D1.1 DNA Replication (HL)

Flashcards covering key vocabulary and concepts related to DNA structure, replication, and functions based on the lecture notes.

DNA Replication

The process by which a double-stranded DNA molecule is copied to produce two identical DNA molecules.

Semi-conservative process

A method of DNA replication in which each new DNA molecule consists of one old strand and one new strand.

Hershey-Chase experiment

An experiment that demonstrated DNA is the genetic material, using radiolabeled DNA and proteins.

Chromatography

A method used by Chargaff to separate nucleotide bases for quantification.

Antiparallel strands

Description of the two strands of DNA running in opposite directions (5'→3' and 3'→5').

Purine

A type of nucleotide base that includes adenine (A) and guanine (G) and has a double-ring structure.

Pyrimidine

A type of nucleotide base that includes thymine (T) and cytosine (C) and has a single-ring structure.

Nucleosome

A structural unit of DNA, consisting of a segment of DNA wrapped around a core of histone proteins.

DNA polymerase III

An enzyme that synthesizes a new DNA strand by adding nucleotides in the 5'→3' direction.

Okazaki fragments

Short DNA segments synthesized on the lagging strand during DNA replication.

Proofreading

A function of DNA polymerase III that corrects errors during DNA synthesis by excising incorrectly paired nucleotides.

Hydrogen bonds

The type of bond that holds complementary nucleotide bases together in DNA.

Replication fork

The area where the DNA double helix is unwound and separated during replication.

DNA ligase

An enzyme that joins together Okazaki fragments on the lagging strand to create a continuous DNA strand.

Methylation

A chemical modification that alters the charge of DNA and can affect gene expression.

Euchromatin

Loosely packed form of chromatin that is active in transcription.

Heterochromatin

Tightly packed form of chromatin that is generally inactive in transcription.

Transcription

The process of synthesizing RNA from a DNA template.

Translation

The process of synthesizing proteins based on the mRNA sequence.