do now show a diagram of how you would split/ unwind the following base pairs of dna draw the two...
TRANSCRIPT
Do Now• Show a diagram of how you would split/
unwind the following Base pairs of DNA
• Draw the two new strands of DNA after replication
Do Now Answer
“Unzipped” Replicated: (original strand black, new
strand red)
12-3Protein Synthesis
Transcription and Translation
• If all the DNA in ten human nuclei were enlarged to a full-sized continuous ladder, it could reach more than 30 million miles, or from the earth to the planet Mars:
•
I. Gene Expression
A. Each DNA molecule carries
directions to make the organism
B. DNA is the blueprint for the sequence of amino acids that make up a protein
DNARNA Amino AcidsProteinsYOU!
How does DNA make proteins?
II. Transcription
A. DNA can NOT leave the nucleus
B. A copy of the DNA “recipe”
needs to be madeC. DNA copies itself into Ribonucleic
Acid (RNA)
III. mRNAA. The disposable copy of DNAB. It has the same structure as
DNA but Thymine is replaced by Uracil (A-U instead of A-T)
C. The copy leaves the nucleus with the protein “recipe” it copied from the DNA
D. It is called messenger RNA (mRNA) because it brings the message from the nucleus to the ribosomes
Transcription continued…• An entire strand of DNA is not transcribed into
RNA at once.– Small segments of DNA are transcribed to RNA that
code for specific genes
• IntronsIntrons – parts of the DNA sequence that do not code for any
gene
• Exons – parts of the DNA sequence that code for different
genes – Only Exons will be used to create RNA!
http://www.stolaf.edu/people/giannini/flashanimat/molgenetics/transcription.swf
IV. Translation
A. The recipe now has to be read or translated
B. The ribosome (rRNA) attaches and travels along the recipe strand
C. The recipe is read in groups of
3 bases called codons
D. The codons represent the order of the amino acids in the protein that is being created
E. Transfer RNA (tRNA)anticodons are complimentary to mRNA
F. Carry amino acids to ribosome where they are linked together to
form proteins
mRNA basesamino acidsprotein
(polypeptide)
• http://www.sciencenetlinks.com/interactives/protein.html
http://www.youtube.com/watch?v=4PKjF7OumYo&feature=related
http://www.youtube.com/watch?v=xc2wbIDfO7E
A.
CUU?
Leucine!
1. Fill in the complimentary DNA strand using base pairing rules
DNA
Completed strand
DNA
Fill in the correct mRNA bases by transcribing the bottom DNA code
Completed m RNA
Fill in the paired tRNA anti codons
Completed tRNA
Using the mRNA strand, translate the codons and find the correct amino acid
using the Codon table
http://www.darienps.org/teachers/otterspoor/notes/mrna.pdf
12-4 Mutations – see dittoI. Chromosomal: involves pieces of chromosomes – several bases
1. Deletion
2. Inversion
3. Translocation
4. Duplication
II. Point (gene) mutations – involves one or only a few bases
1. Frameshift – due to deletion or insertion – shifts entire code