1. Chapter 12 DNA: The Molecule of Heredity

2. DNA Deoxyribonucleic acid (Genes) is found in nucleus.
Rosalind Franklin produced X-ray diffraction pictures of DNA.
Wilkins (Her lab partner) shared Franklin's data, without her knowledge, with Watson and Crick, at Cambridge University, ultimately publishing the proposed structure of DNA in March 1953.
Watson & Crick were given credit for discovering the DNA structure. The 1962 Nobel Prize was awarded to Maruice Wilkins, Francis Crick, and James Watson for the discovery of DNA's double helix.

3. DNA All organisms contain DNA made up of nucleotides
DNA determines an organism’s traits & direct protein production
Enzymes are proteins that control all chemical reactions of an organism

4. DNA is arranged in a double helix (twisted ladder)
DNA is a polymer made up nucleotides
Nucleotides are made up of
nitrogen base
phosphate
simple sugar

5. DNA G C T A
Purines 2 loops A & G
Pyrimidines1 loop T & C

6. The backbone (sides) of the ladder is made up of deoxyribose sugar and phosphoric acid (phosphate).
There are four nitrogen bases ATGC
Complementary base pairs
Adenine - Thymine
Guanine - Cytosine
These bases are held together by hydrogen bonds

7. DNA Replication DNA is replicated during interphase
An enzyme breaks the hydrogen bonds between the nitrogen bases
(Untwist the DNA molecule, unzipping bonds)
Free nucleotides are bonded to original strand by a different enzyme
Replication
4 DNA
1 Cell - 2 DNA
2 cells 2 DNA

8. DNA Replication Results in…
two identical strands of DNA
Each ½ the original (or parent nucleotides)
and ½ a complementary (or new nucleotides).

9. DNA vs. RNA DNA RNA # of Strands 2 1 Type of Sugar Ribose
Deoxyribose
Ribose
Type of Bases
ATCG
AUCG
Uracil

10. From DNA to Protein
Ribonucleic acid - used to get the genetic code from DNA translated into a Protein

13. DNA to Protein

14. From DNA to RNA - Transcription
In the nucleus, enzymes make an RNA copy of a portion of a DNA strand.
This results in a single strand of mRNA

15. From DNA to RNA
mRNA (messenger RNA) carries this copy of the code for making proteins out into the cytoplasm to the ribosomes.
Ribosomes are made partly of ribosomal RNA ( rRNA)

16. From DNA to RNA - translation
The mRNA attaches to the Ribosome.
Transfer (tRNA) Translates the code on the mRNA by using an Anticodon.
The anticodon matches the codon and brings the correct Amino Acid.

17. From DNA to RNA – protein synthesis
The amino acids bond together with peptide bonds and form a protein
The proteins form anything from digestive juices to muscles

18. RNA CODE = CODONS
DNA codes for 20 amino acids (AA) that make up all of our proteins.
3 nitrogen bases (called the codon) represent one amino acid
61 of the 64 triplet codes represent the 20 amino acids.
Some codons are start and stop codons
Genetic code is universal (at least every living thing we know of).

19. Codons are how the RNA Makes Proteins
                                        

20. Amino Acid Chart of Codons

21. The Decoder Ring 

22. DNA to Protein

24. Mutations- mistakes or changes in genetic material
Gene mutations- changes in one or more nucleotides
Chromosomal mutations- changes in number or structure of chromosomes
Sex cell mutations result in the entire offspring with that change in code
Body cell mutation affects that body part
Many, if not most, mutations are neutral, meaning that they have little or no effect

25. Gene Mutations THE CAT ATE THE RAT HER BAT ATE THE BUG
Normal Code
THE CAT ATE THE RAT
THE CAP ATE THE RAT
THE CA-A TET HER AT
THE CAR TAT ETH ERA T
THE EHT ETA TAC RAT
HER BAT ATE THE BUG
HER BAT ATE THE RAT
Substitution
Point mutation
Deletion
Frame shift
Mutation
Insertion
Inversion
Translocation

26. Chromosomal Mutations
Nondisjunction – the tetrads fail to disconnect during anaphase I of Meiosis
Polyploidy is a condition in which an organism has extra sets of chromosomes

27. 12-4 Mutations
12–4 Mutations

28. Gene Regulation
Operon- a group of genes that operate together as a functioning unit of DNA including:
an operator
a common promoter
and one or more structural genes,

29. Gene Expression

30. RNA Editing
Many eukaryotic genes have a sequence called the TATA box that helps position the polymerase just ahead of the sequences of nucleotides transcribed into mRNA
When RNA molecules are formed, introns and exons are copied from DNA.
introns are not involved in coding for proteins
exons are the DNA sequences that code for proteins are called.

31. RNA splicing

32. Development and Differentiation
As cells grow and divide, they undergo differentiation, meaning they become specialized in structure and function.
Hox genes control the differentiation of cells and tissues in the embryo.