1. Molecular Biology I. Introduction A. History
1. J. Meischer (1868) found a consistent band rich in acid-phosphates from cellular samples.
2. F. Griffith (1928) showed that protein was not the inherited molecule.

2. 3. E. Chagraff (1942) showed that in DNA T=A and G=C.
4. S. Luria, M. Delbrook, A. Hershey, and M. Chase (1952) found that DNA was the inherited molecule.
Figure 11.4

3. 6. J. Watson & F. Crick (1953) built a model of DNA.
5. R. Franklin (1952) found that DNA had a uniform diameter, helical shape, and repeatable sequences..
6. J. Watson & F. Crick (1953) built a model of DNA.
Figure 11.4

4. II. DNA Replication A. Definition and When? B. Rules
1. Directional: build DNA 5’ to 3’ by reading 3’ to 5’
2. Semi-conservative
Figure 11.5
Figure 11.6

5. C. Process by Enzyme Players
1. DNA Helicase un-winds DNA to form replication bubbles.
2. RNA Primase lays down short RNA base sequence against DNA.
Figure 11.7

6. 3. DNA Polymerase III reads 3’ to 5’ direction and lays down DNA bases in a 5’ to 3’ direction. Leading edge vs. Lagging edge (Okasaki fragments).
4. DNA Polymerase I edits excises RNA sequences and DNA Ligase folds the strands together (new to old).

7. III. Genetic Code A. DNA  RNA  Protein B. Triplet Code Why?
Transcription
Translation
B. Triplet Code
Why?
Figure 11.9

8. C. Specific Codes = Start, Stops, Special, and Redundancy
Figure 11.10

9. IV. Transcription A. Definition & Players B. Process
1. Initiation  transcription factors recognize promoter (called a TATA box) to attach, unwind, and orient RNA polymerase along the DNA strands.
Figure 11.11

10. 2. Elongation  RNA polymerase reads DNA and lays down RNA bases.
Which direction?
3. Termination  initiation factors recognize Terminator (called a CAT box) and release the RNA polymerase
4. Modification of RNA
Which direction?
Figure 11.12

11. V. Translation A. Definition & Players B. Process
1. Initiation  rRNA ribosomal small subunit reads start codon on mRNA, attaches, first tRNA lands to match it’s anti-codon to codon and then the large ribosomal subunit attaches to the small.
Figure 11.14

12. 2. Elongation  matching tRNA’s anti-codon to mRNA’s codons within the ribosome as the ribosome (rRNA) slides along the mRNA. Bind AA from first tRNA to the AA attached to the second tRNA, release the first tRNA, slide ribosome down over the next codon on the mRNA. Continue.
Figure 11.15

13. Codon Chart
Figure 11.10

14. 4. Modification  cutting and folding of new protein.
3. Termination  ribosome reads a stop codon, protein is released from the last tRNA, release last tRNA, and remove ribosome.
4. Modification  cutting and folding of new protein.
Figure 11.16

15. C. Organelles Nucleus & Ribosomes!
1. Intracellular
What organelles are involved in building proteins which are to be used by the cell?
Nucleus & Ribosomes!
2. Extracellular
What organelles are involved in building proteins which are to be put into vacuoles for shipping or retention?
Nucleus, Ribosomes, rER, Golgi, & Vacuoles!