Biology - Understanding the Fluid Mosaic Model of Cell Membrane

Understanding the Fluid Mosaic Model of Cell Membrane

Fluid Mosaic Model

Describes cell membrane structure and function.

Cell Membrane

Holds cell components and regulates substance entry.

Phospholipids

Molecules forming bilayer with hydrophilic heads.

Hydrophilic

Attracted to water; phosphate head property.

Hydrophobic

Repels water; fatty acid tail property.

Self Assembly

Phospholipids organize into bilayers spontaneously.

Cholesterol

Steroid regulating membrane fluidity and permeability.

Integral Proteins

Proteins embedded in the phospholipid bilayer.

Transport Proteins

Facilitate movement of larger molecules across membrane.

Polar Molecules

Uneven electron distribution; interacts with water.

Nonpolar Molecules

Even electron distribution; repels water.

Peripheral Proteins

Proteins attached to membrane surface, aiding communication.

Membrane Fluidity

Movement of membrane components; influenced by temperature.

Temperature Effect

Affects phospholipid movement and spacing.

Saturated Fatty Acids

Chains with single bonds; pack tightly.

Unsaturated Fatty Acids

Chains with double bonds; create kinks.

Semi Permeable Membrane

Allows selective passage of substances.

Small Nonpolar Molecules

Easily pass through lipid bilayer (e.g., O2).

Small Polar Molecules

Can cross bilayer but with difficulty (e.g., H2O).

Large Nonpolar Molecules

Slowly pass through bilayer (e.g., carbon rings).

Large Polar Molecules

Require transport proteins to cross (e.g., glucose).

Ions

Charged particles needing transport proteins to cross.

Alzheimer's Disease

Neurodegenerative disease linked to membrane dysfunction.

Plaque Formation

Blocks neuron communication, contributing to Alzheimer's.

Cell Membrane Function

Regulates nutrient uptake and waste export.

Mosaic Pattern

Diverse molecules distributed across the membrane.

Fluid Movement

Molecules move in two dimensions within membrane.

Environmental Conditions

Influence cholesterol's role in membrane stability.

Kinks in Fatty Acids

Increase space between phospholipids, enhancing fluidity.