SciTech Revel

Cholesterol and Heart Disease Cholesterol is probably the best-known steroid because of the widely publicized correlation between cholesterol levels in the blood and heart disease. Cholesterol is synthesized in the liver and is present in almost all body tissues. It is also found in many foods, but we do not require cholesterol in our diet because the body can synthesize all we need. A diet high in cholesterol can lead to high levels of cholesterol in the bloodstream, and the excess can accumulate on the walls of arteries, restricting the flow of blood. This disease of the circulatory system is known as atherosclerosis and is a primary cause of heart disease. Cholesterol travels through the bloodstream packaged in particles that are classified according to their density. Low-density lipoprotein (LDL) particles transport cholesterol from the liver to other tissues. Receptors on the surfaces of cells bind LDL particles, allowing them to be brought into the cell so it can use...

Drugs Bind to Their Receptors Many drugs exert their physiological effects by binding to specific sites, called receptors , on the surface of certain cells  . A drug binds to a receptor using the same kinds of bonding interactions—van der Waals interactions, dipole–dipole interactions, hydrogen bonding—that molecules use to bind to each other. The most important factor in the interaction between a drug and its receptor is a snug fit. Therefore, drugs with similar shapes and properties, which causes them to bind to the same receptor, have similar physiological effects. For example, each of the compounds shown here has a nonpolar, planar, six-membered ring and substituents with similar polarities. They all have anti-inflammatory activity and are known as NSAIDs (non-steroidal anti-inflammatory agents). Salicylic acid has been used for the relief of fever and arthritic pain since 500 b.c. In 1897, acetylsalicylic acid (known by brand names such as Bayer Aspirin, Bufferin,...

Hey there today I was just thinking that actually what happens when a person drinks alcohol. So, let’s get started… When a person drinks alcohol it is first absorbed in our oesophagus after which it is completely absorbed in small intestine where it is acted upon by enzymes of liver. Basically, alcohol is digested by two enzymes “alcohol dehydrase” then by “aldehyde dehydrase” 1    1.)     Alcohol dehydrase digests alcohol by taking out water molecule out of it and converting it into formaldehyde. 2     2.)     Aldehyde dehydrase also takes out water from formaldehyde and breaks formaldehyde into small carbon units which combines to form sugar and free radicals. These free radical formation is slow process but these free radicals are only responsible for the unusual behaviour by a drunk person, and hence it is calculated a normal person can handle 5 glasses of alcohol in an hour. Since aldehyde breakdown is slow proc...