Biology Molecule Definitions Flashcards

Molecule and Related Definitions

• Molecules are the smallest units of chemical compounds, consisting of more than one atom.
• Covalent bonds occur when atoms share pairs of electrons, forming a strong connection.
• Polar molecules have covalent bonds and exhibit partial positive and negative charges, leading to unique properties.
• Mixtures consist of two or more substances that are physically combined but not chemically bonded.
• Solutions are homogeneous mixtures of two or more substances, where one component is typically a liquid, often referred to as a solvent.
• Solvents are liquids that dissolve solutes to create solutions, essential in various chemical processes.
• Solutes are the solids or substances that dissolve in a solvent to form a solution.

Properties of Molecules

• Cohesion refers to the attraction between identical molecules, aiding in the formation of liquid droplets and surface tension.
• Adhesion describes the attraction between different types of molecules, important for processes like capillary action.
• Heat capacity measures the amount of heat required to raise a substance's temperature, influencing temperature regulation in biological systems.

Acid-Base Chemistry

• The pH scale indicates a solution's acidity, with lower values signifying higher acidity levels.
• Acids are compounds that release hydrogen ions (H⁺) when dissolved in water, affecting pH levels.
• Bases produce hydroxide ions (OH⁻) in solutions, contributing to alkalinity.