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Flashcards in 6-1 (8.11.16) Deck (92):
1

chromatin consists of

DNA
histone
non-histone

2

nucleosome is composed of (NOT the def of complex of histones)

nucleosome core particle (NCP) and DNA

3

Ribosomes

"" often occur on the ONM

4

1 stains lightly: its genes are actively transcribing

2 stains darkly: its genes are transcriptionally inactive.

1 Euchromatin

2 Heterochromatin

5

nuclear pore contain "" channels

what goes thru them

aqueous

ions and small molecules

6

large proteins enter via active transport and require what

localization signal

7

lamins are "" filament

intermediate

8

function of nucleolus

makes ribosome subunits

9

cell phase eq

G1 + S + G2 + M (mitosis + cytokinesis)

10

division results in "" (adj) cells

BUT

genetically identical

daughter cells have dif forms

11

condensation purpose

prevent chromosomes from tangling together in mitosis

12

chromosomes are maximally condensed at ""

metaphase

13

disengagement - when does that occur

describe it

G1

centrioles move apart within centrosome

14

a new centriole is called

PRO centriole

15

cells at what phase are used for KARYOTYPE analysis

why

metaphase

chromosomes are maximally condensed

16

what serves as MT organizing center

centrosomes

17

purpose of astor MT

anchor poles to cell periphery

18

daughter chromatids are held together at centromere VIA what protein

CO-HESIN

19

define mitosis

mother -> 2 cells (genetically identical to m)

20

four steps of mitosis

prophase
metaphases
ana
telo

21

cytokinesis begins when

ana or telo

22

purpose of astor microtubules

anchor and pull

23

"" drives telophase

Dephosphorylation

read: D causes nucleus to reassemble
D causes spindle MT to disappear
D causes chromosomes to decondense

24

contractile ring forms where

then what forms

last step of contractile ring

bt membranes at anaphase

cleavage furrow

daughter cells break apart

25

the contraction caused by "" and "" causes cleavage furrow to form

actin
myosin

26

apoptosis def

programmed cell death

27

read: apoptosis AVOIDS inflammation

what causes i then

-

necrosis

28

do prokaryotes have actin, MT, and IMF

NO

29

prokaryotic version of cilia

flagella

30

read: P DNA lacks histones

-

31

dif bt chromatid and chromosome

when chromatids separate, they become chromosome

32

central dogma is

DNA -> transcription -> RNA -> translation -> protein

33

types of RNA (5)

rRNA
mRNA
tRNA
snRNA (small nuclear)
RNAi (miRNA, siRNA)

34

tRNA role

transfer amino acid onto polypeptide chain

35

RNAi role

snRNA role

miRNA - translation inhibit
siRNA - mRNA degrade

RNA splicing (introns, exons) AND telomere maintenance

36

80% of all cellular RNA is this type of RNA

smallest RNA

15% of all cellular RNA is this

rRNA

tRNA

tRNA

37

at least 1 tRNA for # AA

20

38

in eukaryotes, what is a weird thing about mRNA

why

translated mRNA is NOT exact copy of DNA

bc post transcriptional changes

39

three main steps of RNA synthesis in PROKARYOTES

#1. initiation
#2. elongation
#3. termination

40

P RNA synthesis
Initiation steps

-RNA polymerase holoenzyme binds to promoter region

41

what's interesting about promoter region

it is NOT transcribed

42

How does RNA polymerase RECOGNIZE promoter region

in RP, holoenzyme contains a sigma factor

43

within the promoter region are what

(for PROKARYOTES)

ex (2)

highly conserved consensus sequences

ex:
PRIB-NOW box (10 nucleotides before coding region)
35 hexamer

44

P RNA synthesis
Elongation steps

read: once RNA transcription begins, sigma factor dissociates

45

what's key dif bt RNA and DNA polymerase

RNA P = no proofreading ab

46

P RNA synthesis
Termination steps

dep

could be RHO dependent or independent

dep
-RHO factor follows RNA P; RHO factor (helicase protein) recognizes rut sequence (termination signal)

47

Rho-indep termination

newly made RNA has a sequence that allows for creation of hairpin structure

RNA sequence at 3' end is rich in U's, which bind weakly to A's on DNA

new RNA separates from DNA

48

why does U bind to A's

A has two H bonds

49

palindrome def

ABC = BCA

50

the hairpin loop formed in R-IND termination results bc

palindrome

51

euk gene expression is regulated by what (dif from P)

