AP Biology Unit Review: Cell Communication, Cell Cycle, and Cell Structure

Signal Transduction Pathway

A series of molecular events triggered when a signaling molecule binds to a receptor, leading to a specific cellular response.

Paracrine Signaling

Local signaling where growth factors stimulate nearby cells to grow and divide.

Endocrine Signaling

Long-distance signaling where hormones travel via the bloodstream to distant target cells.

Reception in Signal Transduction

The stage where a signaling molecule (ligand) binds to a receptor.

Protein Kinases

Enzymes that phosphorylate proteins, activating them.

Mitosis

The process of nuclear division in the cell cycle.

G1 Phase

The first gap phase where the cell grows and prepares for DNA replication.

Checkpoints in the Cell Cycle

Regulatory points (G1, G2, M) that ensure the environment and DNA integrity are suitable for division.

Cell Theory

The fundamental concept that all living things are made of cells and that cells come from pre-existing cells.

Prokaryotic Cells

Cells without a nucleus and membrane-bound organelles (e.g., Bacteria and Archaea).

Endocytosis

The process by which a cell engulfs large molecules.

Quorum Sensing

The mechanism by which bacteria release autoinducers to coordinate group behaviors.

Passive Transport

Movement of substances across the membrane without energy, moving down the gradient.

Osmosis

The movement of water from high to low water potential.

Testosterone

A steroid hormone that binds to an intracellular receptor to regulate gene expression.

HeLa Cells

Immortal cell line used in medical research, originally taken from Henrietta Lacks, raising ethical concerns.