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.
To calculate your cholesterol ratio, divide your high-density lipoprotein (HDL, or good) cholesterol number into your total cholesterol number. An optimal ratio is less than 3.5-to-1. A higher ratio means a higher risk of heart disease. Non-HDL cholesterol, as its name implies, simply subtracts your HDL cholesterol number from your total cholesterol number. So it contains all the bad types of cholesterol. An optimal level of non-HDL cholesterol is less than 130 milligrams per deciliter (mg/dL), or 3.37 millimoles per liter (mmol/L).