1. DNA Deoxyribonucleic Acid
By Diana Bivens

2. What is DNA? DNA is found in the nucleus
contains all genetic information
controls protein production
Living things are made up of proteins
All actions are controlled by proteins called enzymes
is made up of nucleotides

3. DNA Structure Nucleotide Sugar molecule Phosphate group
deoxyribose
Phosphate group
One of 4 Nitrogen bases
Adenine (A)
Guanine (G)
Cytosine (C)
Thymine (T)

4. DNA Structure Phosphates and sugars form backbone of the chain
strands are held together by complimentary nitrogen bases with a Hydrogen bond
double helix shape
Discovered by James Watson
and Francis Crick using x-rays made
Rosalind Franklin

5. Complimentary nitrogen bases are joined by a Hydrogen bond and form the rungs of a DNA ladder
Adenine (A) always pairs with Thymine (T)
Guanine (G) always pairs with Cytosine (C)

6. Nucleotide Sequences ALL organisms contain the same DNA structures
The sequence determines the characteristics of an organism
Similar organisms share similar sequences

7. Replication DNA must be copied before cells divide
strands unzip (Hydrogen bonds break)
Free floating nucleotides bond to open strands
A to T
C to G
sugars and phosphates from adjacent nucleotides bond together
Result: two new DNA molecules, each identical to each other

8. http://highered. mcgraw-hill

9. Interesting fact
The total length of DNA present in one adult human = nearly 70 trips from the earth to the sun and back.

10. RNA vs. DNA ribonucleic acid vs. deoxyribonucleic acid
Single strand
Sugar : ribose
Nitrogen bases
Adenine
Cytosine
Guanine
Uracil
Double stranded
Sugar: deoxyribose
Nitrogen bases
Adenine
Cytosine
Guanine
Thymine

11. 3 types of RNA mRNA: carries the DNA code to the ribosomes
rRNA: RNA found within ribosomes
tRNA: RNA that transport amino acids for construction of proteins

12. Transcription Transcription: the making of mRNA from a portion of DNA
DNA molecule unzips
Free RNA nucleotides pair with nucleotides on DNA strand (Adenine w Uracil/Cytosine w Guanine)
Newly made mRNA breaks from DNA
DNA “re-zips”
mRNA travels from nucleus to ribosomes in cytoplasm

13. http://highered. mcgraw-hill

14. Codons Nucleic acids are grouped in 3’s called codons
DNA codon: AAA will be transcribed into an mRNA codon: UUU
****UUU codes for the amino acid Phenylalanine

15. The Genetic Code

16. The Genetic Code 20 different amino acids 64 possible codons
Several different codons can code for one type of amino acid
Ex. UUU and UUC : phenylalanine
Some codons trigger the beginning and end of protein synthesis (start and stop/terminator codons)
Ex. AUG: start codon / UAA: stop codon

17. Translation Translation: converting mRNA into a protein
A ribosome attaches to mRNA
tRNA carries amino acids to mRNA
anticodons on tRNA pair with mRNA codons ex. UAC (tRNA) – AUG (mRNA)
Ribosome slides down mRNA pairing tRNA and attached amino acid to complementary mRNA
Adjacent amino acids bond together
A protein is assembled

18. http://www. teachersdomain. org/resource/lsps07. sci. life. stru

19. Mutations
Mutation: any change in the DNA code that changes the protein it codes for
Mutations in sex cells may result in
death of embryo
A structural or functional problem
(rarely) a protein that improves function or structure
Mutations in sex cells are passed to offspring

20. Mutations Mutations in body cells may cause
Cells to function improperly
Uncontrolled cell division
Body cell mutations are NOT passed to offspring

21. Types of Mutations Point mutation: a change in a single nitrogen base
AUG-AAG-UUU-GGC
AUG-AAG-GUU-GGC
UUU: phenylalanine
GUU: valine
*a change in an amino acid in a sequence changes the protein it codes for

22. Types of mutations
Frameshift: a single nitrogen base is added or deleted, shifting the reading of the RNA sequence
AUG-AAG-UUU-GGC
AUG-AAU-GUU-UGG (insertion of U)
AUG-AGU-UUG (deletion of A in the second codon)

23. Chromosomal Mutations
Deletion: part of a chromosome is left out
Insertion: part of a chromatid breaks off and attaches to its sister chromatid
Inversion: part of chromosome breaks off and reinserts backwards
Translocation: part of a chromosome breaks off and attaches to another

24. Causes of Mutations Radiation Medications UV radiation from the sun
X-rays
Gamma radiation in nuclear reactors
Medications
Accutaine (acne medication)
Thalidomide (anti-nausea)

25. Causes of Mutations Other chemical agents Asbestos Cyanide
Formaldehyde
*anything that causes a mutation is called a mutagen