Unit 2: Cell Structure, Function, and Homeostasis Study Guide

A set of vocabulary flashcards covering key concepts from the Unit 2 study guide, including homeostasis, feedback loops, levels of biological organization, and cell membrane transport.

Homeostasis

The process which maintains a stable internal environment inside our body, cells, and so on, keeping internal conditions within a safe optimal range to allow cells to function properly.

Stimulus

A change in the internal or external environment.

Receptor

A sensor or cell that is able to detect the stimulus that is occurring and send the information to a control center, such as the brain.

Effector

An organ, gland, or muscle that takes action to a response from a control center.

Feedback loop

A loop which uses the output of a system to signal changes.

Negative feedback

A mechanism that reverses or counteracts a deviation, bringing the body to a stable equilibrium and shutting off the process that is affecting homeostasis to keep the system stable.

Vasodilation

A physiological response triggered by the brain when internal body temperature becomes too high, occurring alongside sweating to release heat.

Vasoconstriction

A physiological response triggered by the brain when internal body temperature becomes too low, occurring alongside shivering to generate heat.

Semi-permeable

The property of the cell membrane that allows certain molecules in while keeping certain molecules out, and vice-versa.

Aquaporin

A type of membrane protein that assists with moving water through the cell membrane during osmosis.

Active transport

A transport mechanism across the cell membrane that requires energy and relies on pumps to force molecules across.

Levels of biological organization

The hierarchy of structural organization arranged from smallest to largest: organelle, cell, tissue, organ, organ system, organism.

Conditions regulated for homeostasis

Three critical conditions that organisms must regulate to maintain homeostasis: body temperature, blood glucose (sugar) levels, and water/hydration.