Membrane Dynamics

A collection of vocabulary flashcards covering key terms and concepts related to membrane dynamics and transport processes in biological systems.

Membrane Dynamics

The study of the functions and behaviors of biological membranes.

Cystic Fibrosis

A genetic disorder caused by a deletion in the CFTR gene, characterized by mucus buildup.

CFTR gene

Cystic Fibrosis Transmembrane Conductance Regulator gene, associated with cystic fibrosis.

Homeostasis

The maintenance of a stable internal environment in an organism.

Osmosis

The movement of water across a membrane in response to a concentration gradient.

Diffusion

The passive process of moving molecules from a region of higher concentration to one of lower concentration.

Tonicity

The measure of the effective osmotic pressure gradient of two solutions separated by a semipermeable membrane.

Hydrophilic

Water-attracting substances that dissolve in water.

Hydrophobic

Water-repelling substances that do not easily dissolve in water.

Lipophilic

Substances that can dissolve in lipids and thus cross the lipid cell membrane.

Endocytosis

The process by which cells internalize substances from their external environment.

Phagocytosis

A type of endocytosis where cells engulf large particles, forming phagosomes.

Exocytosis

The process through which a cell expels materials by vesicle fusion with the plasma membrane.

Facilitated Diffusion

A process that uses transport proteins to move substances across a cell membrane down their concentration gradient.

Active Transport

The movement of molecules across a membrane against their concentration gradient, requiring energy.

Primary Active Transport

Directly uses energy, typically from ATP, to transport molecules against their gradient.

Secondary Active Transport

Uses the energy from the movement of one molecule down its gradient to push another molecule against its gradient.

Membrane Proteins

Proteins that perform various functions at the cell membrane, including transport, signaling, and structural roles.

Channel Proteins

Proteins that create water-filled pores in the membrane, allowing selective passage of ions or molecules.

Carrier Proteins

Proteins that bind to molecules and change shape to transport them across the membrane.

Concentration Gradient

The difference in the concentration of a substance across a distance.

Electrochemical Gradient

The combined difference in concentration and electrical charge across a membrane.

Resting Membrane Potential

The voltage difference across the membrane of a resting cell, typically around -70mV.

Na+/K+ ATPase

An active transport mechanism that pumps sodium out and potassium into the cell, crucial for maintaining the resting membrane potential.

Transport Maximum

The point at which all available transporters are occupied, and transport rate cannot increase.

Saturation

When all carrier proteins are fully occupied with substrates, limiting transport rate.

Isotonic

A solution with the same solute concentration as another solution.

Hypertonic

A solution that has a higher concentration of solutes than another solution.

Hypotonic

A solution that has a lower concentration of solutes than another solution.

Osmolarity

A measure of solute concentration defined as the number of osmoles of solute per liter of solution.

Vesicles

Small membrane-bound sacs that transport substances within a cell.

Ligand-gated Channels

Channels that open or close in response to binding of a chemical messenger.

Voltage-gated Channels

Channels that open or close in response to changes in membrane potential.

Mechanically gated Channels

Channels that respond to mechanical forces, resulting in membrane deformation.

Receptor-mediated Endocytosis

A process where cells bring in specific molecules by engulfing them after they bind to a receptor.

Transepithelial Transport

Transport of substances across an epithelial layer, involving both active and passive transport mechanisms.

Caveolae

Small, flask-shaped invaginations in the cell membrane, involved in endocytosis.

Phagosomes

Large vesicles that form during phagocytosis.

Macromolecules

Large complex molecules like proteins, nucleic acids, or polysaccharides.

Chemical Disequilibrium

When the concentrations of solutes are not evenly distributed across compartments in the body.

Electrical Disequilibrium

The condition where there is a difference in charge distribution across a membrane.

Mass Balance

The principle stating that the total mass of a substance must remain constant, with gains and losses balanced.

Equilibrium

A state in which opposing forces or influences are balanced.

What is simple diffusion?

Simple diffusion is the passive movement of molecules from an area of higher concentration to an area of lower concentration without the need for energy.

What is facilitated diffusion?

Facilitated diffusion is the process of passive transport of molecules across a biological membrane via specific transmembrane integral proteins.

What is primary active transport?

Primary active transport is the movement of molecules across a membrane against their concentration gradient, using energy directly from ATP.

What is secondary active transport?

Secondary active transport is the movement of molecules across a membrane against their concentration gradient, driven by the electrochemical gradient established by primary active transport.

What is diffusion?

Diffusion is the process by which molecules spread from areas of high concentration to areas of low concentration.

What are the seven properties of diffusion?

1. Movement is from high to low concentration. 2. It occurs in gases, liquids, and solids. 3. Temperature affects the rate of diffusion. 4. Molecules diffuse independently. 5. Larger molecules diffuse slower. 6. It continues until equilibrium is reached. 7. It can occur across membrane barriers.

What is osmotic equilibrium?

Osmotic equilibrium is the state in which the concentration of solutes is equal on both sides of a semipermeable membrane, resulting in no net movement of water.

What is chemical equilibrium?

Chemical equilibrium is the state in a reversible chemical reaction where the rates of the forward and reverse reactions are equal, resulting in constant concentrations of reactants and products.

What is electrical equilibrium?

Electrical equilibrium is the condition in which the net electric charge within a system is balanced, meaning there is no net movement of charge.

What is a sodium-glucose linked transporter (SGLT)?

A sodium-glucose linked transporter (SGLT) is a type of protein that facilitates the active transport of glucose into cells by using the sodium gradient established by the sodium-potassium pump.

How does the sodium-glucose linked transporter work?

The SGLT works by co-transporting sodium ions into the cell along with glucose, utilizing the energy from the sodium gradient to move glucose against its concentration gradient.

Where is the sodium-glucose linked transporter primarily found?

The sodium-glucose linked transporter (SGLT) is primarily found in the intestines and kidneys, where it plays a critical role in glucose absorption