Transcript Dna text notes - BellevilleBiology.com

Chapter 12
Text book Notes
12-1
• TRANSFORMATION- process by which 1
strain of bacteria is altered due to the DNA
of another bacteria… (p 288)
• How did we find out that this happens…?
1928 Griffith: British scientist
• Prob? How do bacteria make people sick?
– Specifically the bacteria pneumonia…
• Materials: mice, syringe, diseased bacteria(A),
healthy bacteria(B)
• Results : (what do you think will happen- which
bcateria will kill the mice?)
Harmless
bacteria?
Mice lived
Bacteria A
Mice dies
Flamed
Bacteria A
Mice lived
Why?
Flamed
Bacteria A and
Bacteria B
Mice died
Why? The good
bacteria picked up the
DNA, from the dead
disease causing
bacteria, and it
became disease
causing too
12-3 RNA & Protein Synthesis
• Synthesis?
– DNA instruction is in code
• ATCCGGTTAAAGGTCCCTCTCTGATCC
CGTATTAAAGTCGATTGACGATGCAGT
GACGATGAAGTCGAAAACCGGTTGTG
TGCCAGTGGCAGTGATG
– Code controls the making of proteins
(which control traits: ex blood type, flower
color )
– QUESTION OF THE DAY:
• How can we decode that message?
Decode Message
• Message needs to go from nucleus to
ribosomes….
DNA vs RNA
DNA- deoxy, ribo, nucleic,
acid
RNA – ribo, nucleic, acid
Double strand
Single strand
Deoxyribose (sugar)
Ribose (sugar)
Nitogen Bases: ATCG
Nitrogen Bases: AUCG
JOB- instructions for all cells JOB: protein synthesis
(needed by body for growth
and repair)
Meet the RNA family …
• mRNA travels to ribosomes
• rRNA is present at the ribosomes
• tRNA- transfers the amino acids to the
ribosomes
Transcription
• Step 1: mRNA goes over to the DNA in
the nucleus, and finds the original strand
• Step 2: mRNA looks only for the section
that it needs to copy
• Step 3: mRNA finds the section and
copies it but in its own complementary
language
• Step 4: mRNA goes to Ribosome with
message
Translation
• Step 1: mRNA arrives at the ribosome,
and rRNA is already there waiting….
• Step 2: mRNA and rRNA show the section
of the code in codons in (mRNA language)
to all the present tRNA’s
• Step 3: the tRNA’s look at their
anticodons, and see which codons they
match. They will match their
corresponding codons with the right amino
acid.
• Step 4: After a bunch of amino acids line
up- proteins are made….
• http://www.youtube.com/watch?v=983lhh2
0rGY
• Video transcription and translation
• Video replication
• http://www.youtube.com/watch?v=hfZ8o9
D1tus&feature=related
12-4
• Mutations: change in the genetic material
• …. Now and again cells make mistakes in
copying DNA
2 types of Mutations
• Gene mutations
• Chromosomal mutations
Gene Mutations
• Occur on a single gene
• TAC GCA TGG AAT
• Code is read in 3 base
codons
• Thefatcatandratran- say?
3 types of gene mutations
•
•
•
•
•
Point Mutations occur at 1 spot
TAC GCA TGG AAT – original
Substitution?
Insertion?
Deletion ?
• TAC GCA TGG AAT – original
• Substitution
– TAC GGA TGG AAT
• Insertion
– TAC GGC ATG GAA T
• Deletion
– TAC GAT GGA AT
Which are the 2 worst kinds of
point mutations? Why?
• THE FAT CAT RAN – original
• Substitution
– THH FAT CAT RAN
• Insertion
– THE FAA TCA TRA N
• Deletion
– HEF ATC ATR AN
Which are the 2 worst kinds of
point mutations? Why?
• Changes message which changes the
amino acid that is made- wrong protein
made …
Chromosomal Mutations
• Changes in the …
– Number of chromosomes
• Down’s Syndrome
– Or structure of chromosome
•
•
•
•
Deletion
Duplication
Inversion
Translocation
See chrom. Mut. Chart
• http://www.pearsonsuccessnet.com/snpap
p/iText/products/0-13-1811185/ch12/sb7015a04.html
• Deletion- 1 section is deleted
• Duplication- 1 section is doubled
• Inversion- 1 section is reversed
• Translocation -part of one
chromosome breaks off and attaches
to another.
Mutations are good, bad or neutral
• Neutral
• Bad: cause dramatic changes in protein
structure… body cannot function properly
• Good.. Can create variability in species,
can be beneficial, if environment
– Ex- AIDS resistant gene
– Polyploidy (extra chromosomes)
• Banana and citrus fruits are larger and stronger