Biochemistry Basics

Vocabulary flashcards covering key concepts from Biochemistry Basics, including molecular models, molecular properties, functional groups, bonds, and signaling molecules.

Ball-and-stick model

A 3D representation of a molecule where atoms are shown as balls and bonds as sticks to illustrate geometry.

Lewis structure

A 2D diagram showing atoms, all bonds, and lone pairs to represent valence electrons.

Line drawing

A 2D schematic where lines represent covalent bonds and most atoms are not explicitly drawn.

Polar molecule

A molecule with uneven distribution of electron density, leading to partial charges and typically hydrophilicity.

Nonpolar molecule

A molecule with even distribution of electrons, resulting in no permanent dipole and usually hydrophobic.

Acidic

Describes a substance that donates protons (H+) in solution; often associated with carboxyl groups.

Basic

Describes a substance that accepts protons (H+) in solution; often associated with amine groups.

Functional group

A specific group of atoms within a molecule that governs its chemical reactivity.

Carboxyl functional group

The -COOH group; can donate a proton to become -COO− in solution.

Amine functional group

The -NH2 (or -NH3+) group; can accept a proton and become -NH3+.

Hydrophilic

Water-loving; molecules that interact well with water due to polarity or charges.

Hydrophobic

Water-fearing; molecules that do not interact well with water and tend to avoid it.

Hydrogen bond

A weak intermolecular attraction between a hydrogen atom bonded to N, O, or F and another electronegative atom.

Covalent bond

A bond formed by sharing electrons between two nonmetal atoms; an intramolecular bond.

Intramolecular bond

A bond that occurs within a single molecule (e.g., covalent bonds between atoms inside the same molecule).

Intermolecular bond

A bond or attraction between different molecules (e.g., hydrogen bonds between molecules).

pH

A measure of how acidic or basic a solution is on a scale from 0 to 14.

Amino acid

An organic molecule with an amino group (-NH2) and a carboxyl group (-COOH); building blocks of proteins.

Noncyclic AMP

A messenger molecule used in signaling that lacks the cyclic phosphate structure.

Phosphate functional group

A phosphorus-oxygen group (-PO4) found in biological molecules; can bear acidic hydrogens.

Acidic hydrogen

A hydrogen atom bound to a highly electronegative atom (e.g., oxygen in phosphate) that can dissociate as H+ in solution.

Like dissolves like

A saying that polar substances tend to dissolve in polar solvents (like water) and nonpolar in nonpolar solvents (like oil).