Lecture 7 cell cycle Flashcards
The cell cycle consists of two major periods: ____ and ____
interphase
mitosis
The cell cycle is temporarily suspended in non-dividing resting cells which are in the _____ state
G zero
_____ is the longer phase, and the period in which the cell doubles in size and DNA content. It is divided into 3 phases: ___, ___, ___
interphase
G1, S, G2
The ___ is after mitosis, and is where cell growth and protein synthesis occur, restoring daughter cells to normal volume and size
G1
There is a restriction point between G1 and the ____ phase. Cells that fail to reach the restriction point become resting cells and enter the ____ phase
S
G0
DNA replication and protein synthesis occur during ____ phase. Chromosomes become duplicated
S
There are 2 major checkpoints in the cell cycle that are controlled by ____ and ____-dependent _____
cyclins
cyclin dependent kinases
The 2 checkpoints occur between ___ and ____ phase and between ____ and ____.
G1, S
G2, mitosis
____ kinase initiates S phase, while _ phase promoting factor initiates _____
Start
M, mitosis
The 2 primary ways of controlling the cell cycle are regulation of genes that _____ _____ _____ and regulation of ____ ____ that stimulate cell growth.
suppress cell proliferation
growth factors
Normal Rb protein prevents _____. If one copy of Rb is mutated, growth is ____ _____. If both Rb proteins are mutated, ____ occurs
mitosis.
still suppressed
cancer
____ is the DNA repair gene that exhibits frequent mutations in brain and breast cancers.
p53
p53 acts prior to DNA replication by detecting ____ ______ and delaying entry into S phase until _____ is repaired
DNA damage
Damage
Defects in ____ contribute to cancer by allowing defective cells to replicate
p53
Growth factors including ___, ____, and ____ can affect genest that activate the cell-cycle control system. Overexpression of these can lead to uncontrolled proliferation
myc, fos, jun