biological membranes and transport (Ch. 11).ppt

Chapter 11 Biomembranes and Transport Across Biomembranes
A cell body
A celium
mitochondrion
A digestive vacuole
The endoplasmic reticulum
A secretory vesicle
1. Biomembranes anized, sheetlike assemblies consisting mainly of proteins and lipids
The functions carried out by membranes are diverse and indispensable for life.
Biomembranes give cells their individuality by separating them from the environment.
Biomembranes are highly selective permeability barriers with specific protein channels and pumps regulating the molecular and positions of the intracellular medium (transport across membranes).
Biomembranes control the flow of information between cells and their environment through specific receptors on the plasma membrane (signal transduction).
Eukaryotic cells have an extensive internal membrane system dividing cells into partments (forming anelles).