Chapter 8A DNA The chemical Nature of the Gene

Chargaff's rules

Observation by a biochemist in the 1950s which stated that the amount of guanine always equals the amount of cytosine and the amount of adenine in DNA always equals the amount of thymine.

Griffith Experiment

Scientists injected a mouse with harmless strain of Streptococcus pneumoniae (Strain R), mouse lived, injected strain S, mouse died, injected heat-killed S, mouse lived, injected live R and heat killed S, mouse died. Proposed that the R strain transformed

phosphodiester bonds

Bonds that hold the sugars and phosphates together to form the sugar-phosphate backbone between 3' OH of one nucleotide and the 5' of another nucleotide

hydrogen bonds

Chemical bonds that join the A-T and C-G base pairs in DNA and the A-U and C-G pairs in RNA.

purines

Adenine and Guanine are both ____.

pyrimidine

Cytosine, Thymine, and Uracil are both ____.

Avery Experiment

DNA is the transforming principle: treated different tubes of bacteria with RNAse (inhibits RNA production) and DNAse (inhibits DNA function) and observed their effects on replication. the tubes with RNAse did not have any effect on replication, meaning t

Hershey-Chase Experiment

(1952) showed DNA was hereditary material in bacterial viruses, or bacteriophages (protein with DNA); infected bacteria with one of two different labeled bacteriophages ( labeled 32-P DNA and a protein marker ( 35-S); DNA found inside cell and protein fou

DNA methylation

The addition of methyl groups to certain bases in DNA, is associated with reduced transcription in some species, DNA methylation can also cause long-term inactivation of genes in cellular differentiation

nitrogenous base

A nitrogen-containing purine or pyrimidine that, along with a pentose sugar and a phosphate, is one of the three parts of a nucleotide