for a certain protein (from a gene) • DNA splits • 1 Strand is used as a template • RNA polymerase is used to build mRNA strand. • Once complete the mRNA goes into the cytoplasm.

12. Codons • Series of 3 nucleotides on the mRNA • Each codon codes from only on specific Amino Acid

13. 1 codon for 1 amino acid

14. Translation From mRNA => Proteins • mRNA comes from the nucleus to the Ribosome • At the Ribosome, the code of mRNA nucleotides is translated into the language of Protein amino acids using tRNA

15. tRNA • RNA molecules that helps build proteins • One end has an amino acid attached • One end has an anitcodon • Series of 3 nucleotides on the tRNA • Match with the mRNA codons • The amino acid is specific to the anticodon

16. Translation • mRNA enters the ribosome • Always starts with AUG on mRNA • tRNA from the cytoplasm attaches to the mRNA • Amino acid attached to tRNA is dropped off • The next tRNA with the matching anitcodon to the next codon enters the ribosome • The amino acid is dropped off and tied to the 1st amino acid…Until Stop Codon.

17. tRNA Ribosome Amino Acid

18. What is the Protein? • The series of Amino Acids created in translation • The order of amino acids determine the protein • Change the amino acids, you change the protein

19. Transcription and Translation Ex. • DNA Sequence • TACATACGCTTT • Complementary RNA • AUGUAUGCGAAA • Amino Acid Sequence • Met-Try-Ala-Lys

20. Transcription and Translation Ex. • DNA Sequence • TACATACGCTTT • Complementary RNA • AUG/UAU/GCG/AAA • Amino Acid Sequence • Met-Try-Ala-Lys

21. Mutations • Occur when DNA is replicated during the cell cycle • substitutions • deletions • insertions

22. Base Substitution • One DNA nucleotide is changed • May or may not cause a change in the protein • No change = silent mutation • Could change amino acid, and therefore the function of the protein

23. Silent Mutation • Original DNA Sequence • TACATACGCTTT • Complementary RNA • AUGUAUGCGAAA • Amino Acid Sequence • Met-Try-Ala-Lys • Mutated DNA Sequence • TACATGCGCTTT • Complementary RNA • AUGUACGCGAAA • Amino Acid Sequence • Met-Try-Ala-Lys

24. Silent Mutation • Original DNA Sequence • TACATACGCTTT • Complementary RNA • AUG/UAU/GCG/AAA • Amino Acid Sequence • Met-Try-Ala-Lys • Mutated DNA Sequence • TACATGCGCTTT • Complementary RNA • AUG/UAC/GCG/AAA • Amino Acid Sequence • Met-Try-Ala-Lys

25. Mutation: Change in Protein • Original DNA Sequence • TACATACGCTTT • Complementary RNA • AUGUAUGCGAAA • Amino Acid Sequence • Met-Try-Ala-Lys • Mutated DNA Sequence • TACACACGCTTT • Complementary RNA • AUGUGUGCGAAA • Amino Acid Sequence • Met-Cys-Ala-Lys

26. Mutation: Change in Protein • Original DNA Sequence • TACATACGCTTT • Complementary RNA • AUG/UAU/GCG/AAA • Amino Acid Sequence • Met-Try-Ala-Lys • Mutated DNA Sequence • TACACACGCTTT • Complementary RNA • AUG/UGU/GCG/AAA • Amino Acid Sequence • Met-Cys-Ala-Lys

27. Base Insertion & Deletion • Adding or taking away of nucleotides • Will change the overall order of the amino acids, and therefore the Protein will change

28. Mutation: Change in Protein • Original DNA Sequence • TACATACGCTTT • Complementary RNA • AUG/UAU/GCG/AAA • Amino Acid Sequence • Met-Try-Ala-Lys • Mutated DNA Sequence • TACAGTACGCTTT • Complementary RNA • AUG/UCA/UGC/GAA/A • Amino Acid Sequence • Met-Ser-Cys-Glu

29. Mutagens • What causes mutation • UV light • X-rays • Chemicals

30. DNA => Protein