miscoded mRNA, mRNA mutations, frameshift mutation, base-pair substitutions, missense mutation, nonsense mutation, silent mutation, mutagens, uv light mutagen, nitrous acid mutagen, base analog mutagens

1. Describe: gene alteration b.stev

2. chromosomes may alter a b n o r m a l ly - this is said to be a: mutation > It causes miscoded mRNA mRNA codes for proteins that gives functions to the bacteria’s processes, thus alteration to this changes how the bacteria can operate correctly some have little effect/ others, contained within codons that would aid survival of the bacteria: - defence toxin production against competition - digestion enzyme change to the environment OR various purposes that effects their abilities (Campbell N. A, Reece J. B, 2005)

3. A U G A A G U U U G G U U A A Met Lys Phe Gly STOP U instead of a C Gly CODONS : GGU GGC GGA GGG

4. MISSENSE MUTATION: makes an amino acid, though the specific amino acid that was wanted within the sequence of the mRNA has changed A U G A A G U U U A G U U A A Met Lys Phe Ser STOP A instead of a G change in the amino acid

5. NONSENSE MUTATION : codon changes to the codes for a STOP codon Results: a shorter protein is made that is usually non-functional to the bacteria A U G U A G U U U G G U U A A Met STOP U instead of A (Campbell N. A, Reece J. B, 2005)

6. HAS a disastrous effect as it causes the sequence to become,’ out of line ,’ & as such results in extensive missense mutations RESULTS: proteins that are probably non-functional and/ or prematurely terminate in sequence INSERTION/ DELETION OF PAIRS

7. A U G A A G U U U G G U U A A Met Lys Phe Gly STOP A G INTENDED SEQUENCE insertion

8. mutagens UV light - causes thymine dimers in chemical bonding: DNA RESULTS: inability to insert correct bases when transcribed in process to the mRNA NOTE: this is how UV light can be used to kill bacteria Chemical OR Physical agent that causes a mutation (Pommerville J.C, 2004)

9. A C A A C C T G T T G G normal DNA A C A A C C T G T T G G abnormal DNA UV light: chemical bonding change

12. other chemicals effect DNA in some way ie: benzopyrene (in soot) aflatoxin heavy smoke Different effects (Pommerville J.C, 2004)

13. Bibliography Campbell N. A, Reece J. B. (2005). Biology (7th ed.) . San Francisco: Benjamin Cummings Pommerville J.C. (2004). Alcamo’s – Fundamentals of Microbiology (7 th ed.). Massachusetts: Jones and Bartlett.