Cell death

Question 1

Three fundamental processes that determine the organ and body size

Answer 1

1. Cell growth
2. Cell division
3. Cell survival

Question 2

secreted proteins, proteins bound to the surface of cells, or components of the extracellular matrix

Answer 2

Extacellular signaling molecules

Question 3

stimulate cell division; G1/S-Cdk activity

Answer 3

Mitogens

Question 4

stimulate cell growth; synthesis of proteins and other macromolecules

Answer 4

Growth factors

Question 5

promote cell survival; suppressing apoptosis

Answer 5

Survival factors

Question 6

rate of proliferation depends on the availability of nutrients

Answer 6

Unicellular organisms

Question 7

divide only when the organism needs more cells

Answer 7

Multicellular organism

Question 8

• first mitogen identified
• observation that fibroblasts in a culture dish proliferate when provided with serum not when provided with plasma

Answer 8

Platelet-derived growth factor (PDGF)

Question 9

acts not only on epidermal cells but also on many other cell types, including both epithelial and nonepithelial cells

Answer 9

Epidermal growth factor (EGF)

Question 10

only induces the proliferation of red blood cell precursors

Answer 10

erythropoietin

Question 11

inhibitory extracellular signal proteins; inhibit proliferation

Answer 11

transforming growth factor-β (TGFβ)

Question 12

neurons and skeletal muscles; cell-cycle control system is completely dismantled

Answer 12

terminally differentiated G0 State

Question 13

bind to specific DNA sequences in the promoters of a wide variety of genes that encode proteins required for S-phase entry

Answer 13

E2F proteins

Question 14

which acts as ubiquitin ligase that targets p53 for destruction

Answer 14

Mdm2

Question 15

programmed cell death; “falling off”

Answer 15

Apoptosis

Question 16

cells that die in response to an acute insult

Answer 16

Cell necrosis

Question 17

a form of programmed cell death that is triggered by a specific regulatory signal from other cells

Answer 17

Necroptosis

Question 18

have a cysteine at their active site and cleave their target proteins at specific aspartic acids

Answer 18

Caspases

Question 19

begin the apoptotic process; apoptotic signal → assembly of large protein complexes → dimers →protease activation

Answer 19

Initiator caspases

Question 20

inactive dimers; cleaved by an initiator caspase at a site in the protease domain → rearranged to active form → amplifying proteolytic cascade → kill the cell

Answer 20

Executioner caspases

Question 21

causes the irreversible breakdown of the nuclear lamina

Answer 21

Lamins

Question 22

self-amplifying and irreversible
- is responsible for all the events of apoptosis

Answer 22

Caspase cascade

Question 23

transmembrane proteins; extracellular ligand-binding domain, a single transmembrane domain, and an intracellular death domain

Answer 23

Death receptors

Question 24

help prevent the inappropriate activation of the extrinsic pathway of apoptosis

Answer 24

Inhibitory proteins - FLIP

Question 25

depends on the release into the cytosol of
mitochondrial proteins

Answer 25

Intrinsic or mitochondrial pathway

Question 26

major class of intracellular regulators of the intrinsic pathway

Answer 26

Bcl2 family

Question 27

to promote apoptosis mainly by inhibiting anti apoptotic Bcl2 family proteins

Answer 27

BH3-only proteins

Question 28

line of defense against inappropriate caspase activation is provided by caspase inhibitor proteins

Answer 28

Inhibitors of apoptosis (IAPs)

Question 29

located exclusively in the inner leaflet of the lipid bilayer, but it flips to the outer leaflet in apoptotic cells

Answer 29

Phosphatidylserine

Question 30

cells die by necrosis as a result of ischemia

Answer 30

Heart attacks or strokes

Question 31

chromosome translocation causes excessive production of the Bcl2 protein; B cell lymphoma

Answer 31

Bcl2 gene