Biology Diffusion Concepts Quiz

Diffusion Concepts

• Concentration Gradient: Refers to the variation in concentration of a substance between two areas, influencing the movement of molecules.
• Passive Transport: Process where materials move across cell membranes without the expenditure of energy, relying on natural concentration differences.
• Active Transport: Requires energy to transport materials in or out of a cell against their concentration gradient.

Types of Transport

• Passive Transport Types: Includes diffusion, facilitated diffusion, and osmosis, which do not require energy input.
• Simple Diffusion: Involves molecules moving from a region of higher concentration to one of lower concentration, seeking balance.
• Facilitated Diffusion: Similar to simple diffusion, but utilizes transport proteins to assist molecules moving down their concentration gradient without energy usage.

Mechanisms of Transport

• Equilibrium: Achieved when the distribution of molecules becomes uniform across a space, indicating balanced concentrations.
• Channel Protein: A specific type of transport protein aiding in the passage of ions and water across the cell membrane.
• Carrier Protein: Facilitates the transport of specific molecules, such as glucose, through the membrane.

Active Transport Methods

• Active Transport Types: Comprises endocytosis, exocytosis, and protein pumps, all of which necessitate energy to move substances.
• Transport Proteins: Encompass both channel and carrier proteins, essential for the selective movement of substances across cell membranes.

Molecular Characteristics

• Non-Polar Molecules: Substances like carbon dioxide and oxygen easily permeate the phospholipid bilayer via simple diffusion due to their hydrophobic nature.
• Polar Molecules: Examples include glucose, water, and ions, which cannot pass freely through the membrane and require assistance from transport proteins to traverse cell membranes.