Genetic MutationsGenetic Expression & Engineering

BI. 4c Students know how mutations in the DNA sequence of a gene may or may not affect the expression of the gene, or the sequence of amino acids in an encoded protein.

BI.4.d Students know specialization of cells in multicellular organisms is usually due to different patterns of gene expression rather than to differences of the genes themselves.

BI 5c Students know how genetic engineering (biotechnology) is used to produce novel biomedical and agricultural products.

What kind of information does DNA have?

DNA PROTEIN CODE

CELL FUNCTIO

N

How?-through Protein synthesis!

Transcription (nucleolus)

Translation (ribosomes)

One gene for one organism

All types of cells in a person’s body carry the same DNA .

What is genetic expression?

DNACode/Gene

Nerve cell protein

Nerve cell function

Liver cell protein

Liver cellfunction

Genes are expressed/transcribed when the cell needs it.

Each cell expresses different parts of the DNA.

Let’s take a moment to look at these words. With your elbow partner, come up with two new words by changing one letter from the previous word.

WALL

MALL

MAUL

HAUL ? ?

This change also happens in DNA.

ATTTCGAGCCGTAAGC•Original codeATTTCGAGCGGTAAGC•One-nucleotide change

What is a genetic mutation?

DNA •Changes in DNA code/Sequence

PROTEIN •Changes protein ( shape or different protein)

FUNCTION •Abnormal cell function

Mutations Point mutations

single nitrogen base change ▪ silent mutation▪ no amino acid change▪ redundancy in code

▪ missense▪ change amino acid

▪ nonsense▪ change to stop codon

Sickle Cell Anemia

Complete the video guide while watching

http://www.youtube.com/watch?v=2CsgXHdWqVs

http://www.youtube.com/watch?v=9UpwV1tdxcs

Only one nucleotide change causes Sickle cell anemia !

What kind of mutation?

Missense!

Mutations Frameshift

shift in the reading frame▪ changes everything

“downstream” insertions▪ adding base(s)

deletions▪ losing base(s)

Where would this mutation cause the most change:

beginning or end of gene?

Cystic Fibrosis (CF)

http://www.youtube.com/watch?v=VxhQAQYgrKY&NR=1

Are mutations passed on to children? Gametes/sex cell mutations Yes

Ex. Changes in egg and sperm cell genes due to chemicals

Somatic/body cell mutations No

Ex. Scars on your mother’s hand as a result of an accident

Changing genes artificially!

A Brave New World

Biotechnology Plasmids used to insert new genes into

bacteriagene we want

cut DNA with restriction enzymes

cut plasmid DNA

insert “gene we want” into plasmid...“glue” together with ligase

like what?…insulin…Human

Growth Hormone… healthy

genes Cut DNA?DNA scissors?

recombinant plasmid