2.17 Cell Cycle and Apoptosis

Question 1

Confined to a specific part of the body

Answer 1

Local Control

Question 2

Involves multiple organ systems, or the whole body

Answer 2

Systemic Control

Question 3

How do cells reproduce

Answer 3

Cell division of existing cells

Question 4

True or false

DNA replication and cell division must take place in a highly coordinated fashion in eukaryotes

Answer 4

True

Question 5

True or false

Synthesis takes place after mitosis

Answer 5

False

M after S

Question 6

Chromosomes are segregated and packaged into separate nuclei

Answer 6

Mitosis

Question 7

Separation of two nuclei into two genetically identical daughter cells

Answer 7

Cytokinesis

Question 8

Two major processes of M phase

Answer 8

Mitosis

Cytokinesis

Question 9

Nucleolus and nuclear envelope are distinct and the chromosomes are in the form of threadlike chromatin

Answer 9

Interphase

Question 10

Thick, coiled chromosomes, each with two chromatids, are lined up on the metaphase plate

Answer 10

Metaphase

Question 11

Division into two daughter cells is completed

Answer 11

Cytokinesis

Question 12

The chromatids of each chromosome have separated and are moving toward the poles

Answer 12

Anaphase

Question 13

The chromosomes appear condensed, and the nuclear envelope is not apparent

Answer 13

Prophase

Question 14

The chromosomes are at the poles, and are becoming more diffuse. The nuclear envelope is reforming. The cytoplasm may be dividing

Answer 14

Telophase

Question 15

Stages of mitosis

Answer 15

Interphase
Prophase
Metaphase
Anaphase
Telophase
Cytokinesis

Question 16

Bipolar array of microtubules that become attached to the sister chromatids

Answer 16

Mitotic spindle

Question 17

Mitosis depends on the machinery of the ___

Answer 17

Mitotic spindle

Question 18

__ movement towards minus end of microtubules, these minus ends are located towards the centrosome

Answer 18

Dynein -mediated

Question 19

___ movement towards plus end, some microtubule plus ends are attached to the kinetochore

Answer 19

Kinesin-mediated

Question 20

Large protein complex that provides microtubule binding site on the chromosome

Answer 20

Kinetochore

Question 21

Movement of the sister chromatids lining up at metaphase plate and connected to the opposite poles

Answer 21

Congression

Question 22

Holds the sister chromatids together

Answer 22

Cohesin

Question 23

After birth and before the cell gets ready to split

Answer 23

G1

Question 24

Exit for non-proliferating, differentiated cells

Cells remain in a quiescent state

Answer 24

G0

Question 25

Replication

Answer 25

S

Question 26

Getting ready for mitosis

Answer 26

G2

Question 27

Mitosis

Answer 27

M

Question 28

``` Timing Rapidly dividing human cells Mitosis G1 S G2 ```

Answer 28

``` around 24 hours; 0.5 h; 9 h 10 h 4.5 h ```

Question 29

Timing | Rapidly growing yeast cells

Answer 29

around 90 minutes

Question 30

E. coli doubing time

Answer 30

20 m

Question 31

How is the timing maintained?

Answer 31

Dominoes or clocks as model

Question 32

The next phase is dependent on the previous part

Answer 32

Dominoes

Question 33

Schedule is followed

Answer 33

Clock

Question 34

Clock timer that has feedback points for regulation

Answer 34

Control system

Question 35

Checks for cell size, nutrients, growth factors, and DNA damage

Answer 35

G1/S checkpoint | Restriction point

Question 36

Checks if replicated DNA is suitable for cell division - no mutation, appropriate cell size

Answer 36

G2/M checkpoint

Question 37

Check for chromosome attachment to spindle fiber

Answer 37

Metaphase to anaphase checkpoint

Question 38

Heart of the control system

Answer 38

Cyclins and Cyclin-dependent Kinases (CDK)

Question 39

True or false | In control system, cyclins are always present while CDKs are variable

Answer 39

False | The other way around

Question 40

DNA pre-replication complexes are dephosphorylated, and they assemble onto chromosome replication origin

