DNA Structure, Base Pairing, and X-ray Crystallography in Molecular Biology

What are the four deoxyribonucleotides mentioned?

dAMP, dGMP, dTMP, dCMP

What is the structure of a ribonucleotide?

A ribonucleotide has a phosphate group on the 5' carbon and an open hydroxyl group on the 3' carbon.

What is the significance of deoxyadenosine triphosphate (dATP)?

dATP is a building block for DNA synthesis.

What is the main difference between DNA and RNA nucleotides?

DNA contains deoxyribose, while RNA contains ribose.

Who were the key figures in discovering the structure of DNA?

James Watson, Francis Crick, Maurice Wilkins, and Rosalind Franklin.

What did Watson and Crick contribute to DNA research?

They built a model of DNA based on known structures of nucleotides and X-ray diffraction data.

What are Chargaff's rules regarding base composition?

Adenine equals Thymine (A = T) and Guanine equals Cytosine (G = C).

What does the X-ray diffraction pattern of DNA suggest?

It suggests a helical structure with a periodicity of 3.4 angstroms.

What is the significance of Photo 51?

It provided critical evidence for the helical structure of DNA.

What type of bonds hold the two strands of DNA together?

Hydrogen bonds between complementary bases.

What is the orientation of the sugar-phosphate backbone in DNA?

The sugar-phosphate backbones run antiparallel to each other.

How many hydrogen bonds form between Cytosine and Guanine?

Three hydrogen bonds.

How many hydrogen bonds form between Thymine and Adenine?

Two hydrogen bonds.

What is the structure of a polynucleotide chain?

It has a 5' phosphate end and a 3' hydroxyl end.

What is H-DNA?

H-DNA is a three-stranded structure that can form when DNA unwinds.

What is the primary form of DNA found in cells?

B form DNA.

What is the role of internal base pairing in RNA?

It contributes to the secondary structures like hairpins and stems.

What is the distance for one full turn of the DNA helix?

Approximately 10 base pairs per full turn.

What is the diameter of the DNA helix?

The diameter is about 2 nanometers.

What are the three forms of DNA mentioned?

A form, B form, and Z form.

What is the significance of the major and minor grooves in DNA?

They provide binding sites for proteins and other molecules.

What is the impact of base pairing rules on DNA replication?

They allow for the prediction of complementary DNA sequences.

What is the relationship between purines and pyrimidines in DNA?

A purine pairs with a pyrimidine in the DNA structure.

Who is Rosalind Franklin and what was her contribution?

She was a scientist whose X-ray diffraction images were crucial in understanding DNA's structure.

What does the term 'antiparallel' refer to in DNA structure?

It refers to the opposite orientation of the two DNA strands.

What is the significance of the 1962 Nobel Prize in Medicine?

It was awarded to Watson, Crick, and Wilkins for their work on DNA structure.