Using a Codon Chart &Mutations

Today’s Goal: Review codons and anticodons and describe several types of mutations.

Quiz tomorrow over ch 12 and 13 material If good understanding of codon chart start with slide

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What do these codons code for?

1. UUA = ?2. AAG=?3. UUG=?

DNA to Amino Acid Sequence

DNA: TAC ACA CGA GGA GGG TCT AAA ATT

mRNA:

tRNA:

Amino acids:

Mutations

• A mutation is a change in structure of amount of genetic material of an organism.

• Genetic material is different from previous.• A small change in DNA may affect an amino

acid in the protein.• There maybe no, a positive effect, or a

negative effect from a mutation.

Mutagens

• Chemical / physical agents in the environmental that cause mutations. – No/little effect– Beneficial- “polyploidy” in plants to make stronger,

or adjust to changing environment– Negatively- sickle cell disease

Types of mutations• 1. Point – single nucleotide changes• Gene Mutations: single gene

– No mutation• ATG CCA TCG• Met pro ser

– Silent mutation• ATG CCT TCG• Met Pro Ser

– Missense mutation• ATG CAA TCG• Met Gln Ser

– Nonsense mutation• ATC CCA TCG• STOP

Chromosomal mutations: #/structure

• 2. Insertion – extra nucleotides are added • 3. Deletion – nucleotides are removed–No mutation• ATG CCA TCG•Met Pro Ser

– Frameshift mutation• ATG GCC ATC G•Met Ala Ile

Gene Mutations: Deletion, insertion, substitution

• Which 2 lead to a frameshift?

Other Chromosomal Mutations

• Original Deletion

• Original Inversion

• Original Translocation

• Original Duplication

A B C D E F

A B C D E F

A B C D E F

A B C D E F

A C D E F

A E D C B F

A B C J K L D E F

A B B D E FC

• Which of the following mutations would cause a more serious effect in the coding of UUG?

a)UUAb)CUAc)UAA