AP Bio Unit 4 Review Flashcards

Flashcards for reviewing Unit 4 of AP Biology, covering cell communication, feedback, cell division, and cell cycle regulation.

A basic feature of life, where cells communicate with one another.

Cell Communication

Communication between adjacent cells through junctions, allowing molecules to pass between them.

Direct Cell Communication

A signaling molecule that binds with receptors to initiate a cellular response.

Ligand

A ligand that travels a long distance through the bloodstream from a gland to a target cell.

Hormone

Signaling molecules for short-distance cell-to-cell communication.

Local Regulators

Cell communication in bacteria, where signaling molecules activate genes when a certain intensity is exceeded.

Quorum Sensing

A polysaccharide matrix produced by bacteria that can lead to plaque formation.

Biofilm

The phase of cell signaling where a ligand binds to a receptor molecule.

Reception

The phase of cell signaling where the initial message is changed into another kind of message, often involving amplification.

Transduction

The phase of cell signaling that involves a cellular response, such as activating enzymes or genes.

Response

A molecule produced during transduction that relays the message to the cytoplasm or nucleus.

Second Messenger

Steroid hormones, like estrogen or testosterone, can diffuse through the phospholipid bilayer and bind with a cytoplasmic receptor.

Nonpolar Hormone

Also known as adrenaline, a polar water-soluble hormone released by the adrenal glands during the fight or flight response.

Epinephrine

A membrane-embedded protein that oscillates between inactive and active states, involved in cell signaling.

G Protein

A membrane-embedded enzyme that converts ATP into cyclic AMP (cAMP), a second messenger.

Adenylyl Cyclase

A second messenger in G protein-coupled receptor systems, activates a chain of relay molecules.

Cyclic AMP (cAMP)

A chain of kinases that are activated by phosphorylation, leading to signal amplification.

Phosphorylation Cascade

The terminal enzyme in the epinephrine signaling pathway that converts glycogen into glucose.

Glycogen Phosphorylase

The tendency of a living system to maintain its internal conditions at a relatively constant optimal level.

Homeostasis

A feedback mechanism where the output of a system decreases the system's output, promoting homeostasis.

Negative Feedback

A feedback mechanism where the output of a system increases the system's activity and output, accelerating a process.

Positive Feedback

A hormone released by the pancreas in response to high blood glucose levels, promotes glucose absorption.

Insulin

A hormone released by the pancreas in response to low blood glucose levels, induces the liver to convert glycogen into glucose.

Glucagon

Programmed cell death, a highly regulated process involving the mitochondria and nucleus.

Apoptosis

Moments when the cell checks its internal conditions and decides whether to progress to the next phase of the cell cycle.

Cell Cycle Checkpoints