Carbon atoms usually have a Lewis electron configuration of 2.4. To gain a stable electron configuration of 2.8, they usually form covalent bonds with other atoms such as another carbon and hydrogen. Carbon does not form ionic bonds because it would require much more energy for the atom to gain 4 electrons or lose the 4 electrons to achieve electron configuration. This is why carbon is a significant atom of life due to its versatility in how it bonds with other atoms including other carbon atoms. It can also form single double and triple bonds giving rise to many compounds, with the same elements, but with different properties.
The small intestine absorbs most digested food molecules, as well as water and minerals, and passes them on to other parts of the body for storage or further chemical change.