The Genetic Code and Replication Flashcards

Vocabulary flashcards based on lecture notes about the genetic code and replication.

Virulence

The ability of a virus or a bacterium to cause damage to its host.

Bacteriophages

Viruses that specifically infect bacteria; consist mostly of proteins and DNA.

Nucleotide

A single subunit of DNA, comprised of a sugar, a base, and a phosphate group.

Deoxyribonucleic acid (DNA)

A polymer that contains genetic information made of four different types of subunits called nucleotides.

Phosphodiester bonds

Covalent linkages between adjacent nucleotides in DNA. The phosphate on the 5′ carbon on the sugar ring of an incoming nucleotide is linked to the hydroxyl group on the 3′ carbon of the sugar of the last nucleotide in the growing polymer.

Antiparallel

Describes the opposing orientations of the two strands of double-stranded DNA.

Complementary base pairing

Formation of hydrogen bonds between specific bases (A:T and G:C) on antiparallel DNA strands.

Semiconservative DNA replication

Each strand of a double-stranded DNA molecule is used as a template for synthesis of a complementary antiparallel DNA strand.

Replication fork

During DNA replication, a Y-shaped area where the top of the Y consists of two unwound DNA strands that are both used as templates for semiconservative DNA replication.

RNA primer

During DNA replication, a short stretch of RNA synthesized by primase enzyme that initiates (primes) DNA synthesis.

Leading strand

During DNA replication, the leading strand is synthesized continuously in the 5′-to-3′ direction toward the unwinding replication fork.

Lagging strand

During DNA replication, the lagging strand has a polarity opposite to that of the leading strand, and so it must be synthesized discontinuously as small Okazaki fragments that are ultimately joined into a continuous strand.

DNA polymerase

An enzyme complex that polymerizes DNA in the 5′-to-3′ direction by extending a primer bound to a DNA template.

DNA ligase

During DNA replication, the enzyme that stitches Okazaki fragments together by forming phosphodiester bonds between adjacent nucleotides.