Properties of Water and Introduction to Macromolecules

Water is polar, which means it forms hydrogen bonds that allow ions and polar molecules to dissolve easily. This makes water an excellent solvent for life processes. Water's hydrogen bonds give it a high heat capacity—when temperature rises, these bonds break and reform, keeping overall temperature stable. This is why your body temperature doesn't fluctuate wildly!

Water molecules are both cohesive (stick to each other) and adhesive (stick to other surfaces). Cohesion creates surface tension, which is why water bugs can walk on water. Adhesion allows water to rise inside narrow spaces through capillary action, helping plants transport water upward.

Carbon is another crucial element for life. It forms four covalent bonds with other atoms like oxygen, hydrogen, and nitrogen, creating the backbone of all biological molecules.

Quick Fact: A single drop of water contains more molecules than there are stars in our galaxy! Yet each water molecule follows the same simple rules of chemistry.

Biological macromolecules include proteins, carbohydrates, nucleic acids, and lipids. These large molecules are made of smaller units called monomers that join together through covalent bonds to form polymers. When monomers connect, they release a water molecule through a process called dehydration synthesis. Breaking these bonds requires adding water back in a process called hydrolysis.

Carbohydrates are vital energy sources for cells and provide structural support in plants, fungi, and arthropods. They're classified based on the number of monomers they contain—monosaccharides (single units), disaccharides (two units), or polysaccharides (many units).