AP Biology chapter 16 Key terms Flashcards

16: The molecular basis of inheritance

526274578	bacteriophage	A virus that infects bacteria; also called a phage. See phage.
526274579	DNA ligase	A linking enzyme essential for DNA replication; catalyzes the covalent bonding of the 39 end of a new DNA fragment to the 59 end of a growing chain.
526274580	DNA polymerase	An enzyme that catalyzes the elongation of new DNA at a replication fork by the addition of nucleotides to the existing chain.
526274581	double helix	The form of native DNA, referring to its two adjacent polynucleotide strands wound into a spiral shape.
526274582	helicase	An enzyme that untwists the double helix of DNA at the replication forks.
526274583	lagging strand	A discontinuously synthesized DNA strand that elongates in a direction away from the replication fork.
526274584	leading strand	The new continuous complementary DNA strand synthesized along the template strand in the mandatory 5' 3' direction.
526274585	mismatch repair	The cellular process that uses special enzymes to fix incorrectly paired nucleotides.
526274586	nuclease	A team of enzymes that hydrolyze DNA and RNA into their component nucleotides.
526274587	nucleotide excision repair	The process of removing and then correctly replacing a damaged segment of DNA using the undamaged strand as a guide.
526274588	origins of replication	Sites where the replication of a DNA molecule begins.
526274589	phage	A virus that infects bacteria; also called a bacteriophage.
526274590	primase	An enzyme that joins RNA nucleotides to make the primer.
526274591	primer	An already existing RNA chain bound to template DNA to which DNA nucleotides are added during DNA synthesis.
526274592	replication fork	A Y-shaped region on a replicating DNA molecule where new strands are growing.
526274593	semiconservative model	Type of DNA replication in which the replicated double helix consists of one old strand, derived from the old molecule, and one newly made strand.
526274594	single-strand binding protein	During DNA replication, molecules that line up along the unpaired DNA strands, holding them apart while the DNA strands serve as templates for the synthesis of complimentary strands of DNA.
526274595	telomerase	An enzyme that catalyzes the lengthening of telomeres. The enzyme includes a molecule of RNA that serves as a template for new telomere segments.
526274596	telomere	The protective structure at each end of a eukaryotic chromosome. Specifically, the tandemly repetitive DNA at the end of the chromosome's DNA molecule. See also repetitive DNA.
526274597	transformation	(1) The conversion of a normal animal cell to a cancerous cell. (2) A change in genotype and phenotype due to the assimilation of external DNA by a cell.