Lecture 8

Question 1

progeria

Answer 1

premature aging- prob with nuclear lamina

Question 2

in regard to lamina, what happens during interphase

Answer 2

it disassembles and is phosphorylated

Question 3

what happens with the lamina during telophase?

Answer 3

reassembles

Question 4

Papillary thyroid cancer gives nuclei with:

Answer 4

clear nuclei- orphan annie eye nuclei

Question 5

what are the three components of the nucleolus

Answer 5

1) nucleolar organizer DNA
2) Pars fibrosa- newly transcribed rRNA starting to be complexed with protein
3) pars granulosa- maturing subunits of ribosomes

Question 6

nucleostemin

Answer 6

binds p53 in undifferenciated cells (remember: stem is the beginning and thus undifferentiated)
may play a role in unchecked proliferation cancer cells because nucleostemin binds p53, taking it up and preventing it from doing it’s proliferation checks

Question 7

what happens in mitosis

Answer 7

division of the nucleus

Question 8

what happens in the s phase

Answer 8

duplication of chromosomes

Question 9

in what phases are centrioles replicated

start and finish

Answer 9

starts at g1- ends at g2

Question 10

what do germinal cells possess that allow the to not reach senescence?
what also has this?

Answer 10

telomerase

cancer cells

Question 11

necrosis vs apoptosis

Answer 11

apoptosis is regulated under immune surveillance and eliminates itself on purpose and don’t get an inflammatory response- eliminate via phagocytosis with macrophages or professional phagocytosis cells
vs
necrosis that happens violently with an inflammatory response

Question 12

what flags a cell for apoptosis

Answer 12

phosphotidyl serine is moved from cytoplamic side to extracellular side to signal apoptosis

Question 13

what are the types of apoptosis? which one is triggered when?

Answer 13

intrinsic- when there is cell damage, uses mitochondria

extrinsic- uses caspases and cytochrome C and receptors like FAS which is a death receptor

Question 14

Fas

Answer 14

a death receptor

Question 15

Fas ligand counter attack

Answer 15

done by cancer cells; express FAS and interact with immuno cells and bind with the FAS receptors there and kill them

Question 16

why is the risk for osteoporosis so much higher post menopause?

Answer 16

in osteoblasts we have BAD (that is bad) which is a pro-apoptotic growth factor that promotes apoptosis of osteoblasts (no bone growth).
BUT we can change it to good (BAD-P) via estrogen via phosphorylation.
after menopause, we dont express as much estrogen so we can’t change BAD into BAD-P so you get osteoporosis