Structure and Organization of Nucleic Acids Flashcards Preview

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Flashcards in Structure and Organization of Nucleic Acids Deck (48):
1

categories of noncoding DNA sequences

spacer sequences
introns
genes encoding nonprotein -coding RNAs
repetition DNA sequecnes

2

introns

noncoding sequences within genes

3

what is the most aundant class of noncoding sequences

repeitious DNA

4

satellite DNA

indentical repeasts of short sequences

5

how are satellite DNA repeats arranged

long, tandom arrays

6

organization of satellite DNA is important in what

gives DNA sequence a defined moleculate weight

7

where is most satellite DNA found

centromere and telomere

8

what is the most abundant class of repetitious DNA

interspersed repeats

9

exons

sequences that are translated into proteins

10

characteristics of genes in eukaryotes

discontinuous and consist of exons and introns

11

gene families arise form waht

gene duplication events

12

what are the similiaries between genes within a gene family

simliar nucleotide sequences and encode similiar proteins

13

pseudogene

when you have a duplicate gene that gets mutated adn inactivated

14

what is unique about a duplicate copy of a gene

it's expendable and axxumulates mutations over time

15

chromatine

nuclear DNA that's extensively associated with proteins

16

nucleosome

histone with DNA wrapped around them

17

homologous chromones

materal and paternal versions of same chromsome are similiar but not identifcal

18

how is mitochondrial genome different from nuclear genome

it's circular
it's poresent in mulitiple copies per organelle
high gene density
not extensively associated with proteins

19

what is the principal feature that sets eukaryotes apart from prokaryotes

nucleus

20

heterochromatin

intensely stain, compelxed with proteins, highly condensed and transcriptionally inactive

21

where is heterochromatin found

periphery of nucleus

22

euchromatin

translucent, contains transciriptionally active, decondensed DNA

23

nucleolus

large, intesnly stained area that contains genes encoding ribosomal RNA

24

what are chromosomes attached to

nuclear matrix

25

what are chromomsomal territories serprated by

interchromosomal domains

26

nuclear lamina

meshwork of filaments that astabilize the nuclear envelope on the inner surface

27

nuclear pore function

regulate traffic between nucleus and cytoplasm

28

what are teh 3 main types of large molcules that much be actively and selectively transported between nucleus and cytoplasm

mRNA
proteins
ribosomal subinits

29

what import protein helps with import of molecules into the nucleus

importin

30

what small GTP bindign protein mediates nucleu export

Ran

31

the majority of mRNA molecules are exported from the nucleus via what

ran-independent mechanism

32

what protein associated with the cytoplasmic face of nuclear pore complex and helps provide energy input needed for transport

Dbp5

33

what type of replication is DNA

semi-convservative

34

how are replication origins activated

in clusters

35

replication is _______ from each orgiin

bidirectional

36

how are nucleosomes replicated

existing histones are recycled whilst an equal numver of new histones are syntheized

37

what do you call enzymes that syntheisze DNA

DNA polyermases

38

all DNA polymerases are what

template directed

39

what is requried for DNA replication

primer

40

wha ter primers made from

RNA

41

how are RNA primers degrated

exonuclease

42

polymerases synthesize DNA in what direction

5' -> 3'

43

the newly synthesized DNA straing is _____ to the template strand

antiparallel

44

what are the nucletide donors for DNA synthesis

dATP, dGTP, dCTp, dTTP

45

what is released as each nucletoide is incoroprated

pyrophosphate

46

hydrolysis of pyrophossphate does waht

drices reaction to the right

47

how are origins of replication marked

oriin recognition compelx

48

waht DNA sequence is at telomeres

TTAGGG