Chapter 2: Inorganic and Organic Compounds (Lecture Notes)

Vocabulary flashcards covering the key terms, definitions, and examples from the lecture notes on inorganic/organic compounds and the four major organic biomolecule groups (carbohydrates, proteins, lipids, nucleic acids).

Inorganic compounds

Compounds that generally lack carbon; small, simple molecules such as H2O, O2, salts, acids & bases.

Organic compounds

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

Carbon skeleton

A chain or backbone of carbon atoms that forms the main structure of an organic molecule.

Functional groups

Groups of atoms that bind to the carbon skeleton and determine the properties and reactions of the molecule.

Dehydration synthesis

Process of building up larger molecules (polymers) from smaller monomers by removing a water molecule.

Hydrolysis

Process of breaking down polymers into monomers by adding water and breaking covalent bonds.

Covalent bonds

Bonds formed by the sharing of electrons between atoms; strong chemical bonds.

Carbohydrates

Major organic compounds made of carbon, hydrogen, and oxygen; quick energy sources and, in some cases, structural components.

Monosaccharides

Simple sugars (3–7 carbon atoms) that are sweet and water-soluble; glucose, fructose, and deoxyribose are examples.

Disaccharides

Carbohydrates formed when two monosaccharides link via a glycosidic bond during dehydration synthesis; examples include sucrose and lactose.

Polysaccharides

Long chains of many monosaccharides; function as long-term energy storage or structural components (e.g., starch, glycogen, cellulose).

Glucose

A monosaccharide that provides quick energy for living cells; a key example of a carbohydrate.

Fructose

A monosaccharide found in fruits; a simple sugar isomer of glucose.

Deoxyribose

5-carbon sugar in DNA; component of the DNA backbone.

Sucrose

Disaccharide composed of glucose and fructose; common table sugar.

Lactose

Disaccharide composed of glucose and galactose; milk sugar.

Starch

Polysaccharide in plants that serves as a long-term energy store.

Glycogen

Polysaccharide in animals that serves as a highly branched energy storage molecule.

Cellulose

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

Proteins

Large biomolecules made of amino acids; essential for structure and function; diverse in form and role.

Amino acids

Building blocks of proteins; 20 different kinds; central carbon with amino group, carboxyl group, hydrogen, and an R group.

Peptide bonds

Covalent bonds that link amino acids together during dehydration synthesis.

Amino group

NH2 group found at one end of amino acids.

Carboxyl group

COOH group found at one end of amino acids.

R group

Variable side chain attached to the central carbon of an amino acid; determines identity and properties.

Denaturation

Loss of protein structure (and thus function) due to extreme conditions like high temperature or low pH.

Primary structure

Protein level: linear sequence of amino acids in a polypeptide.

Secondary structure

Protein level: folding into local structures like alpha helices or beta pleated sheets stabilized by hydrogen bonds.

Tertiary structure

Protein level: overall 3D folding due to interactions among R groups (disulfide bridges, hydrogen bonds, ionic bonds).

Quaternary structure

Protein level: two or more polypeptide chains assemble into a functional unit (e.g., hemoglobin, antibodies).

Keratin

Structural protein that reinforces skin and provides a barrier to infection.

Channel proteins

Membrane proteins that form channels or carriers to transport substances across cell membranes.

Enzymes

Proteins that accelerate chemical reactions; highly specific in function.

Antibodies

Proteins of the immune system that recognize and help neutralize foreign invaders.

Bacterial toxins

Poisonous proteins produced by some bacteria.

Sulfur-containing amino acids

AAs that contain sulfur; there are two: cysteine and methionine.

Lipids

Macromolecules composed mainly of carbon, hydrogen, and oxygen; not soluble in water; include triglycerides, phospholipids, steroids, and waxes.

Triglycerides

Glycerol molecule bonded to three fatty acids via ester bonds; primary energy storage molecules.

Ester bond

Bond formed between glycerol and fatty acids in triglycerides.

Saturated fatty acids

Fatty acids with no double bonds between carbon atoms; typically solid at room temperature.

Unsaturated fatty acids

Fatty acids with one or more double bonds; typically liquid at room temperature.

Phospholipids

Complex lipids with glycerol, two fatty acids, and a phosphate group; form the phospholipid bilayer of cell membranes; have polar heads and nonpolar tails.

Waxes

Hydrophobic lipids that provide protection and waterproofing in nature.

Glycolipids

Lipids with carbohydrate chains attached; involved in cell recognition and signaling.

Mycolic acid

Wax-like lipid found in the cell wall of Mycobacterium species (e.g., M. tuberculosis).

Steroids and Sterols

Lipids with four fused carbon rings; include OH-bearing sterols; function as membrane components and signaling molecules.

Cholesterol

A sterol found in animal cell membranes; important for membrane fluidity and as a precursor to steroid hormones.

Phytosterol

Sterol found in plant cell membranes; similar function to cholesterol in plants.

Ergosterol

Sterol found in fungal cell membranes.

Nucleic acids

Biomolecules that store and transmit genetic information; DNA and RNA; built from nucleotides.

Nucleotides

Subunits of nucleic acids; consist of a sugar, a phosphate group, and a nitrogenous base.

Phosphodiester bond

Covalent bond linking nucleotides in nucleic acids via dehydration synthesis.

Sugar (pentose)

Five-carbon sugar part of a nucleotide; deoxyribose in DNA and ribose in RNA.

Phosphate group

Phosphate moiety attached to the sugar in a nucleotide.

Nitrogenous bases

Bases in nucleotides; Purines (adenine, guanine) and Pyrimidines (cytosine, thymine, uracil).

Purines

Family of nitrogenous bases: adenine and guanine.

Adenine

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

Guanine

Purine base that pairs with cytosine in both DNA and RNA.

Pyrimidines

Family of nitrogenous bases: cytosine, thymine, and uracil.

Cytosine

Pyrimidine base that pairs with guanine.

Uracil

Pyrimidine base found in RNA; replaces thymine.

Thymine

Pyrimidine base found in DNA; pairs with adenine.

DNA

Deoxyribonucleic acid; double-stranded helical molecule with a sugar-phosphate backbone; A–T and C–G base pairs; thymine present.

RNA

Ribonucleic acid; typically single-stranded; contains uracil instead of thymine; three main types: mRNA, tRNA, rRNA; involved in protein synthesis.

mRNA

Messenger RNA; carries genetic information from DNA to ribosomes for protein synthesis.

tRNA

Transfer RNA; brings amino acids to ribosomes during protein synthesis.

rRNA

Ribosomal RNA; structural and catalytic component of ribosomes.

ATP

Adenosine Triphosphate; nucleotide with three phosphate groups; high-energy molecule that releases energy upon hydrolysis.

A-T base pairing

Adenine pairs with thymine in DNA via hydrogen bonds.

C-G base pairing

Cytosine pairs with guanine in DNA via hydrogen bonds.