Chapter 13 Molecular Basis of Inheritance Flashcards
James Watson and Francis Crick introduced what?
double-helical model for the structure of deoxyribonucleic acid, or DNA
Hershey and Chase showed that ____ is the genetic material that provides genetic information.
DNA
What are the DNA nitrogenous base pairings?
Adenine and Thymine / Cytosine and Guanine
True or False: In any species the percentages of A and T bases are equal and the percentages of G and C bases are equal
True
What is the semiconservative model of DNA?
when a double helix replicates, each daughter molecule will have one old strand (derived or “conserved” from the parent molecule) and one newly made strand
What is the origin of replication?
Site where replication begins
What is the replication bubble?
“bubble” that forms when DNA is being separated
What is the replication fork?
Region where parental DNA gets unwound
What is Helicase?
enzyme that untwists the double helix at the replication forks
What is a single strand binding protein?
proteins that bind to and stabilize single-stranded DNA
What is topoisomerase?
enzyme that relieves the strain caused by tight twisting ahead of the replication fork by breaking, swiveling, and rejoining DNA strands
Enzymes that synthesize DNA cannot initiate synthesis of a polynucleotide; they can only add nucleotides to an already existing chain base-paired with the template. What is the the initial nucleotide strand used?
short RNA primer (5-10 nucleotides long)
What is primase?
an enzyme that starts an RNA chain with a single RNA nucleotide and adds RNA nucleotides one at a time using the parental DNA as a template
What is DNA polymerase?
Enzymes that catalyze the elongation of new DNA at a replication fork
True/False: Most DNA polymerases require a primer and a DNA template strand
True
