Organic Compounds: Carbohydrates & Lipids

Comprehensive vocabulary flashcards covering organic chemistry principles, functional groups, macromolecule synthesis and breakdown, carbohydrates, proteins, nucleic acids, and lipids.

Organic molecule

In chemistry, a molecule that contains $C\text{-}H$ bonds.

Methane

The simplest organic molecule, consisting of a single carbon atom covalently bonded to four hydrogen atoms ($CH_4$).

Four categories of organic molecules

The four main classes of biological macromolecules: carbohydrates, proteins, lipids, and nucleic acids.

Carbon bonding properties

Carbon forms $4$ covalent bonds, readily bonds with other carbon atoms to form long chains and rings, and readily bonds with other atoms including hydrogen, oxygen, nitrogen, and sulfur.

Carbon backbone

A foundational structure in biological molecules consisting of long chains of carbon and hydrogen atoms, also referred to as a hydrocarbon chain.

Nonpolar covalent bond

A bond formed between atoms with an electronegativity difference around $0.4$ or less, such as the $C\text{-}H$ bond ($2.5 - 2.1 = 0.4$).

Functional group

Clusters of specific atoms attached to a carbon backbone that determine properties such as polarity, hydrogen bonding, and acidity or basicity, consistently exhibiting the same properties regardless of the molecule attached.

R group

A placeholder symbol representing any generic organic group of atoms, usually consisting of carbon and hydrogen, attached to the rest of a molecule.

Hydroxyl group

A polar and hydrophilic (water-loving) functional group with the formula $-OH$, commonly found in sugars.

Carbonyl group

A polar functional group with the formula $-CO$, commonly occurring in sugars.

Carboxyl group

A polar functional group with the formula $-COOH$ that occurs in sugars, amino acids, and proteins, acting as an acid ($H^+$ donor).

Amino group

A polar functional group with the formula $-NH_2$ that occurs in amino acids and proteins, acting as a base by accepting/bonding $H^+$.

Sulfhydryl group

A weakly polar functional group with the formula $-SH$ occurring in amino acids and proteins, capable of interacting with another $-SH$ group to form a covalent bond.

Phosphate group

A polar functional group with the formula $-H_2PO_4$ occurring in nucleic acids and ATP that acts as an acid ($H^+$ donor).

Methyl group

A nonpolar and hydrophobic (water-fearing) functional group with the formula $-CH_3$, found in lipids and amino acids.

Macromolecule

Gigantic organic molecules with high molecular weights, most of which are constructed as polymers.

Polymer

A molecule made of a repeating series of identical or similar subunits called monomers.

Monomer

A single repeating subunit that can bond with others to form a polymer.

Polymerization

The chemical process of joining monomers together to form a polymer.

Dehydration synthesis

A type of synthesis reaction where monomers are covalently linked by removing an $OH^-$ and an $H^+$ from the monomers to produce water ($H_2O$) as a product.

Hydrolysis

A type of decomposition reaction in which an enzyme breaks the covalent bond between monomers using water ($H_2O$ autoionized into $OH^-$ and $H^+$) as a reactant.

Protein

A large organic polymer made of chains of amino acid monomers that serves structural, regulatory, protective, transport, and enzymatic functions.

Amino acid

The fundamental building block of proteins, structured around a central carbon bonded to an amino group, a hydrogen atom, a carboxyl group, and a variable side chain (R-group).

DNA

Deoxyribonucleic Acid; a nucleic acid consisting of a large polynucleotide containing millions of nucleotide monomers arranged in a double helix.

Nucleotide

The monomer subunit of DNA and nucleic acids, composed of a phosphate group, a deoxyribose sugar, and a nitrogenous base.

Pyrimidines

Single-ringed nitrogenous bases found in DNA, specifically Cytosine (C) and Thymine (T).

Purines

Double-ringed nitrogenous bases found in DNA, specifically Guanine (G) and Adenine (A).

Carbohydrate

A large group of organic molecules with the general formula $(CH_2O)_n$ exhibiting a $1:2:1$ ratio of carbon to hydrogen to oxygen, which includes sugars and starch.

Monosaccharide

The simplest carbohydrate and sugar monomer, typically ending in the suffix '-ose', including glucose, galactose, and fructose.

Isomers

Compounds that have the same molecular formula (such as $C_6H_{12}O_6$ for glucose, galactose, and fructose) but a different arrangement of atoms.

Disaccharide

A sugar molecule formed by joining two monosaccharides together through dehydration synthesis.

Sucrose

Table sugar; a disaccharide formed by bonding Glucose and Fructose.

Lactose

Milk sugar; a disaccharide formed by bonding Glucose and Galactose.

Maltose

A disaccharide found in grain products formed by bonding two Glucose molecules together.

Oligosaccharides

Medium-sized carbohydrate chains composed of approximately $3$ to $10$ monosaccharides.

Maltotriose

A trisaccharide consisting of three glucose molecules produced by the breakdown of starch.

Raffinose

A trisaccharide composed of galactose, glucose, and fructose that is found in many plants.

Polysaccharide

Long chains of monosaccharides bonded together through dehydration synthesis.

Amylose

Dietary starch; a polysaccharide composed of glucose monomers that serves as the energy storage molecule of plants.

Cellulose

Dietary fiber; an insoluble polysaccharide composed of glucose monomers that serves as a structural molecule in plants.

Glycogen

A branched polysaccharide composed of glucose monomers that acts as the primary energy storage molecule of animals.

Lipids

A group of hydrophobic, nonpolar organic molecules consisting of carbon, hydrogen, and oxygen that are not built from repeating monomer subunits, including fats, oils, waxes, and cholesterol.

Four primary types of lipids

The major classes of lipid molecules: fatty acids, triglycerides, phospholipids, and steroids.

Fatty acid

A lipid molecule consisting of a long hydrocarbon ($C\text{-}H$) chain with a carboxyl group on one end and a methyl group on the other end.

Saturated fatty acid

A straight fatty acid molecule in which all carbon atoms are linked by single covalent bonds, holding the maximum possible number of hydrogen atoms.

Unsaturated fatty acid

A bent or kinked fatty acid molecule containing one or more double bonds between carbon atoms with the potential to add hydrogen atoms.

Palmitic acid

The most common saturated fatty acid found in the human body ($\text{CH}_3(\text{CH}_2)_{14}\text{COOH}$).

Stearic acid

A long-chain saturated fatty acid occurring in natural sources including shea butter and coconut oil ($\text{CH}_3(\text{CH}_2)_{16}\text{COOH}$).

Linoleic acid

A polyunsaturated fatty acid that contains two carbon-carbon double bonds.

Triglyceride

A lipid molecule consisting of a glycerol head attached to three fatty acid tails.

Phospholipid

A lipid consisting of a hydrophilic head and two hydrophobic fatty acid tails, essential for cell membranes.

Cholesterol

A steroid lipid characterized by a four-ring carbon skeleton with an attached hydrocarbon tail and polar group.