Transcript Chapter 9 – Genetically Modified Organisms

Chapter 9 – Genetically Modified
Organisms
pp. 194-219
Gene Expression
• Gene Expression:
Converting a gene
(section of DNA) into a
protein
– Example: Allele on a
chromosome to a trait
Protein Synthesis-Cooking Analogy
https://www.youtube.com/watch?v=DP2Z26P_Jr0
Creating mRNA
Transcription: Copying of DNA gene into RNA
Events of Creating mRNA
•
•
•
On the DNA, you have
a promotor sequence
RNA polymerase
(enzymes that link RNA
nucleotides) binds to
the promoter and
creates RNA
RNA polymerase goes
down the DNA and
makes an RNA copy
Protein Synthesis
Translation: mRNA is used to link amino acids
in a specific order and length
Events of Synthesizing Protein
• Messenger RNA
[mRNA] from the
nucleus is transported
to the ribosome
• Transfer RNA [tRNA]
carries an amino acid &
attaches to three bases
on the mRNA called a
codon
• Another tRNA with an
amino acid attaches to
a codon
• Amino acids are linked
together
Review of Transcription & Translation
https://www.youtube.com/watch?v=DuHAMkgT6B8
Synthesizing Protein & the Genetic Code
• All organisms use the
same code
• The amino acid
coded for by a
particular codon can
be determined using
the genetic code
• What is the
relationship between
the genetic code and
genetic modification?
Mutations & the Genetic Code
Why do some mutations cause problems while
others don’t have an effect on the overall health
of an individual?
Effects of Mutations
• Some mutations cause the same amino acid to
be produced
• Some mutations cause a change in the shape or
length of the protein resulting in abnormal
function
Cells & Gene Expression
How is Gene Expression Regulated?
1. Increasing transcription with proteins that
stimulate RNA polymerase binding
2. Varying time DNA spends its uncondensed,
active form
3. Altering the mRNA life span
4. Slowing down/speeding up translation
5. Affecting the protein life span
Cloning a Gene
1. Remove the gene from the chromosome
2. Insert the gene into the bacterial plasmid
3. Insert the recombinant plasmid into a
bacterial cell
•
http://highered.mheducation.com/sites/0072556781/student_view0/chapter14/animation_quiz_1.html
Genetic Modification
• Examples
– http://www.mnn.com/green-tech/researchinnovations/photos/12-bizarre-examples-ofgenetic-engineering/mad-science
– https://www.youtube.com/watch?v=k7-ofCWJiUg
Genetic Modification
Pros
• Crops can make farms
more productive
• Crops can taste better
• Crops can have longer
shelf lives
• Crops can have more
nutrients
• Hope to cure diseases
and save lives
Cons
• Crops encourage
agribusiness
• Animals & crops may
cause health problems
• Crops may have adverse
environmental effects
• Low genetic diversity may
prevent adaptation to the
environment
• Unethical genetic
modification in humans