Specialized Exchange Surfaces in Biology

These flashcards cover key concepts related to specialized exchange surfaces, gas exchange mechanisms, and related physiological processes.

Surface Area to Volume Ratio

The ratio that describes how much surface area a cell has in relation to its volume; larger SA:V ratios allow for more efficient exchange of materials.

Diffusion

The process by which molecules move from an area of high concentration to an area of low concentration.

Single-celled Organisms

Organisms that consist of only one cell and generally have a high surface area to volume ratio that allows substances to be exchanged efficiently via diffusion.

Multicellular Organisms

Organisms composed of multiple cells that have a lower surface area to volume ratio than single-celled organisms, requiring specialized exchange surfaces for efficient gas exchange.

Metabolic Rate

The rate at which an organism converts food into energy; higher metabolic rates are typically found in smaller organisms.

Alveoli

Tiny air sacs in the lungs where gas exchange occurs; they have thin walls and are surrounded by a network of capillaries.

Counter-current Exchange System

A mechanism in fish gills where blood flows in the opposite direction to water, maintaining a concentration gradient for oxygen absorption.

Ciliated Epithelium

A type of tissue found in the trachea that has hair-like structures (cilia) that help to sweep mucus and trapped particles away from the lungs.

Bronchi

The major air passages that branch from the trachea and direct air into the lungs.

Spirometer

An apparatus used to measure airflow and breathing volumes in the lungs.

Cell Membrane

The semi-permeable membrane surrounding the cell, controlling the movement of substances in and out.

Osmosis

The diffusion of water across a selectively permeable membrane from an area of low solute concentration to an area of high solute concentration.

Endocytosis

The process by which cells engulf substances from their exterior environment.

Exocytosis

The process where cells expel materials in vesicles that fuse with the cell membrane.

Facilitated Diffusion

A form of passive transport that uses transport proteins to move molecules across the cell membrane.

Active Transport

The movement of molecules across a cell membrane into a region of higher concentration, requiring energy.

Homeostasis

The process by which biological systems maintain stability while adjusting to conditions that are optimal for survival.

Transport Proteins

Proteins that assist in the movement of ions and molecules across the cell membrane.

Aquaporins

Channel proteins specifically designed to transport water molecules across cell membranes.

Photosynthesis

The process by which green plants and some other organisms use sunlight to synthesize foods with the help of chlorophyll.