Nucleic Acids and DNA Replication

A collection of vocabulary flashcards covering key terms and concepts related to nucleic acids and DNA replication.

Nucleic Acid

Biomolecules, including DNA and RNA, that are essential for the genetic information storage and transfer.

Nucleoside

A building block of nucleic acids consisting of a nitrogenous base and a sugar.

Nucleotide

A basic structural unit of nucleic acids, consisting of a nucleoside and a phosphate group.

Phosphodiester Bond

A type of covalent bond that links nucleotides together in nucleic acids, connecting the phosphate group of one nucleotide to the sugar of another.

RNA World Hypothesis

A theory proposing that ribonucleic acid (RNA) was the first self-replicating molecule, serving both as genetic material and catalyst.

Antiparallel

Refers to the opposite orientation of the two strands in the DNA double helix.

Complementary Base Pairing

The hydrogen bonding between specific nitrogenous bases in DNA (A with T and C with G) and RNA (A with U and C with G).

Telomeres

Protective ends of linear chromosomes that prevent the loss of genetic information during replication.

Meselson and Stahl Experiment

An experiment that demonstrated semiconservative replication of DNA by using isotopes of nitrogen to differentiate between old and new DNA strands.

Leading Strand

The continuously synthesized strand of DNA during replication that is synthesized in the 5' to 3' direction.

Lagging Strand

The strand of DNA replicated discontinuously in short fragments (Okazaki fragments) during DNA replication.

Primase

An enzyme that synthesizes a short RNA primer for the initiation of DNA replication.

DNA Polymerase

An enzyme that synthesizes new DNA strands by adding nucleotides to the growing chain.

Ribozymes

RNA molecules that can catalyze chemical reactions, functioning as enzymes.

Hydrogen Bonding

A weak bond between hydrogen and electronegative atoms (like oxygen or nitrogen), critical for base pairing in DNA.

Conservative Replication

Hypothesis suggesting that the parent DNA molecule serves as a template for an entirely new molecule, yielding one old and one new DNA molecule.

Dispersive Replication

Hypothesis suggesting that the parent DNA molecule is broken into pieces and that each new DNA molecule contains both old and new DNA.

DNA Helicase

An enzyme that unwinds the DNA double helix by breaking hydrogen bonds between base pairs.

DNA Ligase

An enzyme that joins separate DNA fragments by forming phosphodiester bonds, sealing nicks in the sugar-phosphate backbone.