Biol 103: Introductory Biology I - Lecture 12: DNA Structure and Replication

Flashcards covering key concepts related to DNA structure, replication, and repair from the lecture notes.

DNA

Deoxyribonucleic acid, the hereditary material in all living organisms.

Replicaton Fork

The Y-shaped region where the DNA double helix is separated into two single strands to allow replication.

Semiconservative Model

The process of DNA replication where each daughter DNA molecule consists of one parental and one new strand.

Avery's Experiments

Experiments by Oswald Avery in the 1940s that identified DNA as the transforming principle.

Leading Strand

The DNA strand that is synthesized continuously in the same direction as the replication fork.

Lagging Strand

The DNA strand that is synthesized discontinuously in short segments called Okazaki fragments.

DNA Polymerase III

An enzyme responsible for synthesizing new DNA strands by adding nucleotides.

Okazaki Fragments

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

DNA Repair

Mechanisms by which a cell identifies and corrects damage to the DNA molecules.

Telomeres

Repeated nucleotide sequences at the ends of chromosomes that protect the chromosome from deterioration.

Telomerase

An enzyme that adds repetitive nucleotide sequences to the ends of telomeres, extends the lifespan of cells.

Base-pair Mismatch Repair

A DNA repair system that corrects mismatches of base pairs after DNA replication.

DNA Ligase

An enzyme that joins Okazaki fragments by sealing nicks in the sugar-phosphate backbone.

Bacterial Transformation

The genetic alteration of a bacterial cell resulting from the direct uptake and incorporation of exogenous genetic material.

Nuclease

An enzyme that cleaves the chains of nucleotides in nucleic acids into smaller units.