Untitled Quiz

Separates the cell from its surroundings, controlling traffic of substances in and out, and exhibiting selective permeability.

The most abundant lipid in the plasma membrane, an amphipathic molecule with both hydrophilic and hydrophobic regions.

A model describing the plasma membrane as a mosaic of proteins embedded in a fluid phospholipid bilayer.

The ability of the plasma membrane to regulate what enters and leaves the cell.

The ability of the membrane to change shape and allow movement of components.

The part of a molecule that repels water.

The part of a molecule that attracts water.

Embedded into the lipid bilayer of the plasma membrane, proteins play a crucial role in regulating the passage of molecules, cell recognition, and cell signaling.

A cell's ability to distinguish one type of neighboring cell from another.

Carbohydrates attached to lipids (glycolipids) or proteins (glycoproteins) on the cell membrane.

Surface molecules (often carbs or proteins) that allow cells to recognize each other.

Membrane proteins that connect adjacent cells through junctions.

Intercellular connections that allow cytoplasmic channels between cells.

Intercellular connections that prevent leakage of extracellular fluid.

Membrane proteins that connect to the cell's internal framework (cytoskeleton).

The process in which plant cells lose water and shrink due to a hypertonic environment, resulting in wilting.

Movement of substances across a membrane from an area of high concentration to an area of low concentration, without energy expenditure.

A type of passive transport where molecules move across a membrane with the help of transport proteins.

Membrane proteins that facilitate the movement of specific molecules across the cell membrane.

A type of transport protein that acts as a tunnel, allowing specific molecules or ions to pass through the membrane.

Water channel proteins that facilitate the rapid movement of water molecules across cell membranes.

A transmembrane protein channel that allows specific ions to pass through the membrane.

Ion channels that can open or close in response to a specific stimulus like a chemical, electrical, or mechanical change.

The ability of a solution surrounding a cell to cause that cell to gain or lose water.

A solution with the same solute concentration as the inside of a cell. No net water movement occurs.

A solution with a higher solute concentration than the inside of a cell. Water leaves the cell.

A solution with a lower solute concentration than the inside of a cell. Water enters the cell.

The cell will swell and lyse (burst) because water moves into the cell faster than it leaves.

The cell will lose water to its environment, shrink, and potentially die.

The cell swells but does not burst. It becomes turgid (firm), due to the cell wall.

The cell loses water, the vacuole shrinks, the plasma membrane pulls away from the cell wall, and the cell becomes flaccid (wilts).

These channels open in response to physical deformation of the receptor, like pressure or touch. They're found in sensory receptors of the skin and ear.

Cystic fibrosis is caused by a mutated gene that leads to defective or missing chloride channel proteins. These proteins are essential for the proper movement of water and salt across cell membranes.

The defective chloride channels in cystic fibrosis result in thicker and stickier mucus in the lungs, pancreas, and other organs. This mucus buildup can lead to infections and blockages.

Cystinuria is caused by defects in the carrier proteins that transport cystine (an amino acid) across the membranes of kidney cells. This leads to cystine buildup in the urine, forming crystals and stones.

Facilitated diffusion is a form of passive transport where carrier proteins help small hydrophilic molecules, like glucose and amino acids, cross the cell membrane. This process doesn't require energy.

Carrier proteins change shape when a solute binds to their binding site, allowing the transported molecule to be released across the membrane. This process doesn't require energy.

The glucose transporter is a specific carrier protein that binds to glucose, changes shape, and releases glucose into the cell. This process is an example of facilitated diffusion.

In cystinuria, the defective carrier proteins in the kidneys prevent cystine from being reabsorbed into the bloodstream. This leads to an increase in cystine in the urine, which can form crystals and stones.

A transport protein that generates voltage across a membrane by creating an uneven distribution of ions.

An electrogenic pump found in animal cells that pumps 3 Na+ ions out of the cell for every 2 K+ ions pumped in, creating a concentration gradient and a membrane potential.

An electrogenic pump found in plants, fungi, and bacteria that pumps protons (H+) out of the cell, creating a proton gradient and a membrane potential.

A system where the movement of one solute down its concentration gradient provides energy for the transport of another solute against its gradient.

A type of cotransport in plants where the movement of protons (H+) down its concentration gradient provides energy for the uptake of sucrose against its gradient.

Active transport requires energy expenditure, which is provided by ATP. It also relies on carrier proteins to move molecules against their concentration gradient.

Active transport allows cells to maintain an internal concentration of small solutes that differ from the environment, enabling them to function optimally.