DNA and Protein Synthesis
A. Nucleic Acids and Protein Synthesis
- All functions of a cell are directed from some central form of information.
- This "biological program" is called the Genetic Code. It is where as the way cell store information regarding its structure and function.
B. History
- For years the source of heredity was unknown. this was resoled after numerous studies and experimental research by the following researchers:
He was studying effects of 2 strains of an infectious bacteria, the "smooth" strain was found to cause pneumonia and death in mice. the rough strain did not. He conducted the following experiment:
Source: http://www.ibri.org/Books/Pun_Evolution/Chapter2/fig2-41.jpg |
- The last condition was unusual, as he predicted that the mouse should live.
- Concluded that some unknown substance was transforming the rough strain into the smooth one.
- Tried to determine the nature of this transforming agent. E.g. was it protein or DNA?
- Degraded chromosomes with enzymes which destroyed proteins or DNA.
- Samples with proteins destroyed would still cause transformation in bacteria indicating genetic material was DNA.
- One virus was tagged with 32P on its DNA.
- The other was tagged 35S on its protein coat.
- Researchers found the radioactive P in the bacteria, indicating it is DNA, not protein being injected into bacteria.
4. Watson and Crick
- The constituents of DNA had long been known. Structure of DNA, however was not.
- In 1953, Watson and Crick published findings based on X-ray analysis and other data that DNA was in the form of a "Double-Helix".
- Their findings show us the basic structure of DNA which is as well as we know now.
Source: http://www.g2conline.info/content/c16/16427/16427_watsoncrickatcambridge.jpg |
1. DNA Structure and Function
- DNA Structure and Function
- DNA Replication
2. Protein Synthesis
- Genetic Code
- Transcription
- Translation