Cell Transport

Front

Homeostasis Noun

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[hoh-mee-oh-stay-sis]

Back

Homeostasis

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A state of relatively constant internal physical and chemical conditions that an organism or cell maintains to function properly.

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Example: This diagram shows how red blood cells transport oxygen from the lungs to body cells, a continuous cycle that maintains stable oxygen levels (homeostasis).

Front

Passive Transport Noun

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[pas-iv trans-port]

Back

Passive Transport

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The movement of molecules across the cell membrane from a region of higher concentration to lower concentration without using cellular energy.

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Example: This diagram shows molecules moving from a high concentration area (extracellular fluid) to a low concentration area (cytoplasm) across the cell membrane without energy.

Front

Diffusion Noun

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[dih-fyoo-zhun]

Back

Diffusion

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The process by which particles move from an area of higher concentration to an area of lower concentration.

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Example: This diagram shows dye molecules moving from a high concentration area to a low concentration area in water, eventually spreading out evenly to reach equilibrium.

Front

Equilibrium Noun

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[ee-kwuh-lib-ree-uhm]

Back

Equilibrium

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The state reached when the concentration of a substance is the same on both sides of a cell membrane.

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Example: Particles move across a cell membrane from a high concentration area to a low concentration area until they are evenly distributed, reaching a state of equilibrium.

Front

Facilitated Diffusion Noun

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[fuh-sil-i-tey-tid dih-fyoo-zhun]

Back

Facilitated Diffusion

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The process where molecules that cannot directly diffuse across the membrane instead pass through special protein channels without energy use.

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Example: Molecules move from a high concentration area to a low concentration area across the cell membrane by passing through a specific protein channel.

Front

Osmosis Noun

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[oz-moh-sis]

Back

Osmosis

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The diffusion of water molecules through a selectively permeable membrane from a high to a low water concentration area.

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Example: Water molecules move across a semi-permeable membrane from an area of high concentration to low concentration, while larger salt molecules cannot pass through.

Front

Aquaporin Noun

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[ak-wuh-paw-rin]

Back

Aquaporin

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Water channel proteins embedded in the cell membrane that facilitate the rapid passage of water molecules into or out of cells.

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Example: This diagram shows an aquaporin, a special protein channel embedded in the cell membrane, that allows water molecules to easily pass through it.

Front

Isotonic Adjective

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[ahy-soh-ton-ik]

Back

Isotonic

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Describes a solution where the concentration of solutes is the same inside and outside the cell, causing no net water movement.

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Example: In an isotonic solution, water moves into and out of an animal cell at an equal rate, allowing the cell to maintain its normal shape.

Front

Hypertonic Adjective

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[hahy-per-ton-ik]

Back

Hypertonic

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Describes a solution that has a higher solute concentration than the cell, causing water to move out of the cell.

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Example: In a hypertonic environment, the cell has a lower solute concentration, causing water to move out and the cell to shrink or shrivel.

Front

Hypotonic Adjective

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[hahy-poh-ton-ik]

Back

Hypotonic

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Describes a solution that has a lower solute concentration than the cell, causing water to move into the cell.

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Example: In a hypotonic environment, there is a lower concentration of solutes outside the cell, causing water to move into the cell.