Cell Membrane Structure and Function

This set of flashcards focuses on vocabulary and key concepts related to cell membrane structure and function, transport mechanisms, metabolism, and energy generation processes.

Phosphatidylcholine

A molecule made up of choline, phosphate, glycerol, and two hydrocarbon chains, important for cell membrane structure.

Fluidity of the lipid bilayer

The ability of the bilayer to allow movement of its components, influenced by temperature and the structure of hydrocarbon tails.

Transport proteins

Proteins that assist in the movement of ions and molecules across the cell membrane, including channels and transporters.

Active transport

The process of moving molecules against their concentration gradient, requiring energy, commonly through ATP hydrolysis.

Passive transport

The movement of molecules across the membrane without the use of energy, occurring down the concentration gradient.

Osmosis

The diffusion of water across a selectively permeable membrane, often affecting cell volume based on solute concentration.

Membrane potential

The difference in electric charge across a membrane, essential for processes like nerve impulse transmission.

Gated ion channels

Channels that open or close in response to specific stimuli, such as voltage changes or ligand binding.

Cell cortex

A meshwork of proteins, primarily spectrin, located beneath the plasma membrane, providing structural support.

Sodium-potassium pump

An active transport mechanism that maintains cell membrane potential by pumping sodium out and potassium into the cell.

Electrochemical gradient

The combined effect of concentration gradient and electrical potential across the membrane that drives ion movement.

Chemiosmotic coupling

The process linking electron transport and ATP synthesis in mitochondria, based on the proton gradient.

Co-transport

A form of active transport that simultaneously moves two different molecules across the membrane.

Excitatory synapse

A synapse that increases the probability of a postsynaptic action potential by allowing positive ions to enter the cell.

FRAP (Fluorescence Recovery After Photobleaching)

A technique used to study the lateral mobility of membrane proteins by measuring the recovery of fluorescence.

Endocytosis

The process by which cells engulf external substances, forming vesicles to transport them into the cell.

Glycolysis

A metabolic pathway that breaks down glucose to produce energy, resulting in pyruvate, ATP, and NADH.

Citric Acid Cycle

A key metabolic pathway that converts acetyl CoA into CO2 and water, generating high-energy carriers like NADH and FADH2.

Brown fat cells

Cells that use uncoupling proteins to dissipate energy as heat rather than converting it to ATP, important for thermogenesis.

ATP synthase

An enzyme that synthesizes ATP from ADP and inorganic phosphate, powered by the flow of protons across the mitochondrial membrane.

Coupled transport

The simultaneous transport of different molecules across a membrane, which can be symport or antiport.