ch 14 Flashcards
cell cycle and death
four main stages of the cell cycle
G1 phase
S phase
G2 phase
M phase
restriction point
cell decides to enters dormant state G0
cell cycle check points
cell cycle is paused to ensure cell is good for the next step
where are the DNA damage checkpoints
G1
S
G2
spindle assembly checkpoint
M checkpoint
cyclins
proteins that move cell from one phase to the next
cyclins activate…
cyclin-dependent kinases (CDKs)
cyclin-dependent kinases (CDKs)
proteins that phosphorylate and activate other proteins that control cell division
what do Cyclin E and Cdk2 do
drive transition from G1 to S phase
mitosis
parent cell divides into daughter cells
prophase
DNA condenses tightly into chromosomes
nucleus deteriorates
mitotic spindles start forming
sister chromatids
chromosomes two halves
mitotic spindles
microtubule fibers that pull chromatids apart
what controls most steps of prophase
cyclin B and CDK1
control DNA condensing
nuclear envelope breaking down
mitotic spindles forming
nuclear lamina
holds nucleus together
lamin
proteins that make up the nuclear lamina
intermediate filament
metaphase
metaphase plate
M-phase cell checkpoint occurs
metaphase plate
chromosomes align at center plane of cell
anaphase
sister chromatids begin to separate
pulled to opposite sides of cells
telophase
chromosomes reach opposite sides of cell
spindles disappear
nuclei reform around daughter chromosomes
cytokinesis
cells split apart via contractile ring
contractile ring
made of actin, splits cell in two
why do cells die (2)
necrosis (unintentionally)
apoptosis (intentional)
necrosis
unexpected/unintended cell death
cell ruptures in an uncontrolled manner, disrupts function of nearby cells