Chapter 9: DNA Structure and Replication

Two requirements for genetic material

1. replicate itself

2. provide info for cell to function

scientist who identified "transforming factor" that transmitted infectiousness in bacteria

Frederick Griffith

How did Avery, MacLeod, and McCarty build upon Griffith's work?

proved that the "transforming factor" is DNA

What landmark setup did Hershey and Chase use to confirm DNA is the genetic material?

the "blender" experiments (using viruses and radioactivity).

What did Hershey and Chase prove is NOT the genetic material?

protein

What did Phoebus Levene discover about the chemical proportions of DNA?

has equal proportions of deoxyribose, nitrogenous bases, and phosphates.

Chargaff’s Rule regarding DNA base pairs

amount of A=T and G=C

Which three scientists analyzed DNA structure using X-ray diffraction?

Wilkins, Franklin, Gosling

name of X-ray diffraction photograph taken by Franklin and Gosling

Photo 51 (helical shape)

Who used these collective findings to deduce the 3D double helix model?

Watson and Crick

ribose

A 5-carbon sugar that is part of RNA.

deoxyribose

A 5-carbon sugar that is part of a DNA nucleotide.

nucleotide

The building block of a nucleic acid, consisting of a phosphate group, a nitrogenous base, and a 5-carbon sugar.

Purine

A nucleic acid base with a two-ring structure; adenine and guanine.

Pyrimidine

A nucleic acid base with a single-ring structure; cytosine, thymine, and uracil

Sugar-phosphate backbone

The “rails” of a DNA double helix, consisting of alternating deoxyribose and phosphate group

opposing orientation of 2 polynucleotide DNA molecule chains

antiparallelism

The pairs of DNA bases that form hydrogen bonds

complementary base pairs

type of protein around which DNA coils in a regular pattern

histone

A DNA “bead”; DNA coils around an octet of histones

nucleosome