Monday, November 29, 2010

DNA



Claire 11/29/10

AZT- has a shape similar to T nucleotide in DNA and binds to the viral enzyme instead of T. Therefor, it blocks spread of HIV virus

Griffith- found "Transforming Factor"-killed harmful bacteria with heat, mixed with living cells of nonharmful bacteria, nonharmful bacteria became harmful. "Transforming Factor" was inherited by originally unharmful bacteria(which changed)

Hershey and Chase- DNA of a virus that is injected into host cells reproduces new viruses.

Franklin (& Wilkins)- Found helical shape (spins around itself) of DNA with x-ray crystallography

Watson and Crick- model of DNA, base pairing(what bonds with what), double helix structure
Earn Nobel Prize with Wilkins in 1962--Franklin died and was not included because they didn't want to give to this award to a female

Structure
Double Helix


















nucleotide=1 sugar, 1 phosphate, 1 base

nucleotide=monomer
DNA=polymer
nucletides change to DNA through d
ehydration synthesis


Nucleic acid-"polynucleotide"
4 Nucleotides(bases): A=Adenine C=Cytosine T=Thymine G=Guanine

G bonds with C
A bonds with T
form hydrogen bonds with each other

DNA has three rings across, A and G have 2 rings and C and T have one. A and G can't bond because there would then be 4 rings across

T and C=pyrimidines(single ring)
A and G=purines(double ring)

N bases protrude from sugar
sugar-phosphate backbone
sugar=5 carbon ring=deoxyribose(missing oxygen atom)

1 nucleotide= nitrogen base, sugar, phosphate
nucleotides joined by covalent bonds between sugar and phosphate














Chargaff- in DNA, amount of A=amount of T, amount of G=amount of C (proves base pairing)

Sequence of bases in DNA determines kind of gene on chromosome


DNA Replication

occurs in nuclues
Parent DNA untwists, strands separate
N bases attach to complementary base (A to T, G to C)
2 Daughter DNA molecules-rewinds and formed












Polymerases- enzymes that make covalent bonds between nucleotides of new DNA strand
very unlikely to be paired incorrectly
DNA Polymerase and other protiens can repair damaged DNA

DNA harmed by: UV rays, X-rays, viruses

Replication begins at origins(beginning)
goes in both directions-forming a bubble

bubbles can merge












genetic instructions are copied for the next generation

Beadle and Tatum- one gene produces one speacific enzyme/protien/polypeptide

Sections on DNA code for certain amino acids
20 amino acids total

triplet codes-codons(necessary)

G,T,C,A(4) * G,T,C,A (4)= 16 (not enough

G,T,C,A(4) * G,T,C,A (4)*G,T,C,A(4)=64 different triplets(more than enough)

Next Scribe:Bridget

4 comments:

  1. Hey Claire you had some amazing information on this post. You did a great job summarizing the notes. I liked how you added the important people. Next time add some pictures to make it better.

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  3. You had a lot of good information :) it helped me understand better.

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  4. I also think that you had good information. I also thought that it was summarized really well and the fact that you highlighted the most important information with different colors. This helps especially when people skim through this info and it will show them the parts they should read.

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