Chapter 1-7: Introduction to Transport Mechanisms

Flashcards covering key vocabulary related to cell membrane structure and transport mechanisms based on the lecture notes.

Lysosomes

Organelles that have six different enzymes with different functions, primarily responsible for 'cleanup work' by breaking down various substances.

Plasma Membrane

The outer boundary of a cell, primarily composed of phospholipids and proteins, crucial for regulating transport mechanisms.

Phospholipids

The main structural component of the plasma membrane, forming a bilayer with heads facing outward towards the extracellular and intracellular environments.

Integral Proteins

Proteins that extend throughout the plasma membrane (also called transmembrane proteins) and function as transporters or receptors.

Permeability

A characteristic of the plasma membrane, meaning that certain substances, such as very small uncharged particles like oxygen and carbon dioxide, can pass directly through it.

Concentration Gradient

A difference in the amount of a solute (substance such as sodium, chloride, or glucose) between the outside and inside of a cell.

Passive Transport

A transport process that does not require the cell to produce any energy (ATP) for substances to move across the plasma membrane, typically occurring as substances move down their concentration gradient.

Active Transport

A transport process that requires the cell to produce energy (ATP) for a substance to cross the plasma membrane, often moving against its concentration gradient (from a lower to a higher concentration).

Diffusion

The movement of molecules from an area of higher concentration to an area of lower concentration (down their gradient), aiming for an even distribution of the substance.

Osmosis

A special case of diffusion that involves the net movement of water molecules (a solvent) across a selectively permeable membrane, from a higher water concentration to a lower water concentration.

Isotonic Solution

A solution in which a cell is placed where there is an equal concentration of solute outside as inside the cell, resulting in no net gain or loss of water by the cell and maintenance of its normal shape.