DNA Structure and Replication

Vocabulary flashcards about DNA structure, replication, and related experiments.

Nuclein

Acid substance with nitrogen and phosphorus found in the nuclei of white blood cells.

Transformation

Conversion of one bacterial type into another, as demonstrated by Griffith.

Avery, MacLeod, and McCarty Experiment

Demonstrated that DNA is the transforming principle by using DNase to prevent transformation.

Hershey-Chase Experiment

Confirmed that DNA, not protein, is the genetic material using bacteriophages and radioactive isotopes.

Ribose

The 5-carbon sugar found in RNA.

Deoxyribose

The 5-carbon sugar found in DNA.

Chargaff's Rules

A = T and C = G, indicating equal proportions of these bases in DNA.

X-ray diffraction

Technique used by Rosalind Franklin and Maurice Wilkins to deduce the structure of DNA.

Photo 51

X-ray diffraction image of the B-form of DNA obtained by Rosalind Franklin.

Double Helix

The three-dimensional structure of DNA, elucidated by Watson and Crick based on previous research.

Gene

A section of a DNA molecule that specifies the sequence of amino acids in a protein.

Nucleotide

The building block of DNA, composed of a deoxyribose sugar, a phosphate group, and a nitrogenous base.

Purines

Adenine (A) and Guanine (G); nitrogenous bases with a double-ring structure.

Pyrimidines

Cytosine (C) and Thymine (T); nitrogenous bases with a single-ring structure.

Phosphodiester bond

The bond that forms between the deoxyribose sugars and phosphates in a DNA strand, creating the sugar-phosphate backbone.

Antiparallelism

The opposing orientation (head-to-toe) of the two polynucleotide chains in a DNA double helix.

Complementary Base Pairing

Specific pairing of purines and pyrimidines via hydrogen bonds (A with T, and C with G).

Histones

Proteins around which DNA coils to form nucleosomes.

Nucleosome

The bead-like structure formed by DNA coiled around histones.

Chromatin

The substance of chromosomes, composed of DNA and proteins.

CTCF

An "anchor" protein that brings together parts of the DNA sequence within the same long DNA molecule to form the overall 'loop-ome' structure.

Semiconservative Replication

The mechanism of DNA replication in which each new DNA double helix conserves half of the original.

Replication Fork

A site where DNA is locally opened, and replication occurs.

Helicase

An enzyme that unwinds the parental double helix during DNA replication.

Primase

An enzyme that adds a short primer to the template strand during DNA replication.

DNA Polymerase

An enzyme that binds nucleotides to form new DNA strands.

Ligase

An enzyme that joins Okazaki fragments and seals other nicks in the sugar-phosphate backbone.

Okazaki Fragments

Short DNA fragments synthesized discontinuously on the lagging strand during DNA replication.

Polymerase Chain Reaction (PCR)

A DNA amplification technique that uses DNA polymerase to rapidly replicate a specific DNA sequence in a test tube.

Sanger Sequencing

A method to deduce a DNA sequence by aligning pieces that differ from each other by the end base, facilitating individual gene sequencing and accuracy checks.

Next-generation sequencing

Massively-parallel sequencing approach that immobilizes DNA pieces on different types of materials, to read and overlap millions of pieces at once, speeding up DNA sequencing.