Cell Cycle
Consists of sequential phases of events wherein the parent cell divides and replicates DNA materials to produce two daughter cells
For growth
For cell differentiation
For repair and healing of damaged tissues
For replication of genetic materials
For reproduction of species
Cells Undergo Cell Cycle Processes for…
Cell reproduction
Cells Division is also known as
Cell Replacement
Occurs when old cells in the body die and new cells form
Reproduction
A common process among life forms to make a new organism from one or two parent organisms
Sexual Reproduction
Involves two specialized cells, called Gametes, coming from the parents that will result to a unique offspring
Asexual Reproduction
The production of offspring from a single parent without the involvement of gametes
Binary Fission
The cell pinches apart, splits into two, then a new cell wall forms between two daughter cells
Chromosomes
An organized structure where DNA, a double-stranded molecule is tightly coiled
Deoxyribonucleic acid
What does DNA stands for?
Chromatin
Complex set of macromolecules that contain loose DNA, proteins and RNA
Sister Chromatids
identical copies formed by the replication of a chromosome
Chromatid
Refers to each strand of duplicated chromosomes
Kinetochore
Group of proteins located at the centromere that is attached to the long spindle fibers during cell division
Telomeres
Located at the end of the DNA "X" it contain genetic information that do not translate into traitsÂ
Centromere
A region of condensed pinched chromosomes
Interphase
The longest growth period consist of 3 phases: G1, S, G2
Gap 1
Cells increase their size as their organelles double in number
Synthesis
the DNA replicates, doubling of genetic material
Gap 2
Contains a critical checkpoint before transitioning to the next stage
The production of enzymes occurs
Mitosis
Division of nucleus into two genetically identical nuclei containing the same full set of DNA.
Prophase
Chromatin condenses into tightly coiled chromosomes
Nucleolus disappears
Spindle fibers are formed by the organized microtubules
Metaphase
Spindle fibers attached to the kinetochore of the sister chromatids facilitates the movement of the chromosomes towards the middle of the cell
Metaphase Plate
Chromosomes lined up along the plane equidistant from a microtubule region called ____________________
Anaphase
The spindle fibers (centriole) begins to pull the sister chromatids away from each other toward the opposite ends of the cell
Cohesin breaks down
Telophase
The 2 complete sets of identical chromosomes are now positioned at each pole of the cell, nuclear membrane starts to form back again making 2 nucleus and ready for cytokinesis
Cytokinesis
Involves splitting the cytoplasm into two cells and completes the entire stage of cell cycle
Starts with the formation of cleavage furrow or trench that is pulled inward by tiny strands of protein called microfilaments, the membrane begins to pinch roughly in half and close off, forming a separate cell around each nucleusÂ
Regulation of cell cycle
Cells do not divide in situations where nutrients are short in supply
Cell division is energy demanding process
Cells do not divide when there are no instruction to divide
These cells are usually activated by both internal (inside the cell) external (outside the cell) factors
External Factors
Come from outside the cell
Physical signals
cell-to-cell contact
Chemical signals
__________Â released by the cell such as growth factors provide instruction for the other cells to grow
Erythropoietin
__________ stimulates the production of cells that become red blood cells
Contact inhibition
When a cell touches another cell, it stops dividing
Anchorage dependent
Cells only grow if surface is available and stop dividing when detached from the culture dish
Internal Factors
Come from inside the cell include several types of molecules in its cytoplasm
Kinase
An enzyme that transfers a phosphate group from one molecule to the target molecule
Cyclins
Are rapidly destroyed at certain points in the cell cycle to allow cells to progress from G1 to M stage
Kinases that help control cell cycle can be activated by a group of protein called ______
Apoptosis
Cell death or suicide
Interphase
Prophase
Metaphase
Anaphase
Telophase
Cytokinesis
46 chromosomes
How many chromosomes does a human being body cells have?
DNA
It is a double stranded molecule, is tightly coiled in an organized structure called chromosome.
Chromatin
These are responsible for packaging the DNA efficiently into smaller volume so that it fits the nucleus of a cell.
Growth factor
Protein that stimulate cell division, which have the ability to activate specific genes to trigger cell growth.
Interphase
Mitosis
Cytokinesis
Definite stages of cell cycle
Cleavage Furrow
Parts of a Chromosome