SA Medical - General Medicine And Imaging of Disease

The cell membrane enables separation of electrical charge in the body.  The input of energy to transport ions across the membrane has created an electrical gradient - negative inside and positive on the outside Active transport of ions across the cell membrane also creates a chemical concentration gradient Electrical + concentration gradient = electrochemical gradient Osmotic equilibrium is maintained because water moves freely across the membrane. Resting membrane potential difference ECF = 0, ICF = -ve

Diagram of a typical  animal  ( eukaryotic ) cell, showing subcellular components. Organelles : (1)  nucleolus (2)  nucleus (3)  ribosome (4)  vesicle (5)  rough endoplasmic reticulum  (ER) (6)  Golgi apparatus (7)  Cytoskeleton (8)  smooth endoplasmic reticulum (9)  mitochondria (10)  vacuole (11)  cytoplasm (12)  lysosome (13)  centrioles  within  centrosome Eukaryotic  cells are about 15 times wider than a typical prokaryote and can be as much as 1000 times greater in volume.  Organisation of the Cell. The nucleus and the cytoplasm are separated by the nuclear membrane, The different substances that make up the cell are collectively called the protoplasm. The protoplasm is composed of: Water: 70 to 85% Electrolytes Na,K, Cl, HCO3, Ca, Mg, PO4 Proteins - 10 to 20% -  Structural proteins and Globular proteins (enzymes) Lipids - 2% - Phospholipids, cholesterol, triglycerides, and neutral fats.   Carbohydrates - 1% total body, but 3% of Muscles and 6% of Liver cells. S