Cell membranes

Chapter 5Genes and Development

TEM evidence of membranes.Color has been added for clarity.

Freeze-fracturing analysis of membranes

Green algae membrane

Plasma membrane of photosyntheticbacterium

Freeze-fracturing analysis of membranes

Membrane fluidity

Types of proteins in membranes

Anchoring of proteins (lipoproteins)

Transmembrane proteins

Bacteriorhodopsin7-transmembrane protein

Poresβ-barrel (β-pleated sheets)

Passive transport-Ion channels

Passive transport-stimulus turns on channel

Carrier proteins

Osmosis

Uniporter Symporter Antiporter

Active transport-Na+/K+ pump

Coupled transportNa+/K+ pump and Na+/glucose transporter

Bulk transport

Receptor mediatedendocytosis

Exocytosis