DNA Structure and Replication

Flashcards covering key vocabulary and concepts related to the structure and replication of DNA.

Polynucleotide strands

Two connected strands of nucleotides that form the structure of DNA.

Nucleotide

The monomer of DNA, consisting of a sugar, phosphate group, and nitrogenous base.

Antiparallel strands

Two strands of DNA that run in opposite directions.

Deoxyribose

The sugar component of DNA nucleotides.

Nitrogenous bases

The building blocks of DNA, including adenine (A), thymine (T), cytosine (C), and guanine (G).

Purines

Nitrogenous bases that consist of two rings; includes adenine and guanine.

Pyrimidines

Nitrogenous bases that consist of a single ring; includes thymine and cytosine.

Hydrogen bonds

Weak bonds that hold nitrogenous base pairs together in DNA, with A pairing with T via 2 bonds and G pairing with C via 3 bonds.

Nucleosome

A unit of DNA consisting of a segment wrapped around a core of proteins, forming the structure of chromatin.

Chromatin

The organized and compacted form of DNA and histone proteins.

Chromosome

A long piece of DNA that contains many genes, present in both prokaryotes and eukaryotes.

Gene

A section of DNA that encodes for a protein.

Alleles

Different forms of the same gene that vary in sequence.

Genome

The complete set of DNA within an organism, including all its genes.

Replication fork

The area where the DNA is being unwound and replicated.

DNA polymerase

An enzyme that synthesizes new strands of DNA by adding nucleotides in the 5’ to 3’ direction.

Okazaki fragments

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

Telomeres

Repetitive nucleotide sequences at the ends of chromosomes that protect them from deterioration.

Mismatch repair

A DNA repair mechanism that corrects mispaired bases in replicated DNA.