Genetic Mutations Genetic Expression & Engineering - GertzScience

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.


DNA

PROTEIN
CODE

CELL
FUNCTION

DNA

RNA

Protein

Transcription (nucleolus)

Translation (
ribosomes
)

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

DNA

Code/Gene

Nerve cell
protein

Nerve cell

function

Liver cell
protein

Liver cell

function

Genes are expressed/transcribed when
the cell needs it.

Each cell expresses different parts of the DNA.

WALL

MALL

MAUL

HAUL

?

?

ATTTCGAGCCGTAAGC

•
Original code

ATTTCGAGC
G
GTAAGC

•
One
-
nucleotide change

DNA

•
Changes in DNA code/Sequence

PROTEIN

•
Changes protein ( shape or different
protein)

FUNCTION

•
Abnormal cell function


Point mutations


single nitrogen base change

▪
silent mutation

▪
no amino acid change

▪
redundancy in code

▪
missense

▪
change amino acid

▪
nonsense

▪
change to stop
codon

Complete the video guide while watching



http://www.youtube.com/watch?v=2CsgXHd
WqVs



http://www.youtube.com/watch?v=9UpwV1t
dxcs


What kind of mutation?

Missense
!


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?

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




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


Plasmids used to insert new genes into bacteria

gene 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