bio study set 1

Organic Chemistry

The study of carbon compounds, ranging from simple molecules like methane ($CH_4$) to colossal ones like proteins and nucleic acids.

Biochemistry

The study of chemical reactions occurring in living beings.

Vitalism

The concept that organic compounds arise only within living organisms, which was disproved when chemists synthesized organic compounds in the laboratory.

Stanley Miller's 1953 Experiment

An experiment that simulated primordial Earth conditions using electrical discharges in a primitive atmosphere of $H_2O$, $H_2$, $NH_3$, and $CH_4$ to demonstrate that organic compounds could be synthesized abiotically.

Tetravalence of Carbon

The property of carbon having four valence electrons in a shell that holds eight, allowing it to form four covalent bonds with a variety of atoms.

Hydrocarbons

Molecules consisting strictly of carbon and hydrogen atoms, which are found in many of a cell's organic molecules.

Isomers

Molecules that share the exact same molecular formula but have different structures and properties.

Structural Isomers

Isomers that differ in the covalent arrangement of their atoms, such as pentane and 2-methyl butane.

Geometric Isomers

Isomers that have the same covalent partnerships but differ in spatial arrangement around a double bond, classified as cis (same side) or trans (opposite sides).

Enantiomers

Isomers that are non-superimposable mirror images of each other, such as L-Dopa (biologically active in treating Parkinson's disease) and D-Dopa (biologically inactive).

Functional Groups

Chemically reactive groups of atoms within an organic molecule that give the molecule its distinctive chemical properties.

Hydroxyl Group

A functional group consisting of a hydrogen atom bonded to an oxygen atom ($-OH$), forming polar alcohols that can form hydrogen bonds with water.

Carbonyl Group

A functional group consisting of a carbon atom double-bonded to an oxygen atom ($>C=O$), forming ketones when inside a carbon skeleton or aldehydes when at the end.

Carboxyl Group

A functional group featuring a carbon atom double-bonded to an oxygen atom and single-bonded to a hydroxyl group ($-COOH$), which exhibits acidic properties by donating an $H^+$ ion.

Amino Group

A functional group consisting of a nitrogen atom bonded to two hydrogen atoms ($-NH_2$), which acts as a base by accepting an $H^+$ ion and carrying a $1+$ charge under cellular conditions.

Sulfhydryl Group

A functional group consisting of a sulfur atom bonded to a hydrogen atom ($-SH$), found in thiols such as cysteine, which can form covalent cross-links to stabilize protein structure.

Phosphate Group

A functional group consisting of a phosphorus atom bonded to four oxygen atoms ($-OPO_3^{2-}$), contributing a negative charge ($2-$ at the end, $1-$ internally) and releasing energy upon reacting with water.

Methyl Group

A functional group consisting of a carbon atom bonded to three hydrogen atoms ($-CH_3$), which affects gene expression when added to DNA or molecules bound to DNA.

Macromolecules

Large, complex molecules formed by joining smaller organic molecules, often approaching masses of a million Daltons.

Polymer

A long molecule consisting of many similar or identical building blocks called monomers joined by covalent bonds.

Monomer

A small organic molecular unit that serves as the repeating building block of a polymer.

Dehydration Reaction

A condensation reaction in which two monomers form a covalent bond with the loss of a water molecule.

Hydrolysis

A chemical process that disassembles polymers into monomers through the addition of a water molecule.

Carbohydrates

Biological molecules composed of sugars and their polymers, characterized by the empirical formula $(CH_2O)_n$ which includes oxygen.

Monosaccharides

The simplest sugar monomers, commonly containing 3, 5, or 6 carbons, which serve as fuel and building blocks for polymers.

Disaccharides

Double sugars consisting of two monosaccharides joined together by a glycosidic linkage, commonly used as food.

Glycosidic Linkage

A covalent bond formed between two monosaccharide units via a dehydration reaction, occurring between carbon 1 and carbon 2, 4, or 6 (C1-2, C1-4, C1-6).

Polysaccharides

Long polymers of monosaccharides that function as energy storage materials or structural components in organisms.

Starch

A plant storage polysaccharide composed entirely of $\text{α}$ glucose monomers joined by glycosidic bonds.

Glycogen

An extensively branched storage polysaccharide made of $\text{α}$ glucose monomers, serving as the major storage form of glucose in animal muscle and liver tissues.

Cellulose

An unbranched structural polysaccharide composed of $\text{β}$ glucose monomers where every other monomer is flipped $180^∘$ to form 1-4 glycosidic bonds, creating tough plant cell walls.

Chitin

A structural polysaccharide with modified glucose monomers containing nitrogen, found in the exoskeletons of arthropods and used to make surgical thread.

Aldoses and Ketoses

Classifications of monosaccharides determined by the location of the carbonyl group, located either at the end (aldoses) or within the carbon skeleton (ketoses).

$\alpha$ and $\beta$ Glucose Ring Structures

Ring isomers of glucose defined by the position of the hydroxyl group attached to carbon 1, determining whether polymers form helical storage molecules (starch) or straight structural fibers (cellulose).