Epithelium: Cell Nucleus

Question 1

Cell Nucleus is composed of..

Answer 1

nucleolus chromatin nuclear envelope

Question 2

The Nuclear Envelope has

Answer 2

Inner membrane Outer membrane

Question 3

The inner membrane of the Nuclear Envelope is associated with

Answer 3

Nuclear lamina chromatin ribonucleoproteins

Question 4

The outer membrane of the nuclear envelope is associated with

Answer 4

continuous with membrane of ER ribosomes

Question 5

Nuclear Pore Complex has what type of structure?

Answer 5

Tripartate Structure (octogonal rings)

Question 6

The Nuclear Pore Complex is embedded in ..

Answer 6

the Nuclear envelope

Question 7

The Nuclear Pore complex has what type of proteins

Answer 7

Phe-gly nucleoporins (they control the channels)

Question 8

How do Phe-gly nucleoporins control the channels?

Answer 8

they are the docking sites for nuclear transport factor cargo proteins

Question 9

NLS

Answer 9

Nuclear localization signal pro-lys-lys-lys-arg-lys-val

Question 10

X chromosome inactivation

Answer 10

random can be maternal or paternal in every FEMALE SOMATIC CELL (both x chromosomes in oocytes remain active)

Question 11

X Chromosome inactivation can be seen in …

Answer 11

Barr Bodies Drumsticks of Neutrophil

Question 12

How many times is DNA wrapped around histone octomer in chromatin?

Answer 12

1.65 times

Question 13

What is the linker histone?

Answer 13

H1

Question 14

what is the basic structural unit of chromatin

Answer 14

nucleosome

Question 15

What is the histone octomer composed of ?

Answer 15

H2A, H2B, H3,H4

Question 16

During what phase is chromatin uncondensed?

Answer 16

Interphase (g1,s,g2( Euchromatin

Question 17

what is transcriptionally active chromatin?

Answer 17

Euchromatin

Question 18

Euchromatin

Answer 18

transcriptionally active 10%total chromatin site of synthesis of nonribosomal RNA (mRNA & tRNA) precursors

Question 19

Heterochromatin

Answer 19

condensed transcriptionally inactive 90% of total chromatin

Question 20

Nucleoplasmic Transport What changes Ran-GTP to Ran-GDP? where?

Answer 20

Ran-GAP in cytoplasm

Question 21

What changes Ran-GDP to Ran-GTP

Answer 21

RCC1 In nucleus

Question 22

What does Ran-GBP do?

Answer 22

Ran-gtp binding protein disassociates (NES protein) from Ran-GTP in cytoplasm

Question 23

what do importins bind to?

Answer 23

alpha importin binds to (NLS Protein) beta importin binds to Ran-GDP

Question 24

What is a nuclear exportin?

Answer 24

Crm1

Question 25

Identify from left to right

Answer 25

dense fibrillar component Granular component fibrillar center

Question 26

Nucleostemin Fibrillarin Nucleolin are found in...

Answer 26

Nucleolus

Question 27

Nuclelous is the site of..

Answer 27

sytnethesis of rRNA site of assembly of ribosomal subunits

Question 28

Nucleolus is the product of

Answer 28

chromosome and the nucleolar organizing region (NOR)

Question 29

The nucleolus has three main compartments

Answer 29

Fibrillar Center Dense fibrillar Components Granular Component

Question 30

Fibrillar Center

Answer 30

RNA Pol I signal regonition particle chromatin with repeats of rRNA

Question 31

Dense Fibrillar Center

Answer 31

Fibrillarin Nucleolin ribonucleic prtoeins for rna modification where nascent rRNA is present and undergoing processing (pre-RNA processing) surrounds fibrillar centers

Question 32

Granular Component

Answer 32

Nucleostemin site of assembly of pre ribosomal subjunits (18S (small) 28S (large)) 75% of nuclear mass

Question 33

Nucleolus

Answer 33

diassociates during mitotis (mitotic prophase) reappears at beginning of G1 more than one per nucleus sometimes

Question 34

Nucleolin

Answer 34

forms a coples with RPA which is required for intiation of DNA Synthesis

Question 35

Fibrillarin & Nucleolin

Answer 35

required for pre-RNA processing (dense fibrillar component)

Question 36

Nucleolin & Nucleostemin

Answer 36

AKA shuttling proteins (relocalize from nucleolus to nucleoplasm) in resp to cell stree tnry into S phase (DNA synthesis) can be blocked by shuttling proteins shuttling proteins bidning and inactivate p53 ( protector of DNA damage)

Question 37

Nucleostemin

Answer 37

unrelated to ribosomal biogensis granular componenet

Question 38

rRNA synthesis occurs in what direction

Answer 38

5' to 3'

Question 39

rRNA genes are seen

Answer 39

as repeating units on chromatin separated by nontranscribed spacers the entire rRNA gene is covered by 100 RNA Pol I molecules

Question 40

RNA pol I makes

Answer 40

fibrils that represent rRNA Precursor (45S)

Question 41

45S

Answer 41

rRNA precursor orientated perpendicular to the chromatin axis detached from chromatin axis and cleaves into 28S 18S 5.8S rRNAS

Question 42

What is the large ribosomal subunit? What precursors create the large ribosomal subunit?

Answer 42

60S 28S+5.8S+ 5S( from OUTSIDE of nucleolus)+ 45 proteins

Question 43

What is the small ribosomal subunit? what creates the small ribosomal subunit?

Answer 43

40S 18S+30 proteins

Question 44

The mRNA precursor is transcribed by

Answer 44

RNA Pol II

Question 45

the tRNA precursor is transcribed by

Answer 45

RNA pol III

Question 46

Feulgen Reaction

Answer 46

Specific for DNA hydrolysis with HCL forms aldehyde groups on deoxyribose (DNA sugar) but no ribose (RNA sugar) add Schiff reagents stains DNA with chromatin purple

Question 47

Effect of Felgen reaction on nucleus and nucleolus

Answer 47

nucleus \_stained purple (DNA) nucleolus \_unaffected (RNA)

Question 48

Autoradiography

Answer 48

H^3 Thymine -DNA H^3Uridine -RNA works on living cells

Question 49

PAS RXN

Answer 49

glycogen in cytoplasm stains pruple nucleus remains unstained

Question 50

Basophillia

Answer 50

Toludine Blue (basic dye) binds to negative phospahge group on DNA & RNA All stain blue DNA-chromatin RNA-nucleolus ribosomes (ER) if pretreat with RNAase only identify DNA containing sites if pretreat with DNAase only identify RNA containing sites

Question 51

Acidophillia

Answer 51

Eosin (dye) stains basic proteins

Question 52

Are basic proteins acidophillic or basophillic

Answer 52

Acidophilic (affinity for acid dyes)