Cyclin, CDKs, Cell Cycle Checkpoints – Lecture 4

Question 1

control of cell cycle:

cell cycle is controlled in part by a class of proteins called ___

Answer 1

cyclins

Question 2

control of cell cycle:

cell cycle is controlled in part by a class of ___ called cyclins

Answer 2

class of proteins

Question 3

control of cell cycle:

___ is controlled in part by a class of proteins called cyclins

Answer 3

cell cycle

Question 4

control of cell cycle:

cyclins (definition)

Answer 4

regulatory proteins that accumulate and degrade in a cell-cycle specific fashion

Question 5

control of cell cycle:

as cell cycle progresses, cyclin protein concentration inside cell ___

Answer 5

increases

Question 6

control of cell cycle:

w/o cyclin proteins, the cell cycle would ___

Answer 6

stop

Question 7

cyclins regulate kinases:

kinases (definition)

Answer 7

protein enzymes that phosphorylate (add a phosphate group to) other molecules

Question 8

cyclins regulate kinases:

phosphatases (definition)

Answer 8

enzymes that de-phosphorylate (remove a phosphate group from) other molecules

Question 9

cyclins regulate kinases:

getting ___ affects the activity of a protein

Answer 9

phosphorylated

Question 10

cyclins regulate kinases:

getting phosphorylated affects the activity of a ___

Answer 10

protein

Question 11

cyclins regulate CDKs:

CDK (what does it stand for?)

Answer 11

cyclin dependent kinases

Question 12

___ regulate CDKs

Answer 12

cyclins

Question 13

cyclins regulate ___

Answer 13

CDKs

Question 14

cyclins regulate CDKs:

___ are kinases that are inactive unless they are attached to a cyclin protein

Answer 14

CDKs

Question 15

cyclins regulate CDKs:

CDKs are ___ that are inactive unless they are attached to a cyclin protein

Answer 15

kinases

Question 16

cyclins regulate CDKs:

CDKs are kinases that are ___ unless they are attached to a cyclin protein

Answer 16

inactive

Question 17

cyclins regulate CDKs:

CDKs are kinases that are inactive unless they are ___ to a cyclin protein

Answer 17

attached

Question 18

cyclins regulate CDKs:

CDKs are kinases that are inactive unless they are attached to a ___

Answer 18

cyclin protein

Question 19

cyclins regulate CDKs:

when ___ are activated by a cyclin, they can then phosphorylate their target proteins

Answer 19

CDKs

Question 20

cyclins regulate CDKs:

when CDKs are ___ by a cyclin, they can then phosphorylate their target proteins

Answer 20

activated

Question 21

cyclins regulate CDKs:

when CDKs are activated by a ___, they can then phosphorylate their target proteins

Answer 21

cyclin

Question 22

cyclins regulate CDKs:

when CDKs are activated by a cyclin, they can then ___ their target proteins

Answer 22

phosphorylate

Question 23

cyclins regulate CDKs:

when CDKs are activated by a cyclin, they can then phosphorylate their ___

Answer 23

target proteins

Question 24

cyclins regulate CDKs:

cyclins activate CDKs –> phosphorylates target proteins:

ultimately, this results in changes w/in cell that are necessary to advance the ___

Answer 24

cell cycle

Question 25

cyclins regulate CDKs:

cyclins activate CDKs –> phosphorylates target proteins:

ultimately, this results in changes w/in ___ that are necessary to advance the cell cycle

Answer 25

cell

Question 26

cyclins regulate CDKs:

cyclins activate CDKs –> phosphorylates target proteins:

ultimately, this results in changes w/in cell that are necessary to ___ the cell cycle

Answer 26

advance

Question 27

overview of cyclins, CDKs, and cell cycle:

Answer 27

cell cycle progresses

cyclin proteins accumulate in cell

cyclins activate CDKs

CDKs phosphorylate target proteins

phosphorylated target proteins advance cell cycle

Question 28

cyclins are needed to proceed thru cell cycle ___

Answer 28

checkpoints

Question 29

cyclins are needed to proceed thru ___ checkpoints

Answer 29

cell cycle

Question 30

___ are needed to proceed thru cell cycle checkpoints

Answer 30

cyclins

Question 31

cyclins are needed to ___ cell cycle checkpoints

Answer 31

proceed thru

Question 32

cell cycle checkpoints (definition)

Answer 32

points during the cell cycle at which the progression of cell cycle can be stopped

Question 33

what is purpose of cell cycle checkpoints?

