Cell Cycle And Mitosis

Front 1

cell cycle

Back 1

orderly sequence of events by which a cell duplicates its contents and divides in two

Front 2

cyclin dependent kinase

Back 2

Cdk

catalytic subunit

present at same quantity throughout cell cycle

Front 3

cyclin

Back 3

regulatory subunit (Cdk inactive in absence of cyclin binding)

rises and falls in concentration at specific points in cell cycle

directs Cdk to appropriate substrates

Front 4

options for cells that complete mitosis

Back 4

1. exit cell cycle and enter G0 (quiesence)

2. continue through G1 phase and enter S phase

Front 5

characteristics of G0 arrest

Back 5

cell has same DNA content as G1 phase cell

cell hasn't past R point

cells not synthesizing proteins for DNA synth.

cell is metabolically active

cell type specific proteins expressed

"doing its job"

Front 6

conditions that result in G0 arrest

Back 6

absence of growth factors

absence of amino acids (nutritional deprivation)

cell-cell contact

Front 7

characteristics of G1 phase

Back 7

prep for entry into S phase!

assemble preRCs (inactive until S)

synthesize rRNA and proteins to support synthetic activity

Restriction point- in late G1 phase

Front 8

Restriction point

Back 8

regulatory point in late G1 phase

after passing R point cell is committed to enter S phase aka "start" or "point of no return"

Front 9

passage through R point regulated by

Back 9

binding of soluble growth factors to receptors

integrin-mediated adhesion to ECM

Rb protein and its phosphorylation state

Front 10

E2F

Back 10

regulates transcription of genes encoding proteins required for DNA synthesis

action is inhibited by Rb binding

Front 11

S phase

Back 11

time when cell carries out complete and accurate replication of cellular genome

replication origins are not activated simultaneously

Front 12

S phase to G2 phase transition

Back 12

cyclin A/cdk2 binds to and phosphorylates E2F complex to make it NOT bind to promoter

turns off transcription of S phase genes

Front 13

G2 phase

Back 13

1. prevent re-initiation of DNA synthesis

2. decatenation (disentangling) of replicated DNA by topoisomerase II

3. synthesis, assembly, and modification of proteins that regulate G2-->M transition

Front 14

what triggers the G2-->M transition

Back 14

Cyclin B and Cdk (MPF)