Answer 40

Early G1

Question 41

G1 CDK compelxes are synthesized | These kinases phosphorylate and activate certain transcription factors

Answer 41

Late G1

Question 42

Target of the transcription factors are genes encoding components of the ___ , which is blocked by a specific inhibitors

Answer 42

S-phase CDK complex

Question 43

G1 CDK phosphorylates the inhibitor, targeting it for degradation

Answer 43

Near the start of S-phase

Question 44

Marks the onset of S-phase

Answer 44

Release of S-phase CDK

Question 45

Made during S-phase and G2, but activities are inhibited until DNA synthesis is complete

Answer 45

Mitotic CDK complexes

Question 46

Activation of Mitotic CDK begins at ___

Answer 46

M-phase

Question 47

Targets cohesin regulators for degradation, allowing segragation of sister chromatids

Answer 47

Anaphase promoting complex (APC)

Question 48

Degrades mitotic CDK complexes, resulting in the final mitotic events

Answer 48

APC

Question 49

True or false | Transcription level control is possible after the S phase because DNA is tightly bound as chromosomes

Answer 49

False | Not possible

Question 50

Kinases turn or or off proteins needed after the S phase through ___

Answer 50

Phosphorylation

Question 51

Proteins are controlled via:

Answer 51

Phosphorylation | Degradation

Question 52

Two methods of degradation

Answer 52

Via lysosome | Via ubiquitin-meidated proteasomal degradation

Question 53

only protein that attaches to cohesin because of the presence of enzymes that are specific to both substrates

Answer 53

Ubiquitin

Question 54

True or false | Degradation of the stage-specific proteins ensures one way traffic

Answer 54

True

Question 55

Protein degrading machine

Answer 55

APC

Question 56

APC is regulated by __

Answer 56

Phosphorylation

Question 57

Direct anaphase promoter

Answer 57

APC

Question 58

Protects protein linkages that hold the chromatids, also an inhibitor of separase

Answer 58

Securin

Question 59

When separase is no longer inhibited by securin, it leads to ___

Answer 59

Cohesin degradation

Question 60

G1-CDK

Answer 60

Cyclin D | CDK4, 6

Question 61

G1/S -CDK

Answer 61

Cyclin E | CDK2

Question 62

S - CDK

Answer 62

Cyclin A | CDK2, 1

Question 63

M - CDK

Answer 63

Cyclin B | CDK 1

Question 64

Signal proliferation

Answer 64

Growth factors

Question 65

Cancer drug which is a proteasome inhibitor

Answer 65

Velcade

Question 66

Active ingredient in Velcade

Answer 66

Bortezomib

Question 67

Programmed cell death

Answer 67

Apoptosis

Question 68

Blebbing of the cell

Answer 68

Apoptosis

Question 69

Characterized by extensive tissue damage Cystolic matter spills into the extracellular space through the damaged plasma membrane and this may provoke inflammatory response

Answer 69

Necrosis

Question 70

Apoptosis is triggered by:

Answer 70

Absence of signals from trophic factors Internal conditions in the cell (induced by toxins that enter the cell) External death signals

Question 71

Failure to pass the cell cycle checkpoints leads to __

Answer 71

Cell cycle arrest

Question 72

Gene regulator of the cell cycle | Inhibits the activity of cyclin-CDK complexes upon detection of DNA damage

Answer 72

p53

Question 73

TNF binds to __ (Fas receptor)

Answer 73

Death receptor

Question 74

Binding of TNF to death receptors which activates caspases and leads to appoptosis

Answer 74

External pathway

Question 75

Involved after death signaling

Answer 75

Activation of Caspase 8, 3 | Fomration of apostosome: mitochondrial cytochrome-c, apaf-1 and caspase 9

Question 76

Triggers apoptosis

Answer 76

Plasma membrane (GF withdrawal) Nucleus (irreparable DNA damage) Death receptor signaling ER (unfolded proteins)

Question 77

True or false | Apoptosis is reversible

Answer 77

Depends. | True unless DNA damage is permanent

Question 78

Implications of reversibility when it comes to chemotherapy

Answer 78

Anastasis