DNA Replication

Double stranded, completentary base pairng

Mutations

Nucleotide-pair substitutions

Silent Mutation

A nucleotide-pair substitution that has no observable effect on the phenotype

Missense Mutation

A nucleotide-pair substitution that results in a codon that codes for a different aminp acid

Nonsense Mutation

a mutation that changes an amino acid codon to one of the three stop codons, resulting in a shorter and usually nonfunctional protein

Frame-shift Mutation

Insertion

a mutation involving the addition of one or more nucleotide pairs to a gene

Deletion

a mutational loss of one or more nucleotide pairs from a gene

Transcription

The synthesis of RNA using a DNA template

Replication Bubble

Origin(s) of Replication

Site where the replication of a DNA molecule begins, consisting of a specific sequence of nucleotides

Replication Fork

A Y-shaped region on a replicating DNA molecule where the parental strands are being unwound and new strands are being synthesized

Leading Strand

The new complementary DNA strand synthesized continuously along the template stand toward the replication fork in the mandatory 5' -> 3' direction

Lagging Strand

Okazaki Fragments

Short segment of DNA synthesized away from the replication fork on a template strand during DNA replication. many such segments are joined together to make up the lagging strand of newly synthesized DNA

A discontinuously synthesized DNA strand that elongates by means of Okazaki Fragments, each synthesized in a 5' -> 3' direction away from the replication fork

Proteins used in Replication

Helicase

Unwinds parental double helix at replication forks

Single Strand Binding Protein

Binds to and stabilizes single-stranded DNA until it can be used as a template

Topoisomerase

Relieves "overwinding" strain ahead of replication forks by breaking, swiveling and rejoining DNA strands

Primase

Synthesizes an RNA primer at 5' end of leading stand and of each Okazaki fragment of lagging strand

DNA Pol 3

Using parental DNA as a template, synthesizes new DNA strand by covalently adding nucleotides to the 3' end of a pre-existing DNA strand or RNA primer

DNA Pol 1

Removes RNA necleotides of primer from 5' end and replaces them with DNA necleotides

DNA Ligase

Joins 3' end of DNA that replaces primer to rest of leading strand and joins Okazki fragments of lagging strand

Translation

The synthesis of a polypeptide using the genetic information encoded in an mRNA molecule. There is a change of "language" from nucleotides to amino acids

RNA Processing

Modification of RNA primary transcripts, including splicing out of introns, joining of exons, and alteration of the 5' and 3' ends

Semiconservative Replication

DNA replication consits of one old strand, derived from the parental molecule, and one newly made strand