PLASMA MEMBRANE
At the cells of the target organ, the hormone acts as a “first or extracellular messenger”, binding to a specific receptor site for that hormone on the plasma membrane. The hormone – receptor complex activates the enzyme adenylate cyclase in the membrane. The activated
LIFE WITHIN A SINGLE PLASMA MEMBRANE Protozoa have unicellular (cytoplasmic) organization. But they are not simple organisms. Often, they are more complex than any particular cell in higher organisms. Some individual protozoans come together to form colonies. The individuals in a colony are not
greater than it inside. Filtration Hydrostatic pressure forces small molecules across selectively permeable membranes from areas of higher pressure to areas of lower pressure. A frog’s blood pressure forces water and dissolved wastes into the kidney tubules during urine formation. Active
The plasma membrane surrounds the cell. Chemically plasma membrane is composed of: Protein: 60 to 80% Phospholipids: 20 to 40 % Cholesterol in small amount Carbohydrates in small amount Fig: Fluid mosaic model of plasma membrane STRUCTURE OF CELL MEMBRANE S. onathan Singer and
