While cholesterol has a bad reputation for clogging up arteries and causing heart disease, this fatty molecule is an essential part of all cell membranes. Scientists have now found to their surprise that cholesterol may also regulate when and where nerve cells in the brain form the vital junctions known as synapses. * Cholesterol is a waxy fat that is present in all human beings. Two sources contribute to the amount of cholesterol in the human …showed first 75 words of 1815 total…

…showed last 75 words of 1815 total…exercise appears to correlated with low levels of LDL and high levels of HDL. RELATED DEFINITIONS: * artery RELATED ESSAYS: * Cholesterol (essay) A sterol (fat derivative) found in animal cells. It occurs in bile, blood cells, cell membranes, blood plasma, and egg yolk. It can accumulate in the gall bladder as gallstones, and an elevated level of cholesterol in the blood is thought to be a contributory cause of hardening and narrowing of the arteries (arteriosclerosis).