Chapter 2: Inorganic and Organic Compounds (Notes)

Vocabulary-style flashcards covering key concepts from Chapter 2 notes on inorganic/organic compounds, biomolecules, and their structures and functions.

Inorganic compounds

Small, simple molecules that usually lack carbon; examples include H2O, O2, salts, acids & bases.

Organic compounds

Large, structurally complex molecules that always contain carbon and are held together by covalent bonds.

Carbon skeleton

The chain or framework of carbon atoms that forms the backbone of many organic molecules.

Functional groups

Groups of atoms attached to the carbon skeleton that determine the properties and reactivity of organic compounds.

Dehydration synthesis

Process of building larger molecules by removing water; monomers join to form polymers, creating covalent bonds.

Hydrolysis

Process of breaking down polymers by adding water; polymers are split into monomers by breaking covalent bonds.

Monomer

A small molecule that can join with others to form a polymer.

Polymer

A large molecule made by linking many monomers together.

Covalent bonds

Bonds formed by sharing electron pairs between atoms, holding monomers together in polymers.

Four most common elements in organic compounds

Carbon, Hydrogen, Oxygen, and Nitrogen.

Carbon

A primary element in organic compounds; forms the carbon skeleton of molecules.

Hydrogen

A primary element in organic compounds; often bonded to carbon and oxygen.

Oxygen

A primary element in organic compounds; part of many functional groups and biomolecules.

Nitrogen

A primary element in organic compounds; essential in amino acids and nucleic acids.

Carbohydrates

Organic compounds made of carbon, hydrogen, and oxygen; usually end in -ose and provide energy or structural support.

Proteins

Organic compounds composed of C, H, O, N (and sometimes S); essential for structure, function, and regulation in organisms.

Lipids

Hydrophobic organic molecules composed mainly of C, H, and O; key components of cell membranes and energy storage.

Nucleic acids

Polymers of nucleotides (DNA and RNA) that store and transmit genetic information.

Amino acids

Building blocks of proteins; 20 different AAs with an amino group, a carboxyl group, a hydrogen, and a variable R group attached to a central carbon.

Peptide bond

Covalent bond formed by dehydration synthesis between the amino group of one amino acid and the carboxyl group of another.

Protein structure

The three- to four-level arrangement of a protein (Primary, Secondary, Tertiary, Quaternary) that determines its function.

Primary structure

The linear sequence of amino acids in a polypeptide.

Secondary structure

Regular folding patterns such as alpha helices and beta sheets stabilized by hydrogen bonds.

Tertiary structure

Overall 3D shape of a protein due to interactions among R groups (disulfide, hydrogen, ionic bonds).

Quaternary structure

Association of two or more polypeptide subunits into a functional protein complex.

Denaturation

Loss of a protein’s structure and function due to factors like high temperature or extreme pH.

Keratin

Structural protein that reinforces skin and provides a protective barrier.

Protein channels

Membrane proteins that form pores to facilitate transport across cell membranes.

Enzymes

Protein catalysts that speed up chemical reactions.

Antibodies

Proteins involved in immune defense that recognize and neutralize pathogens.

Bacterial toxins

Toxic proteins produced by certain bacteria.

Nucleotides

Building blocks of nucleic acids consisting of a sugar, a phosphate group, and a nitrogenous base.

Purines

Nitrogenous bases that are double-ring structures (Adenine and Guanine).

Adenine

Purine base found in DNA and RNA.

Guanine

Purine base found in DNA and RNA.

Pyrimidines

Nitrogenous bases that are single-ring structures (Cytosine, Uracil, Thymine).

Cytosine

Pyrimidine base found in DNA and RNA.

Uracil

Pyrimidine base found in RNA (replaces thymine).

Thymine

Pyrimidine base found in DNA (replaced by uracil in RNA).

DNA

Deoxyribonucleic acid; double-stranded molecule with a sugar–phosphate backbone and A–T, C–G base pairing.

RNA

Ribonucleic acid; usually single-stranded; contains uracil instead of thymine and uses ribose sugar.

Adenosine triphosphate (ATP)

High-energy nucleotide that stores and provides energy through hydrolysis of phosphate bonds.

Phosphodiester bond

Covalent bond joining nucleotides in nucleic acids via the phosphate group linking sugars.

Sugar (pentose)

Five-carbon sugar component of nucleotides (deoxyribose in DNA; ribose in RNA).

Deoxyribose

Five-carbon sugar in DNA; lacks an oxygen atom at the 2' position.

A–T and C–G pairing

Hydrogen-bonded base pairs in DNA: Adenine with Thymine; Cytosine with Guanine.

Glycosidic bond

Bond joining monosaccharides to form disaccharides through dehydration synthesis.

Monosaccharides

Simple sugars with 3–7 carbon atoms (e.g., glucose, fructose, deoxyribose).

Disaccharides

Carbohydrates formed by two monosaccharides linked by a glycosidic bond (e.g., sucrose, lactose).

Polysaccharides

Polymers of many monosaccharides; include starch, glycogen, and cellulose.

Glucose

A monosaccharide; main quick energy source for living cells.

Fructose

A monosaccharide sugar found in fruits; isomer of glucose.

Starch

Polysaccharide in plants; major long-term energy storage.

Glycogen

Polysaccharide in animals; major long-term energy storage molecule.

Cellulose

Polysaccharide that provides structural support in plant cell walls; polymer of glucose.

Lipids

Group of hydrophobic biomolecules including fats, phospholipids, steroids, and waxes.

Triglycerides

Simple lipids made of glycerol and three fatty acids; main form of stored energy.

Ester bond

Bond formed between glycerol and fatty acids in triglycerides via dehydration synthesis.

Saturated fats

Fats with no double bonds in fatty acids; typically solid at room temperature.

Unsaturated fats

Fats with one or more double bonds in fatty acids; typically liquid at room temperature.

Phospholipids

Complex lipids with glycerol, two fatty acids, and a phosphate group; form cell membranes.

Phospholipid bilayer

Two-layer structure of phospholipids that forms the basic architecture of cell membranes.

Polar head

Hydrophilic region of a phospholipid that faces aqueous environments.

Nonpolar tails

Hydrophobic region of a phospholipid made of fatty acids.

Waxes

A type of lipid with long chains; waterproofing and protection roles in organisms.

Glycolipids

Lipids with carbohydrate groups attached; important in membrane structure and signaling.

Mycolic acid

Waxy lipid component found in the cell walls of Mycobacterium species.

Steroids and sterols

Lipids with a multi-ring structure; sterols have an -OH group and are components of membranes.

Cholesterol

Sterol essential for eukaryotic cell membrane structure and function.

Phytosterol

Sterol found in plant cell membranes.

Ergosterol

Sterol found in fungal cell membranes.