One of the characteristic features of a living cell is that it controls the exchange of electrically charged ions across the cell membrane and therefore the electrical potential of its interior relative to the exterior. This Scholarpedia page is a basic introduction into the mechanisms underlying this process.
Here are the ranges for total cholesterol in adults: 1  Normal: Less than 200 mg/dL. 2  Borderline high: 200 to 239 mg/dL. 3  High: At or above 240 mg/dL.
Total cholesterol should be 5.0 millimoles per litre (mmol/L) or lower. The average in the UK is actually around 5.5 mmol/l for men and 5.6 mmol/l for women. Cholesterol numbers are used to calculate the overall risk of coronary heart disease.