L112_H4_Membrane_Structure_function_SS

Membrane Structure

The arrangement of phospholipids and proteins that forms the boundary of cells.

Phospholipid Bilayer

A double layer of phospholipids that constitutes the plasma membrane, with hydrophilic heads and hydrophobic tails.

Hydrophilic Head

The water-attracting part of the phospholipid molecule.

Hydrophobic Tail

The water-repelling part of the phospholipid molecule.

Fluid Mosaic Model

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

Cholesterol

A type of lipid that stabilizes the structure of the cell membrane.

Glycoprotein

A molecule containing carbohydrates attached to proteins, involved in cell recognition and signaling.

Glycolipid

A molecule consisting of carbohydrates attached to lipids, found in cellular membranes.

Transport Proteins

Proteins that facilitate the movement of substances across a cell membrane.

Peripheral Proteins

Proteins that are bound to the surface of the membrane.

Integral Proteins

Proteins that span the entirety of the membrane, involved in transport and signal transduction.

Channel Proteins

Proteins that form water-filled channels allowing molecules to pass through the membrane.

Carrier Proteins

Proteins that change shape to transport specific substances across the membrane.

Active Transport

The movement of substances against their concentration gradient, requiring energy.

Sodium-Potassium Pump

An active transport system maintaining high sodium outside and high potassium inside the cell.

Endocytosis

The process by which cells absorb molecules by engulfing them in a vesicle.

Exocytosis

The process of vesicles fusing with the membrane to release their contents outside the cell.

Phagocytosis

A type of endocytosis where a cell engulfs large particles.

Pinocytosis

A type of endocytosis where a cell takes in liquid and small particles.

Receptor-Mediated Endocytosis

Endocytosis that occurs when specific molecules bind to receptors on the cell surface.

Signal Transduction

The process by which a cell responds to signals or stimuli from its environment.

Ligand-Receptor Interaction

The binding of a signaling molecule (ligand) to a specific receptor on the cell surface.

Cell-cell Recognition

The ability of cells to recognize and communicate with each other.

Cytoskeleton

A network of protein filaments and tubules that provide structural support and shape to the cell.

Extracellular Matrix (ECM)

A collection of extracellular molecules secreted by cells, providing structural and biochemical support.

Antigens

Substances that trigger an immune response, often found on the surface of pathogens.

Antibody

A protein produced by the immune system that binds specifically to an antigen.

Co-transport

A process where the transport of one substance indirectly drives the transport of another substance.

Uniporter

A membrane protein that transports a single type of molecule across the membrane.

Symporter

A membrane protein that transports two or more different molecules across the membrane in the same direction.

Antiporter

A membrane protein that transports two or more different molecules across the membrane in opposite directions.

Aquaporins

Channel proteins that facilitate the passage of water across cell membranes.

Concentration Gradient

A difference in the concentration of a substance across a space, influencing the movement of substances.

Hydrophobic Molecules

Non-polar molecules that can easily pass through the lipid bilayer of membranes.

Hydrophilic Molecules

Polar molecules that do not easily pass through the lipid bilayer of membranes.

Hypervariable Loops

Regions of an antibody's variable region that bind antigens with high specificity.

Complementarity Determining Regions (CDRs)

Specific sites in antibodies that determine the binding affinity and specificity for antigens.

Opsonization

The process by which pathogens are marked for destruction by immune cells.

CD4 Protein

A protein on the surface of T-helper cells that HIV binds to for infection.

A co-receptor on T-helper cells that HIV requires for entry.

CCR5 Co-Receptor

Lipid Layer

The hydrophobic interior of the cell membrane that acts as a barrier to polar molecules.

Fluidity of Membrane

The ability of the components within the membrane to move laterally, affecting membrane function.

Membrane Potential

The difference in charge across a membrane that affects cell function and signal transmission.

Cell Adhesion Molecules

Proteins that mediate the adhesion between cells and contribute to the formation of tissues.

Immunoglobulin

A type of antibody that plays a key role in the immune response.

Transmembrane Proteins

Proteins that span across the membrane, playing roles in transport and communication.

An immune response mechanism where antibodies bind to target cells and recruit immune cells to kill them.

Antibody-Dependent Cell-Mediated Cytotoxicity (ADCC)

Endocytosis Types

The three types are phagocytosis, pinocytosis, and receptor-mediated endocytosis.