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
Mitosis involves ____ (division of the nucleus) and _____ (division of the cytoplasm), resulting in production of 2 identical daughter cells
karyokinesis
cytokinesis
_____ function as microtubule organizing centers and function as the mitotic spindle pole during mitsosis
centrosomes
_____ microtubules radiate from centrosomes and function to separate spindle poles and position them in the cell
astral
____ microtubles extend from each pole and overlap in middle of the cell. They are responsible for pushing poles of cell apart
polar
____ microtubules attach to each kinetochore that forms at the centromere of duplicated chromosomes. These move separated daughter chromatids to each pole
kinetochore
____ is a constriction in the middle of attached sister chromatids where a kinetochore (protein complex) is assembled
centromere
____ is the first phase. In this phase, chromosomes condense from ____. The mitotic spindle begins to form and ____ begin to develop at the centromere region
prophase
chromatin
kinetochores
_____ is the second phase of mitosis. The nuclear envelope breaks down and ____ gain access to chromosomes. ____ migrate to opposite poles of cell and give rise to spindle fibers and astral rays of mitotic spindle. ___ complete attachment and attach to spindle microtubules
prometaphase
microtubules
centrioles
kinetochores
In _____, the third phase of mitosis, kinetochore microtubules align chromatids at the ____ plate
metaphase
metaphase
In _____, chromatids separate and daughter chromosomes move to opposite poles of the cell. _____ _____ begins to form between cells
anaphase
cleavage furrow
In ______, kinetochore microtubules disappear, the nuclear envelope reforms, and the cleavage furrow between cells deepens.
Telophase
____form a family of proteolytic enzymes that are activated in apoptosis and drive the apoptotic cascade
caspases
The Bcl-2 family of proteins regulate _____ membrane potential and can be both pro-apoptotic and anti-apoptotic.
mitochondrial
In _____, the mitochondrial membrane potential collapses and causes release of mitochondrial proteins like ______ and smac/DIABLO
apoptosis
cytochrome C
In apoptotic cell, the nuclear chromatin will marginate and condense. The cell will _____ and the cell membrane will _____
shrink
bleb
_____ is phase 6 of mitosis. In this phase, There are 2 recognizable daughter cells, each with a complete nuclear envelope
cytokinesis
The ____ phase follows the S phase and extends to mitosis. This phase sees cells resting and preparing to divide.
G2
The cell cycle is permanently interrupted in differentiated cells that do not divide, such as cardiac muscle cells and _____
neurons
Cells in _ phase will take up tritated thymidine (ie BRDU) which can be counted to measure cell prolifereration
S
A hallmark of _____ is condensing chromatin
prophase
The nuclear envelope fully breaks down in this stage of mitosis: _____
prometaphase
The nuclear envelope is completely reformed by ______ in mitosis
cytokinesis
Cytochrome C and SMAC/Diablo lead to _____ activation
caspase
If Dr. Turek could be any cell, he would be a _______
macrophage.
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