Homeostasis and Cell Transport

These flashcards cover key vocabulary terms related to homeostasis and cell transport from Chapter 5 of Biology I.

Passive Transport

Substances that pass across the cell membrane without any input of energy by the cell.

Diffusion

The movement of molecules from an area of higher concentration to an area of lower concentration.

Concentration Gradient

The difference in the concentration of molecules across a distance.

Equilibrium

The concentration of molecules will be the same throughout the space the molecules occupy.

Osmosis

Water molecules diffuse across a cell membrane from an area of higher concentration to an area of lower concentration.

Hypotonic

A solution where solutes are lower outside the cell, causing water to move in.

Hypertonic

A solution where solutes are higher outside the cell, causing water to move out.

Isotonic

A solution where solutes are equal on both sides, causing water to move equally in and out.

Contractile Vacuole

Organelles that remove water in organisms living in hypotonic solutions.

Turgor Pressure

The pressure water exerts against the cell wall in a hypotonic solution.

Plasmolysis

The shrinking of a cell away from the cell wall in a hypertonic solution.

Cytolysis

The bursting of cells due to excess water intake.

Facilitated Diffusion

The transport of substances through a cell membrane along a concentration gradient with the aid of carrier proteins.

Carrier Protein

A protein that assists in the transport of substances across a cell membrane.

Ion Channels

Complexes of protein molecules in a cell membrane that form a pore through which ions can pass.

Sodium-Potassium Pump

A carrier protein that uses ATP to actively transport sodium ions out of a cell and potassium ions into the cell.

Exocytosis

The process by which a substance is released from the cell through a vesicle that fuses with the membrane.

Endocytosis

The process by which cells ingest external fluid, macromolecules, and large particles.

Pinocytosis

A type of endocytosis that involves the transport of solutes or fluids.

Phagocytosis

A type of endocytosis that involves the movement of large particles or whole cells.

Vesicle

A small cavity or sac that contains materials in a eukaryotic cell.

Active Transport

The movement of substances across the cell membrane against a concentration gradient, requiring energy.

Turgor

The state of being swollen or firm due to high fluid content.

Macrophage

A type of phagocyte that engulfs and digests cellular debris.

Semi-permeable Membrane

A membrane that allows certain molecules to pass while blocking others.

Active Transport

Movement of chemical substances against a concentration gradient, requiring cellular energy.

Cell Membrane Pumps

Special proteins embedded in the cell membrane that actively transport ions and molecules.

Cytosol

The liquid component inside cells where cellular processes occur.

Cell Wall

A structural layer surrounding some cells, providing protection and support.

Diffusion Rate

The speed at which molecules move from high to low concentration.

Osmolarity

A measure of solute concentration per unit of solvent volume.

Permeability

The ability of a membrane to allow substances to pass through.

Transport Proteins

Proteins that assist in the movement of substances across the cell membrane.