Cell Structure, Membrane Function, and Transport

Comprehensive vocabulary flashcards covering cell organelles, membrane structure, surface area-to-volume dynamics, transport mechanisms, tonicity, and vesicular processes.

Vacuole

A membrane-bound sac used for storage.

Food vacuole

A vacuole that stores food particles before digestion.

Central vacuole

A large plant-cell organelle that stores water and helps maintain turgor pressure.

Turgor pressure

Pressure created when water inside a plant cell pushes against the cell wall.

Cytoskeleton

A network of protein fibers that maintains cell shape, supports movement, and helps transport materials.

Microvilli

Tiny projections on cells that increase surface area for absorption.

Surface area-to-volume (SA:V) ratio

The relationship between a cell's outer area and internal volume; a higher ratio allows more efficient exchange of nutrients, oxygen, and wastes, as well as faster heat exchange.

Fluid mosaic model (Mosaic)

A description of the cell membrane indicating it contains different proteins and other molecules embedded throughout it.

Cholesterol

A membrane lipid component that helps maintain membrane fluidity and stability.

Membrane proteins

Proteins embedded in or attached to the cell membrane.

Channel proteins

Proteins that form passageways for specific substances.

Carrier proteins

Proteins that change shape to transport specific molecules.

Receptor proteins

Proteins that receive chemical signals.

Recognition proteins

Proteins that help cells identify one another.

Enzyme proteins

Proteins that speed up chemical reactions.

Adhesion proteins

Proteins that help cells attach to other cells or surfaces.

Bulk transport

The movement of large materials into or out of a cell using membrane-bound vesicles, requiring cellular energy to move and reshape the membrane.

Diffusion

The movement of individual molecules across or within areas, differing from bulk transport which uses vesicles.

Cell wall

An outer structure with pores that maintains cell structure and protects against hypotonic solutions by preventing excessive swelling and bursting.

Active transport

The movement of substances against their concentration gradient from low concentration to high concentration using energy (usually ATP) and transport proteins.

Sodium-potassium pump

A specific transport protein mechanism that serves as an example of active transport.

Proton pump

A transport protein mechanism that serves as an example of active transport.

Concentration gradient

A difference in the concentration of a substance between two areas.

Equilibrium

A state where concentrations are balanced and there is no net movement of a substance.

Hypertonic solution

A solution with higher solute concentration than the cell; water moves out of the cell, causing animal cells to shrink and plant cells to become plasmolyzed.

Isotonic solution

A solution with equal solute concentrations inside and outside the cell; animal cells maintain normal size while plant cells become flaccid.

Osmosis

The movement of water toward the side with higher solute concentration.

Osmoregulation

The process of maintaining proper water and solute balance.

Endocytosis

The process of bringing materials into a cell using vesicles.

Exocytosis

The process of releasing materials out of a cell using vesicles, such as hormones, neurotransmitters, or proteins.

Phagocytosis

A type of endocytosis where a cell engulfs large particles or solid materials, such as a white blood cell engulfing bacteria.

Pinocytosis

A type of endocytosis where a cell takes in extracellular fluid and dissolved substances.

Receptor-mediated endocytosis

A type of endocytosis where a cell takes in specific substances that bind to membrane receptors.