Introduction To Cell Cycle Flashcards
What are the three phases of the cell cycle?
Interphase, Mitosis, Cytokinesis
What happens in prophase?
Chromatin fibers coil, chromosomes condense
Nucleolus disappears
Duplicated chromosome appears as 2 IDENTICAL sister chromatids joined @ their centromeres
Mitotic spindle forms
Centrosomes start to move to opposite sides of the cell
What is a kinetochore?
protein complex assembled at each centromere, serves as the attachment site for spindle microtubule
What happens during prometaphase?
Kinetochore forms and the cell lengthens
What happens during metaphase?
Centrosomes are at opposite poles of cell
Chromosomes aligned at metaphase plate
What happens during anaphase?
Cohesin proteins cleaved
Each chromatid becomes an independent chromosome
Daughter chromosomes move toward centrosomes
Cell elongates
What are cohesin proteins?
protein complex that holds sister chromatids together
What happens during telophase?
Reformation of nuclei
Nucleoli reappear
Chromosomes decondense
Microtubules are depolymerized
Mitosis is complete
What happens during cytokinesis?
Cleavage furrow->daughter cells
What are the three important checkpoints of the cell cycle?
3 important checkpoints are found in G1, G2, and M phases.
What are kinases?
kinases are enzymes that activate or inactivate other proteins through phosphorylation
What are the regulatory molecules of the cell cycle?
Protein kinases and cyclins
When do kinases become active?
When they are bound to a cyclin
That’s why they are called cyclin dependent kinases (CDKs)
How do cyclins get their name?
Cyclins get their name from its cyclically fluctuating concentration in the cell.
What type of growth factors influence the cell cycle?
Growth factors produced by proto-oncogenes and tumor suppressor genes
