Cell Transport and Homeostasis Vocabulary

Comprehensive vocabulary flashcards based on Unit 2 lecture notes covering cell membrane structure, transport mechanisms, and osmotic solutions.

Homeostasis

A process where a living thing keeps its internal environment stable and balanced, no matter what is happening in the outside environment.

Cell Membrane

The protective outer lipid bilayer barrier of all cells that regulates and controls what enters and exits the cell to maintain homeostasis.

Selective Permeability

The ability of a cell membrane to regulate what molecules enter and leave the cell, letting some pass through easily while blocking others.

Phospholipid

The basic building block of the cell membrane, which is a special fat molecule with a water-loving head and two water-fearing tails that line up in two layers.

Hydrophilic

Describing molecules, such as the heads of phospholipids, that are water-loving, attracted to water, and dissolve in it easily.

Hydrophobic

Describing molecules, such as the tails of phospholipids or oils, that are water-fearing, repel water, and will not mix with it.

Solute

The substance that is being dissolved in a solution, such as Kool aid Powder or sugar.

Solvent

The substance that does the dissolving in a solution, such as water.

Solution

A mixture composed of a solute dissolved in a solvent, such as a Kool aid drink.

Concentration Gradient

Occurs when a substance is more concentrated in one area than another.

Passive Transport

The movement of materials across the cell membrane from an area of high concentration to low concentration without using cellular energy ($\text{ATP}$).

Active Transport

The movement of materials across the cell membrane against the concentration gradient from low concentration to high concentration, requiring cellular energy ($\text{ATP}$).

Diffusion

A type of passive transport where small particles spread out evenly on their own, moving from an area of high concentration to an area of low concentration.

Facilitated Diffusion

A type of passive transport where small or large molecules that cannot directly diffuse across the membrane pass through a channel protein.

Osmosis

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

Protein Channel

A membrane protein that creates continuous, water-filled pores in the lipid bilayer, allowing molecules (primarily specific ions) to diffuse passively down their concentration gradient.

Protein Pump

A specific type of protein in the cell membrane that performs active transport by using energy ($\text{ATP}$) to move substances against their concentration gradient.

Sodium Potassium Pump

A specific protein in the cell membrane that uses active transport (energy) to pump sodium ions out of the cell and pull potassium ions into the cell.

Endocytosis

An active transport process where the cell membrane wraps around a large particle outside the cell, pinches off, and brings it inside the cell using a bubble called a vesicle.

Exocytosis

An active transport process where a vesicle inside the cell fuses with the cell membrane to spit out or release large waste and materials outside the cell.

Hypertonic Solution

A solution where the amount of solute outside the cell is higher than inside, causing water to move out of the cell and the cell to shrink or shrivel.

Hypotonic Solution

A solution where the amount of solute outside the cell is lower than inside, causing water to move into the cell and the cell to swell or burst.

Isotonic Solution

A solution where the amount of solute outside the cell is equal to the inside, causing water to move both in and out at an equal rate with no change to the cell.

Plasmolyzed

The state of a plant cell when it has shriveled due to losing water in a hypertonic solution.

Turgid

The normal, swollen state of a plant cell when placed in a hypotonic solution.

Lysed

The state of an animal cell when it swells and bursts after being placed in a hypotonic solution.

Flaccid

The state of a plant cell when placed in an isotonic solution where water enters and exits at an equal rate.

Excretion

One of the key reasons cell transport is important, defined as moving things like waste out of the cell.

Gas Exchange

A vital biological process facilitated by cell transport that regulates how organisms move gases across cell membranes.