2.17 Cell Cycle and Apoptosis Flashcards Preview

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Flashcards in 2.17 Cell Cycle and Apoptosis Deck (78)
1

Confined to a specific part of the body

Local Control

2

Involves multiple organ systems, or the whole body

Systemic Control

3

How do cells reproduce

Cell division of existing cells

4

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

True

5

True or false
Synthesis takes place after mitosis

False
M after S

6

Chromosomes are segregated and packaged into separate nuclei

Mitosis

7

Separation of two nuclei into two genetically identical daughter cells

Cytokinesis

8

Two major processes of M phase

Mitosis
Cytokinesis

9

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

Interphase

10

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

Metaphase

11

Division into two daughter cells is completed

Cytokinesis

12

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

Anaphase

13

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

Prophase

14

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

Telophase

15

Stages of mitosis

Interphase
Prophase
Metaphase
Anaphase
Telophase
Cytokinesis

16

Bipolar array of microtubules that become attached to the sister chromatids

Mitotic spindle

17

Mitosis depends on the machinery of the ___

Mitotic spindle

18

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

Dynein -mediated

19

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

Kinesin-mediated

20

Large protein complex that provides microtubule binding site on the chromosome

Kinetochore

21

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

Congression

22

Holds the sister chromatids together

Cohesin

23

After birth and before the cell gets ready to split

G1

24

Exit for non-proliferating, differentiated cells
Cells remain in a quiescent state

G0

25

Replication

S

26

Getting ready for mitosis

G2

27

Mitosis

M

28

Timing
Rapidly dividing human cells
Mitosis
G1
S
G2

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

29

Timing
Rapidly growing yeast cells

around 90 minutes

30

E. coli doubing time

20 m

31

How is the timing maintained?

Dominoes or clocks as model

32

The next phase is dependent on the previous part

Dominoes

33

Schedule is followed

Clock

34

Clock timer that has feedback points for regulation

Control system

35

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

G1/S checkpoint
Restriction point

36

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

G2/M checkpoint

37

Check for chromosome attachment to spindle fiber

Metaphase to anaphase checkpoint

38

Heart of the control system

Cyclins and Cyclin-dependent Kinases (CDK)

39

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

False
The other way around

40

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

Early G1

41

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

Late G1

42

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

S-phase CDK complex

43

G1 CDK phosphorylates the inhibitor, targeting it for degradation

Near the start of S-phase

44

Marks the onset of S-phase

Release of S-phase CDK

45

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

Mitotic CDK complexes

46

Activation of Mitotic CDK begins at ___

M-phase

47

Targets cohesin regulators for degradation, allowing segragation of sister chromatids

Anaphase promoting complex (APC)

48

Degrades mitotic CDK complexes, resulting in the final mitotic events

APC

49

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

False
Not possible

50

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

Phosphorylation

51

Proteins are controlled via:

Phosphorylation
Degradation

52

Two methods of degradation

Via lysosome
Via ubiquitin-meidated proteasomal degradation

53

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

Ubiquitin

54

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

True

55

Protein degrading machine

APC

56

APC is regulated by __

Phosphorylation

57

Direct anaphase promoter

APC

58

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

Securin

59

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

Cohesin degradation

60

G1-CDK

Cyclin D
CDK4, 6

61

G1/S -CDK

Cyclin E
CDK2

62

S - CDK

Cyclin A
CDK2, 1

63

M - CDK

Cyclin B
CDK 1

64

Signal proliferation

Growth factors

65

Cancer drug which is a proteasome inhibitor

Velcade

66

Active ingredient in Velcade

Bortezomib

67

Programmed cell death

Apoptosis

68

Blebbing of the cell

Apoptosis

69

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

Necrosis

70

Apoptosis is triggered by:

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

71

Failure to pass the cell cycle checkpoints leads to __

Cell cycle arrest

72

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

p53

73

TNF binds to __ (Fas receptor)

Death receptor

74

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

External pathway

75

Involved after death signaling

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

76

Triggers apoptosis

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

77

True or false
Apoptosis is reversible

Depends.
True unless DNA damage is permanent

78

Implications of reversibility when it comes to chemotherapy

Anastasis