Carbon: the Three Main Forms of the Element

Introduction
Carbon is important in biology because carbon forms the "back-bone" of just about all biologically important molecules. This is because carbon forms long and sometimes complex covalently bonded structures and also because carbon compounds vary greatly in the type of interactions they have with water. For example some carbon compounds, such as most lipids, have strictly hydrophobic interactions with water, others such as sugars are hydrophilic. Still others such as proteins and phospholipids are partly hydrophobic and partly hydrophilic.

Diamond VBS Home page,VBS Course Navigator, Basic Chemistry, Biochemical Gallery, Previous Page, Next Page,top of page . Diamonds form deep in the earth under extreme pressure and heat. A diamond is essentially one large covalently bonded molecule as shown here. Previous Page

Graphite VBS Home page,VBS Course Navigator, Basic Chemistry, Biochemical Gallery, Previous Page, Next Page,top of page The "lead" in pencils is actually largely the second form of carbon, which is called graphite. Graphite is soft but consists of many small flat crystals consisting of covalently bonded carbon molecules. Its the sliding of these crystals past each other that makes graphite soft and slippery. Previous Page

Fullerine VBS Home page,VBS Course Navigator, Basic Chemistry, Biochemical Gallery, Previous Page, Next Page,top of page Imagine scientist's surprise when they found this form of carbon in soot! Fullerine gets its name because it resembles the geodesic domes developed by Buckminster Fuller. More informally these shapes are called "Bucky balls". Fullerine also occurs in large balls and tubular fullerine structures have been made in the laboratory.