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Wednesday, November 10, 2004

DNA Technology Notes

DNA nucleotides are linked through their sugars and phosphates to form the two backbones of a helical, double-stranded molecule. The carbon atoms are numbered "1" through "5". The "5" end terminates in a phosphate group attached to a 5' carbon. The opposite 3' end terminates with a hydroxyl goup bound to 3' carbon of deoxyribose.

I Prokayrotic Chromosomes- consists of circular DNA localized in the nucleoid.
_A) They consist of plasmids, which replicate independently of the chromosome and thus
_B) can replicate in half the time of Eukaryotic Chromosomes.

II Eukaryotic Chromosomes- typically have more than one chromosome in their genome. _A) They are linear (rather than the circular prokaryotic type)
_B) are contained within the nucleus.
_C) The number of chromosomes vary with the species that will code for a product (protein).

III Protein Synthesis is using a part of DNA to encode an RNA in turn will have the nucleotide sequences that can be translated into amino acid sequences and make a protein.

IV The Central Dogma is the process of a protein being made from a gene or genes.

Anatomy of DNA/RNA- here is an excellent website on the anatomy and differences of the nucleic acids. A simulation of "the replication of DNA" is included in a re-enaction concept series.
VisionLearning-DNA and RNA (Flash player is required)
Protein Synthesis and Gene Expression
Genotype is an actual set of gene make-up.
Phenotype is reference to physical characteristics, such as hair color.
Constitutive Enzymes are enzymes in constant need by the organism (75%)
Induced Enzymes are ones that are not produced routinely, but can be turned on (pregnancy)
Repressed Enzymes are ones that are normally synthesized but can be turned off.
Refer to this site for more detailed information.
Mutation- the changing in nucleotide base sequence of a genome is rare. This leads to a protein having a novel property that improves the ability of an organism and its descendents to live.
Point Mutation- one of a few base pairs are affected. (substitutions, deletions, insertioins)
Frameshift Mutation- nucleotides affected after mutation is displaced.(insertions, deletions)
Insertion/Deletion- (worst type)- affects every codon "downstream"
More information on mutation is found at The Microbiology of Mutation

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