C2005/F2401 '09  Lecture #12 -- OUTLINE -- Last update/posting 10/18/09 02:08 PM

I. DNA Replication, Cont. 

    A. Primers & Primase -- biological consequences of inability of DNA polymerase to start new chains

    B. Bidirectional Replication -- bottom of handout 11-3

II. PCR (Polymerase Chain Reaction) -- a practical application of the need for primers (Handout 12-A)

    A. The method --  how prefab primers are used to copy (amplify) specific sections of the DNA

    B. Some uses of PCR

III. The Central Dogma -- How does "DNA Make Protein?"

    A. Overall picture: DNA → RNA → protein.    

    B. Why messenger RNA (mRNA)?

    C. Also need other types of RNA --  transfer RNA (tRNA) & ribosomal RNA (rRNA). Details on tRNA and rRNA next time.

IV. How is RNA made? DNA synthesis (replication) vs RNA synthesis (transcription) -- see table on handout 12B

• Mechanism of chain growth -- basically the same for DNA & RNA synthesis
• Enzymes used & start signals they recognize  -- promoters for RNA synthesis vs origins for DNA synthesis.
• Template used -- one strand (for RNA synthesis) vs two (for DNA synthesis); sense strand vs. transcribed strand

Next time:  Wrap up of IV, if needed, and then: How is  the RNA used to make protein?