Membranes and Receptors - Session 2

<p>8 nm (B)</p> Signup and view all the answers

<p>It defines the cell by controlling traffic in and out based on polarity. (B)</p> Signup and view all the answers

<p>Ionic concentration differences created by primary active transport (C)</p> Signup and view all the answers

<p>Move two molecules in opposite directions (C)</p> Signup and view all the answers

<p>Transport two molecules in the same direction (C)</p> Signup and view all the answers

<p>Cotransport (A)</p> Signup and view all the answers

<p>They create a gradient of hydrogen ions that drives nutrient transport. (A)</p> Signup and view all the answers

<p>Secondary active transport using a symporter (D)</p> Signup and view all the answers

<p>Change in the configuration of the carrier protein (B)</p> Signup and view all the answers

<p>They facilitate the transport of specific solutes across the cell membrane. (D)</p> Signup and view all the answers

<p>Specific channels permit certain materials across (D)</p> Signup and view all the answers

<p>Transport water across the cell membrane (B)</p> Signup and view all the answers

<p>Involves movement from high to low concentration (C)</p> Signup and view all the answers

<p>Facilitated diffusion requires transport proteins (C)</p> Signup and view all the answers

<p>Conformational change in a protein pump (D)</p> Signup and view all the answers

<p>Primary active transport (A)</p> Signup and view all the answers

<p>It changes shape to allow solutes to pass (B)</p> Signup and view all the answers

<p>Diffusion of water through a semi-permeable membrane (D)</p> Signup and view all the answers

<p>They transport substances against concentration gradients (D)</p> Signup and view all the answers

<p>It occurs until equilibrium is reached (D)</p> Signup and view all the answers

The cell membrane acts as a barrier, controlling the movement of substances into and out of the cell. It allows some substances to pass through more easily than others.

The cell membrane is composed of a phospholipid bilayer. The head of the phospholipid is hydrophilic, attracted to water, while the tail is hydrophobic, repelled by water.

Hydrophilic molecules, such as water and sugars, have a hard time crossing the cell membrane because the hydrophobic tails of the phospholipids repel them.

Hydrophobic molecules, like lipids, can easily pass through the cell membrane because they can interact with the hydrophobic tails of the phospholipids.

The cell membrane is very thin, only 8 nanometers thick, which makes it a highly selective barrier.

The movement of molecules from an area of high concentration to an area of low concentration. This process is passive, meaning it does not require energy.

A type of diffusion where molecules pass through specific protein channels embedded in the cell membrane. This process is also passive.

The movement of water across a selectively permeable membrane from a region of high water concentration to a region of low water concentration.

The movement of molecules across a cell membrane against their concentration gradient. This requires energy, usually in the form of ATP.

A type of active transport where the energy source to move molecules across the membrane is directly from the breakdown of ATP.

A protein that spans the cell membrane, creating a channel that allows specific molecules to pass through.

A protein channel that allows water molecules to pass through the cell membrane.

A protein channel that allows protons (H+) to pass through the cell membrane.

The ability of a cell membrane to allow certain molecules to pass through while preventing others.

A change in the shape of a protein, often used for transporting molecules across a membrane.

Energy derived from pre-existing concentration differences across a membrane, established by primary active transport.

Transports one molecule at a time across the membrane.

Moves two molecules in the same direction across the membrane.

Moves two molecules in opposite directions across the membrane.

The movement of one solute indirectly drives the transport of other solutes across the membrane.

A specific type of cotransport where both solutes move in the same direction.

A specific type of cotransport where two solutes move in opposite directions.