2 8 Mutation

1. Convert the following mRNA strand into DNA:

…CUGACGUACG….

2. Take the following DNA strand through Central Dogma and produce the protein:

GACATACTCAACTGCAATT

Convert the following mRNA strand into DNA:

…CUGACGUACG… GACTGCATGC

Take the following DNA strand through Central Dogma and produce the amino acid chain:

GACATACTCAACTGCAATT CUGUAUG-AGU-UGA-CGUUAA Met- Ser-Stop

DNA and DNA replication (Mon)Transcription (Wed)CSI Las Vegas (Thu)Translation and Transcription

Practice (Fri)

B1B2B3B5

A mutation is a change in DNA sequence (order of nucleotides).

Mutations are important because they increase genetic variation.

Mutations can be good as well as bad.

Ex: A Protein to run fasterEx: A protein that causes Sickle Cell

Anemia

A mutagen is something that causes a mutation.

Ex: radiation, chemicals, high temp.

There are 2 main types of gene mutations. Point mutations Frameshift mutations

Point mutation-a change in one base pair in a DNA sequence.

Example: AUG=Met AAG=Lys

A point mutation may cause an amino acid to change, which will change the structure of the protein being made.

We call this a MISSENSE mutation

Normal

Point mutation

mRNA

ProteinStop

Stop

mRNA

Protein

Replace G with A

If the point mutation results in the same amino acid produced, we call this a SILENT mutation

AGU AGC SER SER

Frameshift mutation- adding or deleting nucleotides to a DNA sequence.

A frameshift mutation is much worse than a point mutation because it causes the entire sequence to be thrown off

A mutation the ends in an early stop codon is called a nonsense mutation.

DNA: THE CAT ATE THE HAT

We get: HEC ATA TET HEH AT

Delete this T

mRNA

Protein

Frameshift mutation

Is this a point mutation or a frameshift mutation?

It’s a point mutation because only one nucleotide changed!

THE DOG BIT THE CAT

THE DOG BIT THE CAR

Point or frameshift?

Point!

THE DOG BIT THE CAT

THE DOB ITT HEC AT

Point or frameshift?

-frameshift