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DNA
Chapter 10
Biology
DNA
– DNA REGULATES ALL CELLULAR
ACTIVITY BY REGULATING PROTEIN
SYNTHESIS.
– DNA IS A SELF-REPLICATING
MOLECULE WHICH GETS PASSED ON
FROM ONE GENERATION TO THE NEXT.
EXPERIMENTS: STRUCTURE &
FUNCTION OF DNA
• FREDERICK GRIFFITH: 1928 – HE DISCOVERED THE PROCESS OF TRANSFORMATION IN BACTERIA.
-OSWALD AVERY: 1944 - HE PROVED THAT
DNA IS THE MOLECULE THAT CAUSES
TRANSFORMATION IN BACTERIA.
-ALFRED HERSHEY & MARTHA CHASE: 1953 – THE
GENETIC MATERIAL IS DNA.
• JAMES WATSON & FRANCIS CRICK:
1953 – THEY DISCOVERED THE
DOUBLE – HELIX WHICH MAKES UP
A DNA MOLECULE. THEY CREATED
A MODEL OF DNA.
GENE
• THIS IS THE NITROGEN BASE
SECTION OF A DNA MOLECULE
THAT CONTROLS PROTEIN
SYNTHESIS.
DNA IS A DIRECTIONAL
MOLECULE FOR EACH
HELIX. – DNA REPLICATES ITSELF IN A 5′ CARBON OF
SUGAR TO 3′ CARBON OF SUGAR
DIRECTION OF EACH HELIX. (sketch)
-EACH HELIX IS ANTIPARALLEL TO THE
OTHER ONE (sketch)
CHROMOSOME FORMATION
• DNA COILS AROUND PROTEIN
MOLECULES CALLED HISTONES.
• BEAD – LIKE NULCEOSOMES FORM.
• CHROMATIN FORMS WHEN
NUCLEOSOMES GATHER INTO 30
NANOMETER DIAMETER FIBERS.
• A CHROMOSOME FORMS WHEN THE
CHROMATIN COILS TOGETHER AND
THICKENS.
POLYMERASE CHAIN
REACTION (PCR)
• A GENE OR PIECE OF DNA CAN BE
COPIED MANY TIMES RAPIDLY.