bio ex 3 dna structure

Prokaryotes vs eukaryotes structure (ft ploid shi)

• Prokaryotes: one circular chromosome 

  • Plasmid: small (excess) dna located in cell

    • All inside of nucleoid (inner structure)

• Eukaryotes: two (or more) chromosomes

  • Linear chromosomes

    • Stored in nucleus

• Both: Ribosomes—structure that reads dna into rna

  • Creates gene expression

DNA itself structure (deoxygenated, double stranded)

• DNA: Collection of sugar-phosphate backbone onto which nitrogenous bases are bound

  • Deoxyribose – sugar with oxygen attached

    • Dna backbone

  • Nucleic acid – nitrogen base attached to phosphate group

    • Actual genetic code

• Dna double stranded

  • Two sugar backbones each attached to particular subset of nucleic acid

    • Sugar backbones create double helix shape

Nucleotide ft. purines vs pyrimidines, a and G stuff, pruine always to pyrimidine t chagraff why not

• Nucleotide —- 3 requirements:

  • Nitrogenous base attached to

  • Deoxyribose sugar attached to

  • Phosphate group

• Purines: double ringed nucleic acids

  • Larger nitrogenous bases

  • Adenine and Guanine

• Pyrimidines: single ringed nucleic acids

  • Cytosine and Thymine (dna only)

  • Uracil (rna)

• A = T (two binds), G = C (three binds)

  • Purine always attached to pyrimidine

    • Maintain structural shape and rigidity of dna molecule at all times

avery experiment

• 1. Has rna and dna

• 2. Has protein and dna

• 3. Has protein and rna 

• Transformation occurs 1 and 2

  • Conclusion: dna contains genetic material

griffith experiment

Dna from s- strain cells transformed the benign r strain cell into something virulent

hershey & chase experiment

• Gene expression in DNA, not protein

  • Virus dna enters host cell, protein does not