Download DNA, Proteins, and Biotechnology

DNA, Proteins, and Biotechnology
Mr. Nagel
Meade High School
Warm Up
DNA Replication
• Outline the process of DNA Replication. Include
enzymes and their functions.
IB Syllabus Statements
• 3.5.1
– Compare the structure of RNA and DNA.
• 3.5.2
– Outline DNA transcription in terms of the formation of an RNA
strand complementary to the DNA strand by RNA polymerase.
• 3.5.3
– Describe the genetic code in terms of codons composed of triplets
of bases.
• 3.5.4
– Explain the process of translation, leading to polypeptide formation.
• 3.5.5
– Discuss the relationship between one gene and one polypeptide.
http://click4biology.info/c4b/3/Chem3.5.htm
Nucleotide – Structure
Structure of DNA
Sense v. Antisense DNA
• Sense: mRNA
sequence exists
that matches it
• Antisense: DNA
Compliment
(usually copied
from)
• DNA strand 1
(5’3’): sense
• DNA strand 2
(3’  5’): antisense
• mRNA codon: sense
• tRNA anticodon:
antisense
Transcription
• http://users.rcn.com/jkimball.ma.ultranet/Bi
ologyPages/T/Transcription.html
– What are the steps?
– Are there any special modifications to the
mRNA after creation?
Transcription
• Moving from DNA to RNA
– Create a messenger (mRNA)
– Moves from the nucleus to
the cytoplasm
• Specifically the rough
ER (ribosomes)
– To be read as ‘blueprints’
for proteins
• Post-processing
– 5’ Cap; Poly-A tail; Intron removal [eukaryotes]
Video Time!
• http://www.hhmi.org/biointeractive/dna/ani
mations.html
Think…
• How many different words can you make
with one of these LETTERs (ATGC)?
• TWO LETTERs (ATGC)?
• THREE LETTERs (ATGC)?
• FOUR LETTERs (ATGC)?
Translation Overview
• Initiation
• Elongation
• Termination
Arming the tRNA
• Each tRNA is shaped differently
– Loop regions
• Shape is worked on by different
enzymes
• Enzyme attaches specific AA to tRNA
– Requires ATP
• Each AA has one or more tRNA molecules
– Degenerate code
Translation: How it works
• rRNA holds the mRNA and brings it
together with tRNA
http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/T/Translation.html
Transcription/Translation Activity
• Transcribe the following:
– TAC GCC CGA ATA TAT AAA ATT
• Translate the following:
– AUG GCC UGA
Warm Up
Translation
• In which direction
will translation
occur?
• What will the next
amino acid be in
the sequence?
• Name two places
in a eukaryotic cell
where translation
occurs.
Code Game
• There are multiple DNA
fragments hidden
throughout the room
(some with multiple
copies).
– Find the DNA fragments
and record them.
– Transcribe the mRNA
fragments.
– Use the Nagel-codon table
to decode the fragments.
• Once you do so, determine
what the original sequence
of DNA said (before
fragmentation)!
DNA Codes (Hidden)
•
•
•
•
•
1)
2)
3)
4)
5)
TAC TTT TCT
TAA TTA CTT
TAC AGG GCT
GGG TCC CAC
TGG CGG AAA ACT
Mutations
• Insertion or Deletion
– Frameshift Mutation
• Substitution
– Point Mutation
• Nonsense Mutation
• Silent Mutation
Warm Up
DNA
• Determine the strand of mRNA that is
transcribed from the strand below.
ATC CAG GTC AAG
• List three other molecules apart from mRNA that
are needed for transcription.
• What would the anticodons of the corresponding
four tRNA molecules be? Would they be
considered sense or anti-sense?
IB Syllabus Statements
•
•
•
•
•
•
•
•
•
•
•
•
•
4.4.1
–
4.4.2
–
4.4.3
–
4.4.4
–
4.4.5
–
4.4.6
–
4.4.7
–
Outline the use of polymerase chain reaction (PCR) to copy and amplify minute quantities of DNA.
State that, in gel electrophoresis, fragments of DNA move in an electric field and are separated according to their size.
State that gel electrophoresis of DNA is used in DNA profiling.
