Chapter 16 Flashcards
Bacteriophage
A virus that infects bacteria
DNA replication (DNA synthesis)
The process by which a DNA molecule is copied
Semiconservative model
Type of DNA model which has 1 old strand and 1 new strand
Where does replication begin
Origin of replication
Replication fork
Y-shaped region of replicating DNA where parental strands unwinding and new strands are synthesized
Helicase
An enzyme that untwists DNA at replication forks
Single-strand binding protein
Proteins that bind to unpaired DNA preventing them from coming back together
Topoisomerase
Protein that breaks, swivel, and rejoins DNA strands
Primer
Short polynucleotide with 3’ end, bound to template strand and required to start dna synthesis
Primase
Enzyme that synthesizes primer
Leading strands
The new complementary DNA strand synthesized continuously along the template strand towards the replication fork in 5’ to 3’
Lagging strand strand
A discontinuously synthesized DNA. Strand that elongates by means of okazaki fragments in 5’ to 3’ direction away from rep fork
Okazaki fragments
Short segments of DNA synthesized that are joined to make lagging strand
DNA ligase
Catalyzes linking of 3’ end of one DNA fragment to 5’ end of another DNA fragment
Mismatch repair
Cellular process that uses enzymes to replace incorrectly paired nucleotides
Nuclease
Enzyme that cuts DNA or RNA; either removes bases or hydrolyze them into monomers
Telomeres
repetitive DNA at the end of a eukaryotic chromosome’s DNA protecting DNA from eroding
Telomerase
Enzyme that adds nucleotides to telomeres
Nucleosome
Basic unit of DNA packing
Euchromatin
The less condensed form of eukaryotic chromatin that is available for transcription
Heterochromatin
Eukaryotic chromatin that remains highly compacted during interphase and is generally not transcribed
