Chapter 14 Flashcards Preview

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Flashcards in Chapter 14 Deck (48):
1

a virus that infects bacteria

bacteriophages

2

an infectious agent that contains either DNA or RNA surrounded by a protein coat

virus

3

a purine that base-pairs with either thymine in DNA or uracil in RNA

adenine

4

a purine that base-pairs with cytosine in nucleic acids

guanine

5

a pyrimidine that base-pairs with adenine

thymine

6

a pyrimidine that base-pairs with guanine in nucleic acids

cytosine

7

structure in a polynucleotide chain that is formed when deoxyribose sugar(in DNA) or ribose sugars(in RNA) are linked by phosphate groups in an alternating sugar-phosphate-sugar-phosphate pattern

sugar-phosphate backbone

8

the end of a polynucleotide chain at which a phosphate group is bound to the 5? carbon of a deoxyribose sugar

5' end

9

the end of a poly nucleotide chain at which a hydoxyl group is bonded to the 3' carbon of a deoxyribose sugar

3' end

10

method for deducing the position of atoms in a molecule

X-ray diffraction

11

model of DNA consisting of 2 polynucleotide strands twisted around each other

double-helical model

12

feature of DNA in which the specific purine-pyrimidine base pairs A-T and G-C occur to bridge the 2 sugar-phosphate backbones

complementary base pairing

13

strands of double-stranded DNA that run in opposite directions with the 3' end of one strand opposite the 5' end of the other strand

antiparallel

14

the process of DNA replication in which the 2 parental strands separate and each serves as a template for the synthesis of new progeny double-stranded DNA molecular

semiconservative replication

15

a protein that encircles the DNA and binds to the DNA polymerase to tether the enzyme to the template, thereby making replication more efficient

sliding DNA clamp

16

a specific region at which DNA replication commences. Bacterial chromosomes have single origins of replication whereas eukaryotic chromosomes have multiple origins

origin of replication (ori)

17

an enzyme that catalyzes the unwinding of DNA template strands

DNA helicase

18

region of DNA synthesis where the parental strands separate and 2 new daughter strands elongate

replication fork

19

protein that coats single-stranded segments of DNA, stabilizing the DNA for the replication process

single-stranded binding protein (SSBs)

20

an enzyme that relieves the overtwisting and strain of DNA ahead of replication fork

topoisomerase

21

a short nucleotide chain made of RNA that is laid down as the first series of nucleotides in a new DNA strand, or made of DNA for use in the polymerase chain reaction (PCR)

primer

22

an enzyme that assembles the primer for a new DNA strand during DNA replication

primase

23

replication in which a DNA strand is formed in short lengths that are synthesized in the direction opposite of DNA unwinding

discontinuous replication

24

the short lengths of lagging strand DNA produced by discontinuous replication

Okazaki fragments

25

new DNA strand synthesized during replication in the direction of DNA unwinding

leading strand

26

DNA template strand for the leading strand

leading strand template

27

the new DNA strand synthesized discontinuously during replication in the direction opposite to that of DNA unwinding

lagging strand

28

the large, doublestranded helical molecule that contains the genetic material of all living organisms

deoxyribonucleic acid (DNA)

29

the principal replication polymerase in E. coli that synthesizes the majority of the new DNA

DNA polymerase III

30

in E. coli the replication enzyme that replaces the RNA primer at the start of a new DNA segment with DNA

DNA polymerase I

31

the 2 Y-shaped replication forks joined together at the tops of the Ys after DNA is unwound at an origin of replication

replication bubble

32

an enzyme that adds telomere repeats to chromosome ends

telomerase

33

an error in the assembly of a new nucleotide chain in which bases other than the correct ones pair together

base-pair mismatches

34

mechanism during DNA replication in which DNA polymerase backs up and removes a mispaired nucleotide from a newly synthesized DNA strand and then adds the correct nucleotide to the growing chain

proofreading mechanism

35

mechanism to correct base-pair mismatches that escape proofreading

DNA repair mechanisms

36

repair system that removes mismatched bases from newly synthesized DNA strands

mismatch repair

37

a histone and nonhistone protein associated with DNA in a eukaryotic nuclear chromosome

chromosomal protein

38

any assemblage of eukaryotic nuclear DNA molecules and their associated proteins

chromatin

39

a small positively charged(basic) protein that is complexed with DNA in the chromosomes of eukaryotes

histones

40

the basic structural unit of chromatin in eukaryotes consisting of DNA wrapped around a histone core

nucleosome

41

an 8-protein particle formed by the combination of 2 molecules each of H2A, H2B, H3, and H4 around which DNA winds for almost 2 turns

nucleosome core particle

42

a short segment of DNA extending between 1 nucleosome and the next in a eukaryotic chromosome

linker

43

most fundamental level of chromatin packing of a eukaryotic chromosome in which DNA winds for almost 2 turns around an 8-protein nucleosome and linker DNA extends between adjacent nucleosomes. the result is a beads-on-a-string type of structure with a 10-nm diameter

10 nm chromatin fiber

44

level of chromatin packing of a eukaryotic chromosome in which histone H1 binds to the 10-nm chromatin fiber causing it to package into a coiled structure about 30 nm in diameter and with about 6 nucleosomes per solenoid

30-nm chromatin fiber

45

all the proteins associated with DNA in a eukaryotic chromosome that are not histones

nonhistone proteins

46

DNA molecule in bacteria in which hereditary information is encoded

bacterial chromosome

47

the central region of a prokaryotic cell with no boundary membrane separating it from the cytoplasm, where DNA replication and RNA transcription occur

nucleoid

48

A DNA molecule in the cytoplasm of certain prokaryotes, which often contain genes with functions that supplement those in the nucleoid and which can replicate independently of the nucleoid DNA and be passed along during cell division

plasmids