ONS/ONCC Chemotherapy Immunotherapy
Certificate Updated!!
Lesson 1: Foundations to Set the Stage
What is the cell cycle
The cell cycle is the ordered series of processes of DNA replication and mitosis or cell
division
What are the two phases of the cell cycle
interphase and mitotic phase
During interphase:
A typical cell spends most of its life in interphase, it is the metabolic phase where the
cell obtains nutritional requirements and metabolizes them, grows and replicates its
DNA in preparation of mitosis. It has the following three steps:
1: First growth phase (G1 or first gap)
2: Synthesis phase (S phase)
3:Second growth phase ( G2 or second gap)
First Growth Phase (G1 or first gap)
-cells increase in size
,-reproduce RNA
-"quality assurance" test that the cell will be ready to synthesis DNA
-Length of time is variable, can be from hours to days
Synthesis Phase (S phase)
-DNA replicates
-Results in the formation of identical pairs of DNA (chromatids) attached to a
centromere
-lasts 10-20 hours
Second Growth Phase ( G2 or second gap)
-RNA and protein Synthesis
- last 2-10 hours
Mitotic Phase (M phase)
,-Replicated chromosomes are aligned, separated, and move into 2 new, identical
daughter cells
-takes about 30-60 minutes
How many steps in the Mitotic Phase
4 steps in the mitotic phase
- Prophase
- Anaphase
- Metaphase
-Telophase
Cytokenesis ( C phase)
division of cytoplasm and organelles
Major points of cell regulation are entry and exit from
-G1 checkpoint
-S Phase
-G2 checkpoint
-M phase
Restriction Point
-The transition from the resting phase into an actively dividing phase (G0-G1) is a point
where cellular transformation can occur
-During this period, the cells pass through a transition period known as a restriction
point
-Extracellular growth factors provoke reentry into G1 and GF are required to advance
the cells past the restriction point or the point of no return
G0 Phase-resting phase
, -At the conclusion of mitosis the cells can either reenter the G1 phase or enter a resting
phase known as G0
-Most cells in the human body are in G0
-Exceptions to this are those that are out of the cell cycle Resting in G0 phase
-Exceptions to this are those that are metabollically active, such as
-granulocytes
-and the epithelium of the GI tract
Cell Cycling Time
Amount of time from mitosis to mitosis
Check points in the Cell Cycle: Keeping it All Under Control
-The cell cycle is carefully controlled through a series of checkpoints
Variation in duplication or distribution of chromosomes at the time of cell division may
alter genetic information passed on to daughter cells, thus leading to cellular
dysfunction and disease, such as cancer.
DNA integrity and passage through mitosis are checked through checkpoints.
Certificate Updated!!
Lesson 1: Foundations to Set the Stage
What is the cell cycle
The cell cycle is the ordered series of processes of DNA replication and mitosis or cell
division
What are the two phases of the cell cycle
interphase and mitotic phase
During interphase:
A typical cell spends most of its life in interphase, it is the metabolic phase where the
cell obtains nutritional requirements and metabolizes them, grows and replicates its
DNA in preparation of mitosis. It has the following three steps:
1: First growth phase (G1 or first gap)
2: Synthesis phase (S phase)
3:Second growth phase ( G2 or second gap)
First Growth Phase (G1 or first gap)
-cells increase in size
,-reproduce RNA
-"quality assurance" test that the cell will be ready to synthesis DNA
-Length of time is variable, can be from hours to days
Synthesis Phase (S phase)
-DNA replicates
-Results in the formation of identical pairs of DNA (chromatids) attached to a
centromere
-lasts 10-20 hours
Second Growth Phase ( G2 or second gap)
-RNA and protein Synthesis
- last 2-10 hours
Mitotic Phase (M phase)
,-Replicated chromosomes are aligned, separated, and move into 2 new, identical
daughter cells
-takes about 30-60 minutes
How many steps in the Mitotic Phase
4 steps in the mitotic phase
- Prophase
- Anaphase
- Metaphase
-Telophase
Cytokenesis ( C phase)
division of cytoplasm and organelles
Major points of cell regulation are entry and exit from
-G1 checkpoint
-S Phase
-G2 checkpoint
-M phase
Restriction Point
-The transition from the resting phase into an actively dividing phase (G0-G1) is a point
where cellular transformation can occur
-During this period, the cells pass through a transition period known as a restriction
point
-Extracellular growth factors provoke reentry into G1 and GF are required to advance
the cells past the restriction point or the point of no return
G0 Phase-resting phase
, -At the conclusion of mitosis the cells can either reenter the G1 phase or enter a resting
phase known as G0
-Most cells in the human body are in G0
-Exceptions to this are those that are out of the cell cycle Resting in G0 phase
-Exceptions to this are those that are metabollically active, such as
-granulocytes
-and the epithelium of the GI tract
Cell Cycling Time
Amount of time from mitosis to mitosis
Check points in the Cell Cycle: Keeping it All Under Control
-The cell cycle is carefully controlled through a series of checkpoints
Variation in duplication or distribution of chromosomes at the time of cell division may
alter genetic information passed on to daughter cells, thus leading to cellular
dysfunction and disease, such as cancer.
DNA integrity and passage through mitosis are checked through checkpoints.
