Ch. 16 Vocab Flashcards Preview

AP Biology > Ch. 16 Vocab > Flashcards

Flashcards in Ch. 16 Vocab Deck (18):
1

a virus that infects bacteria; aka a phage

bacteriophages

2

the form of native DNA, referring to its two adjacent antiparallel polynucleotide strands wound around an imaginary axis into a spiral shape

double helix

3

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

semiconservative model

4

site where the replication of a DNA molecule begins, consisting of a specific sequence of nucleotides

origins of replication

5

a Y-shaped region on a replicating DNA molecule where the parental strands are being unwound and new strands are growing

replication fork

6

an enzyme that untwists the double helix of DNA at the replication forks, separating the two strands and making them available as template strands

helicases

7

a protein that breaks, swivels, and rejoins DNA strands; helps relieve strain in the double helix ahead of the replication fork during DNA replication

topoisomerase

8

a short stretch of RNA with a free 3' end, bound by complementary base pairing to the template strand, that is elongated with DNA nucleotides during DNA replication

primer

9

an enzyme that catalyzes the elongation of new DNA by the addition of nucleotides to the 3' end of an existing chain

DNA polymerases

10

the new complementary strand synthesized continuously along the template strand toward the replication fork in the mandatory 5'-->3' direction

leading strand

11

a discontinuously synthesized DNA strand that elongates by means of Okazaki fragments, each synthesized in a 5'-->3' direction away from the replication fork

lagging strand

12

a short segment of DNA synthesized away from the replication fork on a template strand during DNA replication, many of which are joined together to make up the lagging strand of newly synthesized DNA

Okazaki fragments

13

a linking enzyme essential for DNA replication; catalyzes the covalent bonding of the 3' end of one DNA fragment to the 5' end of another DNA fragment

DNA ligase

14

an enzyme that cuts DNA or RNA, either removing one or a few bases or hydrolyzing the DNA or RNA completely into its component nucleotides

nuclease

15

the tandemly repetitive DNA at the end of a eukaryotic chromosome's DNA molecule that protects the organism's genes from being eroded during successive rounds of replication

telomeres

16

a dense region of DNA in a prokaryotic cell

nucleoid

17

the complex of DNA and proteins that makes up a eukaryotic chromosome; exists as a mass of very long, thin fibers when the cell isn't dividing

chromatin

18

the conversion of a normal animal cell to a cancerous cell; a change in genotype and phenotype due to the assimilation of external DNA by a cell

transformation