Chemistry Review: Chapter 2 — Chemical Reactions, Water, and Organic vs Inorganic Compounds

A comprehensive set of vocabulary flashcards covering key terms from chemical reactions, enzymes, water chemistry, and inorganic vs. organic compounds as presented in the notes.

Reactant

A substance that participates in a chemical reaction; the starting materials.

Product

The substance produced at the end of a chemical reaction.

Synthesis reaction

A + B -> AB; anabolic process that builds a larger molecule and often stores energy in bonds.

Anabolic

Metabolic processes that build larger molecules from smaller ones.

Decomposition reaction

AB -> A + B; catabolic process that breaks down a molecule into smaller parts.

Catabolic

Metabolic processes that break down molecules into smaller pieces.

Exchange reaction

Bonds are broken and re-formed, exchanging partners to form new products.

Activation energy

The threshold energy required to start a chemical reaction.

Enzyme

A protein that acts as a biological catalyst, lowering activation energy and increasing reaction rate.

Catalyst

A substance that increases the rate of a chemical reaction; enzymes are biological catalysts.

Dehydration synthesis

Two monomers covalently bonded with the release of a water molecule to form a polymer.

Hydrolysis

A reaction that breaks a bond by adding water, producing two monomers.

Salt

A compound that dissociates into ions in water.

Electrolyte

Ions in solution that conduct electricity; produced by dissociation of salts.

Acid

A substance that dissociates in water to release hydrogen ions (H+).

Base

A substance that releases hydroxide ions (OH-) or accepts H+ to reduce acidity.

Buffer

A solution that resists pH changes by neutralizing added acids or bases.

pH

A scale (0–14) measuring acidity/basicity; 7 is neutral.

Inorganic compound

Compounds that do not rely on carbon-hydrogen bonds for their primary structure.

Organic compound

Compounds that contain both carbon and hydrogen (may also include other elements).

Carbohydrate

Organic molecules with C, H, and O in roughly CH2O; includes sugars and starches.

Monosaccharide

The simplest sugars; monomers of carbohydrates (e.g., glucose, fructose, galactose, ribose, deoxyribose).

Disaccharide

Two monosaccharides joined together (e.g., sucrose, lactose, maltose).

Polysaccharide

Many monosaccharide units; starch, glycogen, cellulose are examples.

Glucose

A hexose monosaccharide; primary energy source for cells.

Fructose

A hexose sugar found in fruits; is an isomer of glucose.

Galactose

A hexose sugar that is a component of lactose.

Hexose

A six-carbon monosaccharide (e.g., glucose, fructose, galactose).

Pentose

A five-carbon sugar (e.g., ribose, deoxyribose).

Glycogen

Storage form of glucose in liver and muscle tissue.

Starch

Storage polysaccharide in plants; polymer of glucose.

Cellulose

Structural polysaccharide in plant cell walls; not digestible by humans.

Lipid

Hydrophobic, nonpolar group of compounds rich in hydrocarbons; includes triglycerides, phospholipids, steroids, prostaglandins.

Triglyceride

Glycerol plus three fatty acids; major dietary lipid and energy reserve in adipose tissue.

Glycerol

Backbone molecule of triglycerides to which fatty acids attach.

Fatty acid

Hydrocarbon chain with a carboxyl group; three attach to a triglyceride.

Phospholipid

Lipid with glycerol backbone, two fatty acids, and a phosphate head; forms cell membranes.

Steroid

Lipid with four fused hydrocarbon rings; cholesterol is a key example.

Prostaglandin

Lipid-derived signaling molecule involved in inflammation, blood pressure, and pain.

Protein

Polymers of amino acids; structure determines function; can be enzymes.

Amino acid

Monomer of proteins; contains amino group, carboxyl group, central carbon, and variable side chain (R).

Peptide bond

Covalent bond linking amino acids in a protein.

Polypeptide

Long chain of amino acids; can fold into a functional protein.

Denaturation

Unfolding or loss of protein structure and function due to heat or other stress.

Active site

Region of an enzyme where the substrate binds to form a product.

Substrate

Reactant that binds to an enzyme at its active site.

Enzyme-substrate complex

Transient complex formed when a substrate binds to an enzyme during catalysis.

Nucleotide

Subunit of nucleic acids consisting of a phosphate group(s), a pentose sugar, and a nitrogenous base.

Nucleic acid

DNA or RNA; polymers of nucleotides involved in storing and transmitting genetic information.

DNA

Deoxyribonucleic acid; stores genetic information; contains deoxyribose, a phosphate group, and bases A, C, G, T; usually a double helix.

RNA

Ribonucleic acid; helps manifest genetic code and protein synthesis; contains ribose, a phosphate group, and bases A, C, G, U.

Adenine

Purine base; pairs with thymine in DNA and with uracil in RNA.

Cytosine

Pyrimidine base; pairs with guanine in both DNA and RNA.

Guanine

Purine base; pairs with cytosine in DNA and RNA.

Thymine

Pyrimidine base; pairs with adenine in DNA (not in RNA).

Uracil

Pyrimidine base; replaces thymine in RNA, pairs with adenine.

ATP

Adenosine triphosphate; energy currency of the cell; consists of ribose, adenine, and three phosphates with high-energy bonds.

Deoxyribose

Five-carbon sugar in DNA.

Ribose

Five-carbon sugar in RNA.

Phosphate group

Phosphate moiety in nucleotides; part of ATP and nucleic acids.

Hydrogen bond

Weak bond between complementary bases (A-T with 2 H-bonds, G-C with 3 H-bonds) stabilizing DNA structure.

Universal solvent

Water's role as the most versatile solvent in which most substances dissolve.

Heat sink

Substance (like water) that absorbs heat without a large temperature rise, helping regulate temperature.

Hydrophobic

Water-fearing; nonpolar substances that do not mix well with water.

Hydrophilic

Water-loving; polar substances that dissolve well in water.