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.
When measuring total cholesterol levels, low-density lipoprotein (LDL), high-density lipoprotein (HDL), and triglycerides are used in the measurement. For adults, standard cholesterol levels are: 1  Less than 200 mg/dL is desirable. 2  Between 200 - 239 mg/dL is considered borderline. 3  Over 240 mg/dL is considered high.