ch 14 Flashcards
(22 cards)
What does it to say that the double strand DNA molecule is anti parallel
The 3’ end of one strand faces the 5’ end of the other strand
Nitrogenous bases in DNA include:
adenine, guanine, cytosine, thymine
Dna ligase:
joins pieces of DNA together to complete the synthesized strand
DNA & RNA are composed of individuals monomers called:
nucleotides
How does telomerase enzyme function
it adds DNA nucleotides to the end of the original DNA strand using its own RNA template
In which types of cells does telomerase remain active
germ cells and adult stem cells
where does the molecule unwind to begin the process of DNA replication
origin of replication
nitrogenous base pairs that make up DNA:
adenine pairs with thymine
what is the specific function of the telomeres
to protect genes on linear chromosomes from getting deleted as cells continue to divide
when does DNA replication occur
S phase
Why is RNA prime requited during the synthesis of new DNA
RNA primate provides 3; OH from which DNA polymerase can begin
RNA primers are removed from the newly synthesized strands by:
exonuclease
synthesis of DNA away from the replication forks is accomplished in small pieces known as
Okazaki fragments
which elements are responsible for coating the DNA near the replication forks to prevent it from rewinding back into a double helix
single strand binding proteins
the new strands of DNA are assembled in which direction during replication
5’ to 3’ direction on both the leading and lagging strands
the enzyme responsible for adding nucleotides to the growing chain replicate DNA during s phase called
DNA polymerase
which protein performs the task of securing the DNA polymerase in place on the leading and lagging strands
sliding clamp
the human haploid genome contains how many functional genes
20,000-25,000 genes
one double stranded molecule of DNA will become
two double stranded molecules, each with one old strand and one new strand
during DNA replication what enzyme moves ahead of helices to prevent supercoiling
topoisomerase
in DNA replication the new strand that is synthesized continuously in a direction toward the replication fork is called
the leading strand
