Unit 3 Proteins & Nucleic Acids

Question 1

Explain the evidence of DNA as genetic material

Answer 1

• protein was the genetic material bc it was more complex
• T2 bacteriophage was used bc if simple structure
• cultured 2 versions of the virus
  (Radioactive S and P)
  -bacteria infected –> blender separation –> centrifuge to form pellet –> radioactivity was measured

Question 2

X ray diffraction

Answer 2

1. Cross–> helical
2. angle of cross –> pitch (steepness of angle) of helix
3. d b/w horizontal bars –> d b/w turns of helix (3.4nm)
4. d b/w middle and top –> v distance b/w adjacent bp

Question 3

Y is DNA in prokaryotes said to b naked

Answer 3

Bc they don’t pack the DNA into cromosomas due to the absence of Histone proteins