Chapter 16- Molecular Basis of Inheritance

Unwinds parental double helix at replication forks

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

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

Synthesizes an RNA primer at 5 prime end of leading strand and of each Okazaki fragment of lagging strand.

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

Removes RNA nucleotides of primer from 5 prime end and replaces them with DNA nucleotides

an enzyme that catalyzes the lengthening of telomeres in eukaryotic germ cells, thus restoring their original length and compensating for the shortening that occurs during DNA replication.

joins 3 prime end of DNA that replaces primer to rest of leading strand and joins Okazaki fragments of lagging strand

the initial RNA transcript, including those coding for RNA that is not translated into a protein. Consists of pre-mRNA, to later be modified

only 4 nucleotide bases to specify 20 amino acids, how many bases correspond to an amino acid?

mRNA produced by transcription is immediately translated without additional processing

nucleus provides a separate compartment for transciption, so pre-mRNA is processed before leaving nucleus as RNA

triplets of nucleotide bases, smallest units of uniform length that can code for all the amino acids (4^3=64). Each specifies an amino acid to add to the growing polypeptide chain

flow of information from gene to protein, genetic instructions for a populpeptide chain written in the DNA as a series of nonoverlapping 3-nucleotide words

template strand