DNA & Biotechnology ppt

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23 Οκτ 2013 (πριν από 3 χρόνια και 9 μήνες)

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DNA& Biotechnology

I. What is DNA?


D
eoxyribo
n
ucleic
a
cid


Polymer


Made of long chains of nucleotides


Phosphate group, sugar, & a nitrogen base


4 bases: C, G, A, T


C


G, G


C


A


T, T


A


Bases held together by hydrogen bonds




1

What is the structure of DNA?


2 strands running opposite each other


Sides are alternating
deoxyribose

sugar & a
phosphate molecule

-

N
-
bases are connected to the sugar









Form a twisting ladder, double helix

2

3

DNA’s job


DNA is transcribed into RNA which codes for
amino acids and makes proteins


Not all DNA codes for proteins


Coding sequences = exons


Noncoding parts = introns


RNA splicing trims out introns

4

p. 14
-
16 of NG, 30
-
1

Where is DNA found?


Coiled up

making chromosomes


Found inside the nucleus of cells

5

p.6
-
7 NG

Biotechnology


The study & manipulation of living things or
their component molecules, cells, etc.


biologycorner.com

Early biotech


Planting crops


Breeding animals to get specific traits


Using yeast to turn


Fruit juice into wine


Malt and hops into beer


Making bread rise


Using bacteria to turn milk into yogurt and
cheese


From Amanda Noller via
Pamela Peters, from Biotechnology: A Guide To
Genetic Engineering. Wm. C. Brown Publishers, Inc., 1993.



Current uses of biotech


Amplifying DNA to see it


Sequencing genomes


Gene splicing


Recombinant DNA/ Transformation


Creating effective medicines


Genetic Engineering


Cloning


Stem Cell Research


And so much more…


http://
www.iptv.org/exploremore/ge/what/insulin.cfm



From Amanda
Noller

via
Pamela Peters, from Biotechnology: A Guide To Genetic Engineering. Wm. C. Brown
Publishers, Inc., 1993

Isolating & manipulating DNA


Why?


Changing DNA nucleotides can alter proteins


Making medicines/hormones ex: insulin p.64


http://
www.youtube.com/watch?v=tJP_6nAPES4





chemicalconnections.org


Chromatography


a
set of techniques used to separate different
compounds.




Uses: isolating
new compounds,
analyzing
subtle differences between different
samples
,
and even in the sequencing of DNA.


Paper chromatography


stationary
phase

(a solid, or a liquid supported on a solid)


mobile
phase

(a liquid or a gas
).



The mobile phase flows through the stationary phase and
carries the components of the mixture with it
.



Different components travel at different rates
.



In
paper chromatography, the stationary phase is
a uniform
absorbent paper. The mobile phase is a suitable liquid solvent
or mixture of solvents.


R
f

values



Some
compounds in a mixture travel almost as far as the
solvent does; some stay much closer to the base line.


The
distance travelled relative to the solvent is called the
R
f

value. For each compound it can be worked out using the
formula
:


R
f

=
distance traveled by compound


distance traveled by solvent


For example, if one component of a mixture travelled 9.6 cm
from the base line while the solvent had travelled 12.0 cm,
then the
R
f

value for that component is
: 9.6/12 = 0.8


Gel electrophoresis


Separation technique


Visual way to see the pieces of DNA


Uses electrical impulses to pull the DNA
through a matrix like
jello

(called
Agarose
)


DNA in negatively charged, so it moves
towards a positive pole and away from the
negative


Separated by size, shape, & charge


http://www.dnalc.org/resources/animations/gelelectrophoresis.html



The cut DNA is mixed with blue dye and
loaded into a gel


6


DNA moves towards positive end (due to the
negative charges of the phosphates)


The dye moves faster than the smallest DNA
fragments


Smaller the fragments the faster they move


7

Using a
micropipetter


http://
www.youtube.com/watch?v=uEy_NGDfo_8



Set desired volume by turning the dial


Max volume is on top of pipette


Put sterile tip on from box


To load sample, press down until 1
st

stop


Release button to draw up sample


To release sample into container, push down on button, past
the 1
st

stop


Withdraw pipette from container before releasing the button


PCR



P
olymerase
c
hain
r
eaction


Used for forensics, medicine, research, and
more


Amplifies

small sections of DNA to get LOTS of
DNA


PC
R

8

What you need


DNA
-

you need something to copy!


Taq polymerase
-

copies the DNA


Primers
-

get the polymerase going


dNTP
-

the As, Ts, Cs, and Gs


buffered (pH controlled) tube of water


thermocycler


thermocycler

Taq polymerase

10


11

12

13

In the thermocycler…

1.
Heat to 95ºC (Denature)


DNA denatures into its two strands


2.
Cool down to 58ºC
-

65
°
C (Annealing)


Primer sequences stick to the template


3.
Heat to 72ºC (Synthesis)


Taq

polymerase attach at the primer and make a
complimentary copy of the DNA

4.
Repeat



Start with one copy


One copy, one cycle
-

2 copies


2 copies, one cycle
-

4 copies


4 copies, one cycle
-

8 copies


Typical runs include between 25
-
35 cycles


Finish with billions of identical copies of the original
DNA fragment



http://learn.genetics.utah.edu/content/labs/pcr/


Sources for pictures


1. http://www.scq.ubc.ca/a
-
monks
-
flourishing
-
garden
-
the
-
basics
-
of
-
molecular
-
biology
-
explained/


2.


3.
http://biolibogy.com/chemistryoflife.html


4.http://publications.nigms.nih.gov/thenewgenetics/chapter1.html


5.http://publications.nigms.nih.gov/thenewgenetics/chapter1.html#dnastr


6
-
9. Amanda Noller’s Biotechnology ppt


12.
http://andrew.cmu.edu


13.
http://coloradoindependent.com