The document discusses the structure and replication of DNA. It begins by explaining that DNA is a double helix composed of four nucleotide bases - adenine, cytosine, guanine, and thymine. The bases bond together in a complementary pairing between A-T and C-G. Replication of DNA involves unwinding the double helix and using enzymes to stitch new strands together. The document then describes how DNA is transcribed into RNA and translated into proteins, with mRNA carrying the genetic code from DNA in the nucleus to the cytoplasm to be decoded by ribosomes.

3.  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

4. The “code” of the chromosome is the SPECIFIC
ORDER that bases occur.
A T C G T A T G C G G…

5.  http://www.youtube.com/watch?v=8kK2zwjRV0M&feat

6.  The genetic code is a sequence of
nucleotides in the __________ of
eukaryotic cells.
 There are two polymers of nucleic
acids, _____ and ______.

7.  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

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

9.  The bases form the “rungs” on the DNA ladder
by complementary pairing
A == T
C == G
T == A
G == C
A == T
T == A
Sugar-
phosphate
backbone

10.  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

12. How does DNA replicate?

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

15.  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.

17.  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

19.  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