Cell Bio Ch 18

Question 1

apoptosis- greek for ______

Answer 1

“falling from”

Question 2

morphological changes in apoptotic cells

Answer 2

1. cells shrink and condense
2. cytoskeleton collapses
3. nuclear envelope disassembles
4. cell surface breaks into apoptotic bodies
5. apoptotic bodies are engulfed by neighboring cells or macrophages
6. Mitochondrial membrane becomes permeable, allowing release of proapoptotic proteins

Question 3

apoptosis is_______

Answer 3

programmed cell death

Question 4

programmed cell death eliminates ______

Answer 4

unwanted cells

Question 5

2 major pathways for signaling apoptosis

Answer 5

intrinsic pathway- triggered from within the cell by stress or DNA damage
extrinsic pathway- activated when a pro-apoptotic ligand binds to a proapoptic receptor

Question 6

_________ are intracellular enzymes that trigger cell death.

Answer 6

caspases

Question 7

Caspases are ____ that have a cysteine at the active site and cleave their target proteins at specific _______

Answer 7

proteases

aspartic acids

Question 8

Once activated, caspases clave and activate _____

Answer 8

other procaspases, amplifying proteolytic cascade.

Question 9

procaspases which operate in start of proteolytic cascades are called_____

Answer 9

initiator caspases

Question 10

when activated, initiator caspases cleave and activate _______ which cleaves targes proteins.

Answer 10

executioner caspases

Question 11

________ activate the extrinsic pathway of apoptosis

Answer 11

cell-surface death receptors

Question 12

Death receptors are transmembrane proteins that contain a _______ which is required for receptors to activate apoptosis.

Answer 12

death domain

Question 13

Death receptors belong to the _______ family of receptors

Answer 13

TNF (tumor necrosis factor)

Question 14

FADD

Answer 14

fas-associated death domain

Question 15

DISC

Answer 15

death-inducing signaling complex

Question 16

killer lymphocytes have _______ attached that activate ________ receptors on the cell surface.

Answer 16

Fas ligand

fas death receptors

Question 17

intrinsic pathway of apoptosis depends on

Answer 17

mitochondria and the release of mitochondrial proteins

Question 18

a water soluble component of electron transport chain in mitochondria

Answer 18

cytochrome C

Question 19

when released into cytosol, cytochrome C binds to ______ activating ________

Answer 19

procaspase

adaptor proteins called Apaf1

Question 20

Once active, Apaf1 begins to ______

Answer 20

oligomerize to form a wheel hep tamer called “apoptosome”

Question 21

______ are anti-apoptotic proteins

Answer 21

Bcl2

Question 22

_______ and ______ are pro-apoptotic proteins

Answer 22

BH123 and BH3

Question 23

pro-apoptotic BH123 oligomerization causes

Answer 23

the release of cytochrome C from the mitochondria

Question 24

in the absence of apoptotic signals, anti-apoptotic ______ binds to pro-apoptotic BH123, stopping the release of cytochrome C

Answer 24

Bcl2

Question 25

pro-apoptotic _____ proteins promote apoptosis by inhibiting anti-apoptotic Bcl2 proteins

Answer 25

BCH3

Question 26

inefficient apoptosis leads to disease

Answer 26

autoimmune disease and tumors and cancer

Question 27

autoimmune disease

Answer 27

anti-self lymphocytes are not all killed as they should be in the thymus or spleen

Question 28

cells with badly damaged DNA that don’t undergo apoptosis can accumulate more mutations, and cause

Answer 28

tumors or cancer