11.5 apoptosis

Question 1

apoptosis

Answer 1

controlled cell suicide

• -cellular agents chop up DNA and fragment the organelles
• -cell shrinks and becomes lobed “blebbing”
• -the cell parts are packaged in vesicles and digested by specialized scavenger cells

Question 2

in C. elegant (soil worm) how is apoptosis done

Answer 2

signal activates a cascade of “suicide proteins”

• without a signal, ced-9 keeps ced-4 and ced-3 from activating in the cascade
• with signal, ced-9 inactivates and ced4 and ced3 make proteases and nucleases

Question 3

main proteases in apoptosis

Answer 3

caspases

-in soil worms, the chief caspase was ced3

Question 4

mitochondrial apoptotic proteins

Answer 4

–form molecular pores in the mitochondrial outer membrane causing it to leak and release proteins that promote apoptosis (like cytochrome c)

Question 5

where do apoptosis signals come from

Answer 5

1- neighboring cells
2- if DNA has suffered irreparable damage
3- if excessive misfolding occurs in the ER