1. DNA RNA Protein Synthesis
Chapter 9 & 10
DNA
RNA
Protein Synthesis

2. DNA DNA- deoxyribo nucleic acid Structure of DNA:
DNA is a genetic molecule that contains all of the instructions to create an organism
Structure of DNA:
Double helix “spiral ladder”
Discovered by James Watson & Francis Crick

3. Nucleotides Nucleotides are the basic subunits that make up DNA
Nucleotides consist of 3 molecules: a phosphate group, a sugar(ribose), and a nitrogen base
Diagram:
5-carbon Sugar

4. DNA Bases There are 4 different DNA Bases: A: Adenine T: Thymine
C: Cytosine
G: Guanine

5. DNA Base Pairs DNA bases always pair in the same way
A : T - adenine pairs with thymine
C : G - cytosine pairs with guanine

6. DNA Strand: A T - fill in the corresponding DNA bases G C T Remember:
C:G

7. DNA Replication DNA replication is the process of copying DNA
It occurs during S-phase of the cell cycle
Makes 2 exact copies of a cells DNA

8. Steps in DNA Replication
The two original DNA strands separate
- the DNA-helicase enzyme separates the two DNA strands
Diagram:
DNA strand
Helicase Enzyme

9. Steps in DNA Replication
2) DNA-polymerase enzyme forms two new DNA strands to match the original strand
Diagram:
Replication Fork!
new DNA!
original DNA strand
new DNA!

10. Steps in DNA Replication
3) Two DNA molecules are formed that are identical to the original DNA molecule!!!!!!
Diagram:

11. DNA Mutations
Any change in the genetic code of an organism is a mutation
Mutations may have a small, large, or no effect on an organism
Mutagens:
- substances that can cause mutations
Ex: toxic chemicals, UV radiation, nuclear radiation, extreme heat

12. DNA Mutations Deletion- 1 nuclotide is left out during replication
Insertion- 1 nucleotide is added during replication
Point Mutation- 1 nucleotide is substituted with another during replication

13. Chromosome Mutations Deletion- removal of a segment of a chromosome
Duplication- addition of a repeated DNA segment

14. Chromosome Mutations Inversion- reordering of genes on a chromosome
Displacement- attachment of DNA to a different chromosome

15. RNA RNA – ribo nucleic acid 3 Types of RNA: rRNA - ribosomal RNA
- used to make ribosomes
tRNA - transfer RNA
- used to make proteins
mRNA - messenger RNA
- used to send messages from
the nucleus to the cytoplasm

16. RNA Bases RNA uses Uracil(U) instead of Thymine(T)
RNA Base Pairs: A : U
C : G
AGU CAU GUG CAC UUA CAG AUC GCA

17. Transcription Transcription is used to make mRNA Steps:
1) DNA-Transcriptase “unzips” DNA
The two DNA strands unwind & separate
2) RNA-polymerase enzyme binds to DNA
3) mRNA is made by RNA-polymerase based on the genetic code of the DNA

18. Transcription Diagram

19. mRNA Composition mRNA has distinct segments called introns and exons
Introns- segments of RNA that do not code for proteins
Exons- sequences that do code for proteins

20. Reading the Genetic Code
Codons: a series of 3 nucleotides that code for an amino-acid
- each codon is used to create an amino-acid

21. RNA Codons
Codon A U G C

22. Translation Translation forms proteins from RNA Steps:
1) Ribosomes bind to mRNA in cytoplasm
2) tRNA carrying amino-acids attaches to the mRNA
3) Amino-acids from the tRNA begin to form a chain(polypeptide)
4) When the ribosome reaches the end of the mRNA it detaches
5) The polypeptide chain is complete, forming a protein

23. Translation Diagram

24. Overview of Protein Synthesis
DNA mRNA Protein
Transcription
Translation

25. Genetic Engineering
Genetic engineering is used to create organisms with specially designed genes & traits
Recombinant DNA- pieces of DNA combined from 2 different organisms

26. Gene Splicing

27. Uses of Recombinant DNA
Insulin- make bacteria produce insulin for human use to treat diabetes
Resistance- can put recombinant DNA into plants to make them resist diseases
Vaccines- can use recombinant DNA in animals to produce immunity to diseases

28. Cloning
Cloning is the production of organisms with identical genes

29. END OF CHAPTER 9&10 NOTES!!!