Sugar molecules are held together by covalent bonds. These are strong bonds formed by the sharing of electrons between atoms. In the case of sugar, the atoms involved are primarily carbon (C), hydrogen (H), and oxygen (O).

Here's a breakdown of how it works:

* Carbon's Bonding Capacity: Carbon has four electrons in its outer shell and needs eight to be stable. It forms four covalent bonds with other atoms.

* Hydrogen's Bonding Capacity: Hydrogen has one electron in its outer shell and needs two to be stable. It forms one covalent bond.

* Oxygen's Bonding Capacity: Oxygen has six electrons in its outer shell and needs eight to be stable. It forms two covalent bonds.

These atoms combine in specific arrangements to form the sugar molecules. For example, in glucose, a common sugar, the atoms are linked in a chain with the following structure: C6H12O6.

The specific arrangement of these bonds determines the shape and properties of the sugar molecule.