Unit 4: Cell Communication and Cell Cycle

These flashcards cover key concepts from Unit 4 on cell communication and the cell cycle.

Cell Communication

Cells communicate by sending and receiving chemical messengers.

Homeostasis

A process that maintains a stable internal environment in an organism.

Quorum Sensing

A communication process in bacteria that coordinates behavior based on population density.

Ligand

A signaling molecule that binds to a receptor to initiate a cellular response.

Receptor Protein

Proteins on or in a cell that bind specific signaling molecules to trigger a response.

Endocrine Signaling

Long-distance signaling involving hormones transported via the circulatory system.

Paracrine Signaling

Short-distance signaling between neighboring cells.

Autocrine Signaling

Signaling where the signaling cell and target cell are the same.

Apoptosis

Programmed cell death that occurs as a safeguard in response to damage.

Negative Feedback

A mechanism that counteracts changes in homeostasis by inhibiting further signal production.

Positive Feedback

A self-amplifying process where a change in a system leads to an even greater change.

Cyclins

Proteins that regulate the cell cycle by activating cyclin-dependent kinases (CDKs).

CDKs

Cyclin-dependent kinases that are activated by binding to cyclins to control progression through the cell cycle.

Cell Cycle Checkpoints

Regulatory points in the cell cycle that ensure the cell is ready to proceed to the next phase.

Mitosis

The process of nuclear division in eukaryotic cells that results in two identical daughter cells.

Cytokinesis

The division of the cytoplasm that follows mitosis, resulting in the formation of two daughter cells.

Binomial Fission

The asexual reproduction process in prokaryotes where one cell divides into two.

DNA Replication Checkpoint

A checkpoint that ensures that DNA is fully copied before entering mitosis.

Spindle Assembly Checkpoint

A checkpoint during metaphase that ensures all chromosomes are properly attached to the spindle before separation.

p53 Protein

A tumor suppressor protein that regulates the cell cycle and prevents the division of damaged cells.

Cancer

A disease characterized by uncontrolled cell division, often due to mutations in cell cycle regulation.