Water Chemistry & Biological Macromolecules Overview

What is the chemical formula for water?

H₂O

What type of bonds do water molecules form with each other?

Hydrogen bonds (H-bonds)

Why is water known as the universal solvent?

Because its polarity allows it to dissolve many substances.

What are the major properties of water?

Cohesion & adhesion, good solvent, lower density as a solid, high specific heat, high heat of vaporization.

Define cohesion in the context of water.

The hydrogen bonding between water molecules.

Define adhesion in the context of water.

The hydrogen bonding between water molecules and other substances.

What phenomenon allows water to climb up a paper towel?

Capillary action due to adhesion.

What is transpiration in plants based on water's properties?

The process of water movement through a plant and its evaporation from aerial parts.

What happens to water when it ionizes?

It splits into H⁺ and OH⁻ ions.

What indicates a neutral pH in water?

[H+] = [OH-]

What is the role of buffers in biological systems?

They help maintain a stable pH by absorbing or donating H+ ions.

Why does ice float on water?

Because hydrogen bonds form a crystal structure in ice, making it less dense than liquid water.

What is high specific heat in water?

Water resists changes in temperature, requiring a lot of energy to heat up or cool down.

What is the significance of high heat of vaporization in organisms?

It allows organisms to cool down through processes like sweating.

What are the four classes of biological macromolecules?

Carbohydrates, lipids, proteins, and nucleic acids.

What is the monomer of carbohydrates?

Monosaccharides.

What is the function of carbohydrates in cells?

They provide short-term energy and dietary fiber.

How can simple sugars be identified?

Using Benedict's Solution, which turns red-yellow.

What is the monomer of lipids?

Fatty acids and glycerol.

What is the function of lipids in cells?

They provide long-term energy and make up cell membranes.

What is the monomer of proteins?

Amino acids.

What is the function of proteins in cells?

They provide structure, send chemical signals, and speed up reactions.

How can proteins be identified?

Using Biuret's Reagent, which turns purple-violet.

What is the monomer of nucleic acids?

Nucleotides.

What is the function of nucleic acids?

They store and pass on genetic information.