Lecture 9 - The Eukaryotic Cell Cycle & Interphase Flashcards
Define the Cell Cycle
An ordered sequence of events that leads to DNA Replication
What are the 4 Phases of the Eukaryotic Cell Cycle
- M Phase
- G1 Phase
- S Phase
- G2 Phase
What is the Cell Cycle Control System?
Internal control to ensure the proper progression of the cell cycle
What are Cdks?
Cyclin-dependent protein kinases
What happens during the G1 Phase?
- Metabolic Activity
- Cell Growth
- General Repair
The cell grows in mass to prepare the cell for division
What happens during DNA Replication?
each of the 46 chromosomes form identical duplicated DNA molecules
What happens during S phase?
DNA is replicated
What are Centrosomes?
a cellular structure that controls the location, number and orientation of the microtubules
What happens during the G2 Phase?
- Rapid cell growth
- Protein synthesis (accumulation of enzymes)
prepares for mitosis
What are the 6 stages of the M Phase?
- Prophase
- Prometaphase
- Metaphase
- Anaphase
- Telophase
- Cytokinesis
What happens when there is too much or little Apoptosis?
- Too much = cell loss and degeneration
- Too little = Formation of tumours
What is Apoptosis?
A form of programmed cell death induced by external and internal stimuli
What happens during stage 1 of M Phase?
Prophase - chromatin is condensed into visible chromosomes
What happens during stage 2 of M Phase?
Prometaphase
- Nuclear envelope and lamina break down
- Chromosomes attach to spindle microtubules
What happens during stage 3 of M Phase?
Metaphase
- Chromosomes are aligned at spindle equator (midway)
- M checkpoint controls the alignment and attachment of the chromosomes