PROMOTER
plus
chromatin
enhancer
inhibitor

52

read: also euk RNA is dif bc it is modified after transcription

-

53

euk transcription initiation - name the 3 dif consensus sequences found in promoters

consensus sequence (in order, closest to farthest)
-TATA/Hogness box
---similar to Pribnow box
-GC box
-CAAT box
---much more farther upstream than TATA

54

the EUK consensus sequences are called what

why

cis acting DNA elements

on the same strand of DNA that is being transcribed

55

where is enhancer

purpose

region of DNA up/down stream of promoter

transcription factors bind to enhancer AND it stabilizes initiation complex

56

enhancer is cis acting

while "" is trans acting

enhancer binding transcription factor

read: trans means from dif gene

57

euk have 3 types of "" polymerases

RNA

58

clinical: "" found in poisonous mushrooms INHIBITS what

alpha A-MAN-I-TIN

RNA polymerase

59

euk transcription
steps of gene expression

#1. chromatin structure regulates gene expression

60

what cannot be transcribed vs what can

why

CANNOT: hetero-chromatin
tightly wound

CAN: euchromatin
loosely wound

61

what kind of DNA Is generally not transcribed

methylated DNA

62

what relaxes chromatin structure to allow for more gene transcription

acetylation of histones

63

euk mRNA undergoes modifications...what are they

5' capping
poly A tail
removal of introns

64

define intron

mRNA that doesn't code for protein

65

what combination permits the start of translation

5'cap

66

define spliceosome

splices mRNA to remove introns AND joins exons together to yield mRNA

67

what accounts for 15% of all genetic diseases

mutation at splice sites

68

read: alternative splicing is a way of diversifying the protein encoding capacity of limited # of genes

-

69

give ex of alternative splicing

-just give key fact

key: TRO-PO-NIN

read: BUT alternative splicing of its gene sequence results in dif isotypes
look for UP level of cardiac specific troponins if suspect heart damage

70

what proteins are involved in transport of fats

two forms

why truncated

Apo-lipo-proteins

A B100
-liver
-untruncated

A B48
-small intestine
-truncated

RNA editing made an error; get early stop codon

71

"" form is the relevant form in mammalian physio

L form

72

what are the two forms of AA

L and D forms

73

what's special about GLYSINE

it is symmetric, therefore does NOT exist in L and D forms

74

formation of peptide bond results in a loss of charged state of stuff

-

75

proline disrupts "" structures

more specific

secondary

interrupts alpha-helices

76

what AA forms disulfide bonds

cysteine

77

"" "" and "" can accept phosphate groups

why

Serine, threonine and tyrosine

OH

78

phosphorylated enzyme = spot opens up and substrate can bind

-

79

define glycosylation

describe the two types

addition of oligosaccharide to protein

#1 Serine or Threonine = 0 glycosylation

#2 asparagine = N glycosylation

80

glycoproteins identity (typical, 2)

secreted (hormones)
receptors

81

beta and alpha chain in insulin are held together by what

disulfide bonds

82

alpha helix and beta sheet
-(1/2) structure

secondary

83

describe secondary and tertiary structure

2: folds into a repeating pattern bc of H bond interactions

3: 3-D folding bc of side chain interactions
(read: ex is disulfide bonds)

84

when does quaternary structure arise

proteins have MULTIPLE polypeptide chains

read: don't occur when protein has just ONE polypeptide chain

85

what protein aids in protein folding

describe their type

why called this

chaperone

heat shock

chaperone synthesis UP when subjected to higher temp

86

clinical application of denatured protein (relate to mad cow disease)

-another name for disease

C-Jacob Disease

prion that is a misfolded version of a normal prion -> ab becomes template -> ab ACCUMULATE -> loss function of neurons

87

HH equation predicts what

AA's side chain charge

88

3 classes of proteins

fibrous
globular
membrane

89

charge of side chains is determined by what

pK

90

what is the only AA with a NH in a ring?

pro-line

91

name two post translational modification

-protein phosphorylation
-glycosylation

92

protein misfolding 2nd example (other than mad cow disease)

AMY...
Alzheimer's disease