chemistry of life chapter

Matter

Anything that has mass and occupies space.

Atoms

The smallest units that retain the properties of an element.

Protons

Positively charged particles that determine the element’s identity.

Neutrons

Neutral particles that add mass and influence stability.

Electrons

Negatively charged particles that determine chemical behavior.

Atomic Number

The number of protons in an atom.

Mass Number

The sum of protons and neutrons in an atom.

Isotopes

Atoms of the same element with different mass due to varying neutrons.

Ions

Charged particles that form when atoms gain or lose electrons.

Cations

Positively charged ions formed by losing electrons.

Anions

Negatively charged ions formed by gaining electrons.

Chemical Bonds

Forces that hold atoms together in a molecule.

Ionic Bonds

Bonds formed between cations and anions through electron transfer.

Covalent Bonds

Bonds formed when atoms share electrons.

Nonpolar Covalent Bonds

Bonds where electrons are shared equally.

Polar Covalent Bonds

Bonds where electrons are shared unequally, resulting in partial charges.

Molecule

Two or more atoms bonded together.

Compound

A molecule consisting of different elements.

Hydrogen Bonds

Weak bonds that form due to the polarity of water.

Cohesion

The ability of water molecules to stick to each other.

Adhesion

The ability of water to stick to other surfaces.

pH

A measure of hydrogen ion concentration in a solution.

Acids

Substances that donate hydrogen ions (H⁺).

Bases

Substances that accept hydrogen ions (H⁺).

Buffers

Substances that help maintain pH stability in biological systems.

Hydration Shells

Layers of water molecules surrounding solutes.

High Specific Heat

The ability of water to absorb a lot of heat before temperature rises.

High Heat of Vaporization

The amount of energy required to convert water into vapor.

Colloid

A mixture with medium-sized particles that remain suspended.

Suspension

A mixture with large particles that settle if left still.

Hydrolysis

A chemical reaction where water breaks bonds, typically in digestion.

Dehydration Synthesis

A reaction where water is removed to form new bonds.

Chemical Energy

Stored energy in chemical bonds of molecules.

First Law of Thermodynamics

Energy cannot be created or destroyed, only converted from one form to another.

Second Law of Thermodynamics

Every energy conversion releases heat, making it unusable energy.

Decomposition Reaction

A reaction where large molecules break down into smaller ones, releasing energy.

Synthesis Reaction

A reaction where smaller molecules combine to form larger ones, requiring energy.

Exchange Reactions

Reactions where bonds are broken and formed, swapping atoms between molecules.

Oxidation

The loss of electrons during a chemical reaction.

Reduction

The gain of electrons during a chemical reaction.

Activation Energy

The minimum energy required to start a reaction.

Enzymes

Biological catalysts that lower activation energy and increase reaction speed.

ATP

Adenosine triphosphate, the energy currency of the cell.

Polymers

Large molecules made from repeating monomers.

Monomers

Small building blocks that join to form polymers.

Functional Groups

Specific groups of atoms that influence the behavior of organic compounds.

Carbohydrates

Organic molecules made of C, H, O, primarily for energy.

Lipids

Hydrophobic organic molecules involved in long-term energy storage and cell membrane structure.

Proteins

Polymers formed from amino acids that perform various functions in the body.

Nucleic Acids

Biomolecules, DNA and RNA, that store and transmit genetic information.

Why Carbon Is Essential

Carbon’s ability to form four covalent bonds allows for complex structures.

Biological Importance of Organic Compounds

Essential for energy production, cell structure, genetic inheritance, and enzyme activity.