Describe the application of DNA profiling to determine paternity and also in forensic investigations.
Analyse DNA profiles to draw conclusions about paternity or forensic investigations.
Outline three outcomes of the sequencing of the complete human genome.
State that, when genes are transferred between species, the amino acid sequence of polypeptides translated from
them is unchanged because the genetic code is universal.
4.4.8
– Outline a basic technique used for gene transfer involving plasmids, a host cell (bacterium, yeast or other cell),
restriction enzymes (endonucleases) and DNA ligase.
4.4.9
– State two examples of the current uses of genetically modified crops or animals.
4.4.10
– Discuss the potential benefits and possible harmful effects of one example of genetic modification.
4.4.11
– Define clone.
4.4.12
– Outline a technique for cloning using differentiated animal cells.
4.4.13
– Discuss the ethical issues of therapeutic cloning in humans.
http://click4biology.info/c4b/4/gene4.4.htm
DNA Tech: PCR
DNA Tech: Restriction Enzymes
• Restriction Enzymes
– Cut like chemical scissors at various
recognized sequences
DNA Tech: Gel Electrophoresis
• Proteins or DNA travel through a gel
based on SIZE and CHARGE.
• Virtual Gel Electrophoresis
– http://learn.genetics.utah.edu/content/labs/gel/
DNA Profiling
Cloning (Genes or Organisms)
• Bacteria used for genes
– Cut and paste using restriction enzymes
• Egg cells with removed nuclei are used for
cloning entire organisms
– Moral or ethical ramifications?
DNA Sequencing
• Utilize ddNTPs to halt elongation
• Millions of strands of various lengths
Microarrays and Gene Therapy
• Microarrays are used to detect what genes
are activated at any given time
• Gene Therapy is when defective genes
are removed and replaced by working
ones, than reinserted into the host
Warm Up
DNA Revisited
• State the names of the structures listed above.
• State the name of the structure above that has
an anticodon.
• Explain why the process above is called
translation.
• How is translation terminated?
IB Syllabus Statements
•
•
•
•
•
•
•
•
•
•
•
•
•
4.4.1
–
4.4.2
–
4.4.3
–
4.4.4
–
4.4.5
–
4.4.6
–
4.4.7
–
Outline the use of polymerase chain reaction (PCR) to copy and amplify minute quantities of DNA.
State that, in gel electrophoresis, fragments of DNA move in an electric field and are separated according to their size.
State that gel electrophoresis of DNA is used in DNA profiling.
Describe the application of DNA profiling to determine paternity and also in forensic investigations.
Analyse DNA profiles to draw conclusions about paternity or forensic investigations.
Outline three outcomes of the sequencing of the complete human genome.
State that, when genes are transferred between species, the amino acid sequence of polypeptides translated from
them is unchanged because the genetic code is universal.
4.4.8
– Outline a basic technique used for gene transfer involving plasmids, a host cell (bacterium, yeast or other cell),
restriction enzymes (endonucleases) and DNA ligase.
4.4.9
– State two examples of the current uses of genetically modified crops or animals.
4.4.10
– Discuss the potential benefits and possible harmful effects of one example of genetic modification.
4.4.11
– Define clone.
4.4.12
– Outline a technique for cloning using differentiated animal cells.
4.4.13
– Discuss the ethical issues of therapeutic cloning in humans.
http://click4biology.info/c4b/4/gene4.4.htm
DNA Technology
Please discuss with a neighbor answers to the following:
What is it?
PCR
Restriction Enzymes
Gel Electrophoresis
(DNA Profiling)
Cloning
DNA Sequencing
DNA Microarrays
How is it used in
modern science?
Bioethics – Small Group
• The Case of Cats and Clones
– http://auth.mhhe.com/biosci/genbio/olc_linked
content/bioethics_cases/g-bioe-03.htm
– Read the case study and then answer the
questions in your small groups. Discuss your
responses in a respectful manner.
– Record your responses on the back of the
worksheet.
Bioethics – Self Study
• Given the advent of biotechnology, there
seems to be limitless possibilities (curing
genetic disorders, engineering our own
offspring, etc).
– At what point should a line be drawn?
– Should there be a line drawn at all?
– Who should establish those guidelines?