Genetic Mutations Genetic Expression & Engineering

twoeggfinnishΒιοτεχνολογία

14 Δεκ 2012 (πριν από 4 χρόνια και 11 μήνες)

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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.

Different

Genes

Different

Amino
acids

Different

Protein
structure

Different

Protein
Function

Different

Traits

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


Causes abnormal cell function


Point mutations


(most common)


single nitrogen base change


Only one nucleotide changes



silent mutation


no amino acid change
-
> no change


Why this happens?


-
>redundancy in code



missense


change amino acid
-
> change
structure and function



nonsense


changes 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

mutations


shift in the r
eading
frame


changes everything
“downstream”


insertions


adding base(s)


Deletions ( most
damaging)


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




Resistant lice already
existed before anti
-
lice
shampoo over
-
use.



You can’t tan
permanently!



Red light will not cause
direct mutations.



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