Plasma membrane

Compartmentalisation

Specific enzymes and substrates can be kept in a specific place so specific activities can occur in each organelle.

Intracellular membrane

Membrane inside of a cell

The fluid Mosaic Model

The membrane is able to move. Proteins float in a sea of phospholipids. Simplified version of real life.

Phosphate head

Hydrophilic

Fatty acid tails

Hydrophobic

Phospholipid bilayer

Layer of multiple phospholipids

interstitial Fluid (Extracellular)

Outside of the cell

Cytosolic Fluid (Intracellular)

Inside of the cell

Non-polar

No charge

Integral proteins

Span the entire width of the membrane

Peripheral proteins

Don’t span the entire width of the membrane

Glycoprotein

When a chain of sugars are attached to a protein (act as chemical flags-antigens)

Glycolipid

When a chain of sugars are attached to a phospholipid (act as chemical flags-antigens)

Cholesterol (eukaryotes only)

Steroid lipid- regulates the stability of the membrane

Transport proteins

Allows substances to pass through or across