Cell Membrane Structure and Function

Boundary between the cell and its environment, controlling substance movement and maintaining cell homeostasis.

Model describing the cell membrane as a fluid-like mosaic of lipids, proteins, and carbohydrates.

Foundational structure of the cell membrane, composed of two layers of phospholipids.

Amphipathic molecules with a hydrophilic head and hydrophobic tail, forming the lipid bilayer.

Membrane proteins embedded in the lipid bilayer, potentially extending through both layers.

Membrane proteins on the inner or outer surface of the lipid bilayer but not embedded within.

Maintenance of stable conditions within the cell.

Lipid that modulates membrane fluidity and stability, interspersed in the lipid bilayer.

The cell membrane acts as a barrier between the cell's interior and its external environment. It controls the movement of substances in and out of the cell, ensuring the cell's internal environment stays stable (homeostasis).

The Fluid Mosaic Model explains how the cell membrane is structured. It's not a rigid wall, but a fluid-like tapestry of lipids, proteins, and carbohydrates constantly moving and interacting.

The lipid bilayer forms the base of the cell membrane. It's made of two layers of phospholipids, with their tails facing inwards and heads outwards.

Phospholipids are special molecules with two parts: a water-loving 'head' and water-hating 'tails'. The 'heads' face outwards, while the 'tails' form the inner layer, creating a barrier.

Cholesterol, a type of lipid, is like a stabilizer in the membrane. It helps the membrane stay fluid and flexible, but also keeps it from getting too loose.

Glycolipids are lipids with sugar molecules attached. They help cells recognize each other and communicate.

Integral proteins are embedded within the lipid bilayer. They might extend through both layers, acting as tunnels or channels.

Peripheral proteins are attached to the membrane, either on the inside or outside, but don't go through the lipid bilayer.

Carbohydrates are the third component, acting like cell identification markers. They help cells 'talk' to each other and bind to other molecules.

It's the ability of a cell to maintain stable conditions inside, despite external changes. Like keeping the temperature, pH, and nutrient levels in an optimal range for survival.