DNA (Gene) Mutations

1. DNA (Gene) Mutations

2. Often times, parts of DNA will have a base (or more) missing, added, or incorrect Can be caused by: errors in replication, transcription, cell division, or by external agents (like radiation) What is a gene mutation?

3. A mutation is any change in the Nucleic Acid (DNA/RNA) sequence. Any agent that can cause a mutation is a mutagen. What is a gene mutation?

4. Mutagens • Any agent that can cause a mutation • These are caused by factors in the environment such as: • Radiation (x-rays, UV, nuclear) • Chemicals • Extremely high temperatures • Biological agents such as HPV

5. Mutations occurs at a frequency of about 1 in every 1 billion base pairs Everybody has about 6 mutations in each cell in their body! How common are mutations?

6. Point Mutations Substitution Insertion w/ frameshift Deletion w/ frameshift Chromosomal Mutations Deletion Duplication Inversion Translocation The most common types of gene mutations are:

7. Substitution Normal DNA: CGA – TGC – ATC Mutated DNA: CGA – TGC - TTC DNA (Gene) Mutation What has happened in this mutation?

8. Normal DNA: CGA – TGC – ATC Mutated DNA: CGA – TGC - TTC DNA (Gene) Mutation *Adenine was accidentally replaced with thymine *What is this mutation called?

9. Normal DNA: CGA – TGC – ATC Mutated DNA: CGA – TGC - TTC Substitution What will happen to the amino acids?

10. Original DNA- ATC would code for : STOP • Mutated DNA of TTC would code for: Lysine

11. B. Insertion with Frameshift Normal DNA: CGA – TGC – ATC Mutated DNA: CGA – TAG – CAT - C DNA (Gene) Mutation What has happened in this mutation?

12. Normal DNA: CGA – TGC – ATC Mutated DNA: CGA – TAG – CAT - C DNA (Gene) Mutations *Adenine was inserted, causing the remaining DNA to shift to the right. *What is this mutation called?

13. Normal DNA: CGA – TGC – ATC Mutated DNA: CGA – TAG – CAT - C Insertion with Frameshift What will happen to the amino acids?

14. DNA (Gene) Mutation C. Deletion with Frameshift Normal DNA: CGA – TGC – ATC Mutated DNA: CGA – TCA- TC What has happened in this mutation?

15. DNA (Gene) Mutation Normal DNA: CGA – TGC – ATC Mutated DNA: CGA – TCA- TC *Guanine was removed,causing the remaining DNA to shift to the left *What is this mutation called?

16. Deletion w/ Frameshift Normal DNA: CGA – TGC – ATC Mutated DNA: CGA – TCA- TC What will happen to the amino acids?

17. Substitution or Point Mutation • THE DOG BIT THE CAR • THE LOG BIT THE CAR • THE DOG BIT THE CAT • THE DOG HIT THE CAR • THE HOG BIT THE CAR • THE FOG BIT THE CAR

18. Insertion Mutation • THE DOG BIT THE CAR • THH EDO GBI TTH ECA R

19. Deletion Mutation • THE DOG BIT THE CAR • THE OGB ITT HEC AR

20. Gene mutations • Point mutations • Change one nucleotide or just a few nucleotides in a gene • Examples: sickle cell anemia & cystic fibrosis • Frame-shift mutations • The reading pattern is displaced and “shifts” into new positions • Examples: duchenne Muscular Dystrophy

21. Frame shift mutations • The cat and the rat ran far. • The ca and the rat ran far. • The caa ndt her atr anf ar. t

22. Mutations: Changes in DNA • Disadvantages: • Abnormal, even lethal genes can be passed on to offspring • Advantages: • New, stronger genes can be passed on to offspring

23. Chromosomal mutations • Deletion = loss of all or part of a chromosome. • Insertion or Duplication = produce extra copies of parts of a chromosome. • Inversion = reverse the direction of parts of a chromosome. • Translocation = occurs when part of one chromosome breaks off and attaches to another different chromosome.

24. Chromosomal Mutations

25. DNA 5’ A T G C C T G A A T G A 3’ 3’ T A C G G A C T T A C T 5’ coding strand mRNA A UG C C U G A A U G A codons tRNA U A C G G A C U U A C U anti codons amino acids Met Pro Glu stop protein

27. The Central Dogma is Universal

28. The Central Dogma theory of Biology DNA → RNA →protein→ cell structure & function