Answer 33

prevent cell division during:

• improper environmental conditions
• incompletely replicated or damaged DNA
• misaligned chromosomes

Question 34

what happens during cell division during improper environmental conditions:

Answer 34

probably would be lethal

Question 35

what happens during cell division w/ incompletely replicated or damaged DNA:

Answer 35

probably would be lethal, or lead to uncontrolled cell division

Question 36

what happens during cell division w/ misaligned chromosomes:

Answer 36

could also be lethal (unequal division of DNA)

Question 37

cell cycle checkpoints:

there are ___ main cell cycle checkpoints

Answer 37

3

Question 38

cell cycle checkpoints:

what are the 3 main cell cycle checkpoints

Answer 38

1) G1/S transition checkpoint
2) G2/M transition checkpoint
3) spindle checkpoint

Question 39

G1/S transition checkpoint:

Answer 39

AKA start or restriction checkpoint

commitment to divide at all (regulated by cyclin/CDKs)

Question 40

G2/M transition checkpoint:

Answer 40

commitment to proceed into mitosis (regulated by cyclin/CDKs)

Question 41

spindle checkpoint

Answer 41

commitment to segregate the replicated DNA to opposite ends of the cell (anaphase)

regulated by APC (anaphase promoting complex)

Question 42

cell cycle checkpoints:

APC:

Answer 42

anaphase promoting complex

regulates commitment to segregate replicated DNA to opposite ends of cell during anaphase in spindle checkpoint

not a cyclin/CDK complex

Question 43

if cell fails the test at any checkpoint:

Answer 43

cell division is halted for repairs or cell death is induced (apoptosis)

Question 44

apoptosis

Answer 44

cell death

Question 45

cell cycle checkpoints:

G1/S (start or restriction) CP:

Answer 45

regulated by cyclin/CDKs

proper environmental conditions

sufficient nutritional state of cell

sufficient size of cell

Question 46

cell cycle checkpoints:

G2/M (transition) CP:

Answer 46

regulated by cyclin/CDKs

is DNA completely replicated

no DNA damage

sufficient size of cell

Question 47

cell cycle checkpoints:

spindle CP:

Answer 47

regulated by APCs (anaphase promoting complex)

are the chromosomes aligned properly for DNA segregation

Question 48

cancer and cell cycle regulation:

genes that control the cell cycle are the most frequently mutated genes in all forms of ___

Answer 48

cancer

Question 49

cancer and cell cycle regulation:

___ that control the cell cycle are the most frequently mutated genes in all forms of ___

Answer 49

genes

Question 50

cancer and cell cycle regulation:

genes that ___ are the most frequently mutated genes in all forms of cancer

Answer 50

control the cell cycle

Question 51

cancer and cell cycle regulation:

genes that control the cell cycle are the ___ in all forms of cancer

Answer 51

most frequently mutated genes

Question 52

cancer and cell cycle regulation:

Answer 52

cells start the cell cycle when they shouldn’t

cells proceed to mitosis/cytokinesis when they shouldn’t

cells don’t die when they should (evasion of apoptosis)

Question 53

cancer and cell cycle regulation:

cancer cells continue to ___ and become more and more difficult to treat

Answer 53

accumulate mutations

Question 54

cancer and cell cycle regulation:

cancer cells continue to accumulate mutations and become more and more ___

Answer 54

difficult to treat

Question 55

cancer and cell cycle regulation:

___ continue to accumulate mutations and become more and more difficult to treat

Answer 55

cancer cells