Today we review the structure of DNA and it’s history and replication using PowerPoint and hands on activity

Today we will understand the common mechanisms of protein synthesis

The “code” of the chromosome is the SPECIFIC ORDER that bases occur.

A T C G T A T G C G G…

http://www.youtube.com/watch?v=8kK2zwjRV0M&feature=player_detailpage

The genetic code is a sequence of nucleotides in the __________ of eukaryotic cells.

There are two polymers of nucleic acids, _____ and ______.

Maurice Wilkins & Rosalind Franklin◦X-ray diffraction ◦DNA must be a some type of spiral

(helix)◦DNA’s diameter is constant and stable

James Watson & Francis Crick◦Created the first accurate model of DNA◦Won the Nobel Prize

DNA is a double helixDNA contains four nucleotide bases: ◦adenine (A) ◦cytosine (C) ◦guanine (G)◦thymine (T)

The bases form the “rungs” on the DNA ladder by complementary pairing

A == TC == GT == AG == CA == TT == A

Sugar-phosphate backbone

Replication = Duplication◦Happens in the S phase of Interphase◦Must replicate before mitosis or meiosis

I Part of the double helix is unwound Enzyme stitches pieces together later

How does DNA replicate?

DNA encodes the information to make RNA.........and RNA molecules function together to make protein

DNA is "transcribed" or re-written into RNA in a very complicated process called transcrption.

Simply stated, during transcription, one gene (DNA) is 're-written' into an RNA in the nucleus.

During translation, the mRNA transported to the cytoplasm is "de-coded" or "translated" to produce the correct order of amino acids in a protein.. Translation requires numerous enzymes.

The Three RNAs (mRNA, tRNA, and rRNA) all work together to turn the information in DNA into a beautiful, 3-dimestional protein

A length of DNA on a chromosome May be in several parts

◦Exon – the expressed parts of the DNA sequence

◦Intron – the intervening, “junk DNA”, not expressed

Parts are cut, put together and then used to make RNA and proteins