Where is the information to build the body stored?

What is the most important molecule in the biological world?

DNA

Why is DNA so important? stores genetic information can copy the genetic information stable (maintains accurate genetic info.)

The Size of DNA... If the DNA of one cell is stretched out, it makes a 7 ft. long string There are about 100 trillion cells in the human body If you connected all the DNA together, it would be long enough that it would take light over 10 hours to travel its length (ruptured bacteria) This is a whole lot of information

When was DNA discovered to be the genetic material? Not too long ago!!!

How was DNA discovered to be the genetic material? Griffith’s experiments 1928 Avery, Macleod, and McCarty 1944 Hershey and Chase 1952

Dead S BACTERIA +live R BACTERIA Dead S BACTERIA + heat ? Dead S BACTERIA +live R BACTERIA ?

Dead S BACTERIA +live R BACTERIA + protease + protease Dead S BACTERIA +live R BACTERIA + RNAse + RNAse + DNAse Dead S BACTERIA +live R BACTERIA + DNAse

Bacteriophage

? ?

Where is DNA located?

What is the structure of DNA?

James Watson and Francis Crick Elucidated the structure of DNA 1953 Awarded Nobel Prize in 1962

Rosalind Franklin took x-ray diffraction photos of DNA

The building block of DNA

Chargaff’s Rule amount of A always = T amount of G always = C

Base Pairing

A G T C

How is DNA like a spiral staircase?

Structure of DNA Double helix* two coiled strands of nucleotides running antiparallel to each other (in opposite directions ) *helix – shape of a twisted coil that can fit into a cylinder

How is DNA like a ladder?

DNA – deoxyribonucleic acid – a “twisted ladder “ sides of ladder – sugar and phosphate groups steps of ladder – pairs of nitrogenous bases

Single DNA Strand Base Pairing Double DNA Strand Formation of a chromosome Double Helix

Formation of a chromosome

When does a cell make a copy of its DNA? Before it divides

How does DNA copy itself? How does DNA store genetic information?

DNA Replication animation http://www.youtube.com/watch?v=hfZ8o9D1tus&feature=related http://highered.mcgraw-hill.com/olc/dl/120076/bio23.swf http://www.youtube.com/watch?v=4jtmOZaIvS0&feature=related Simple one below http://www.lewport.wnyric.org/JWANAMAKER/animations/DNA%20Replication%20-%20long%20.html http://www.ncc.gmu.edu/dna/repanim.htm

DNA Replication A G GC CTG T C CG GAC A G GC CTG T C CG GAC A G GC CTG

C G C T T A T T A A A T G G C T T A A A T G G C

What is the DNA sequence on the other strand of DNA? G T C T C A G What is the DNA sequence on the other strand of DNA?

If DNA is too big to leave the nucleus, then how does it instruct the formation of proteins? messenger RNA

Transcription

Transcription the copying of the genetic message from a strand of DNA into a molecule of mRNA (messenger RNA)

* Remember RNA has U instead of T Transcribe the following DNA sequence into a mRNA* sequence: T A C G T A A C G C G C * Remember RNA has U instead of T A U G C A U U G C G C G

What are the differences between DNA and RNA?

Differences between DNA and RNA contains ribose sugar instead of deoxyribose RNA contains uracil (U) instead of thymine (T) RNA is single-stranded