Cell Division and Cell Death

Flashcards covering key vocabulary and definitions related to cell division, the cell cycle, and cell death mechanisms (necrosis and apoptosis).

Cell Proliferation

Involves DNA replication, separation into two cells, and cytokinesis to split the original cell into two new cells.

Cell Cycle

A tightly regulated process where cells divide, with varying rates across different cells.

Mitosis (M phase)

The phase of the cell cycle where nuclei divide and cytokinesis occurs to create two daughter cells.

Interphase

Includes G1, S phase (DNA synthesis), and G2 phases, occupying more of the cell cycle than mitosis.

G1 (GAP1) Phase

Cell prepares by increasing in size, maintaining a single copy of chromosomes; length variability impacts cell cycle duration.

S Phase

DNA replication occurs, creating two identical sister chromatids for each chromosome.

G2 Phase

Preparation for mitosis, assembling structures needed for genetic information separation.

G0 Phase

A quiescent phase where cells rest and are no longer actively dividing.

Cyclin Dependent Kinases (CDKs)

Key regulators of the cell cycle; kinases that phosphorylate proteins, changing their activity.

Cyclins

Proteins present cyclically; bind to CDKs, activating them to phosphorylate specific proteins and impact the cell cycle.

RB (Retinoblastoma) Protein

A negative regulator of the cell cycle; when active, it blocks the cell from going from G1 into S phase.

Cell Cycle Checkpoints

Specific triggers cause pausing at these checkpoints, and the cell will then see if it can rectify the problem.

P21 Protein

Production of this is triggered when DNA becomes damaged, and this binds to the CDK and prevents the cyclin from binding.

Oncogenes

Positive regulators of cell division that become overactive, driving unregulated cell division.

Tumor Suppressors

Negative regulators of cell division that become inactive in cancer cells, leading to unregulated cell cycling.

Mitosis

Process of segregating DNA and producing two identical cells, divided into prophase, prometaphase, metaphase, anaphase, and telophase.

Necrosis

Cell death due to damage, resulting in swelling, membrane breakdown, lysis, and an inflammatory response.

Apoptosis

Programmed cell death eliminates unwanted cells through detachment, shrinkage, chromatin condensation, and engulfment by neighboring cells.

Caspases

Proteases that cleave specific targets, found in the cytoplasm and mitochondria, regulating apoptosis.

BCL-2

Acts to control mitochondrial membrane permeability, preventing the release of cytochrome c and inhibiting apoptosis.