General Biology I - Chemistry of Life and Biological Introduction

Comprehensive vocabulary flashcards covering the chemical foundations of biology, functional groups, biological macromolecules, protein structure, cellular organization, biological hierarchy, and intro concepts.

Solid

State of matter characterized by particles held together by strong bonds in a fixed arrangement.

Liquid

State of matter characterized by weak bonds between particles, allowing them to flow while maintaining a constant volume.

Gas

State of matter in which particles have no bonds between them and move freely to fill any volume.

Plasma

High-energy state of matter characterized by ionization, consisting of free electrons and positive ions/protons.

Proton

Positively charged subatomic particle located in the nucleus of an atom.

Neutron

Electrically neutral subatomic particle located within the atomic nucleus.

Electron

Negatively charged subatomic particle that orbits around the nucleus of an atom.

Atomic Number

The number of protons in the nucleus of an atom, which uniquely identifies a chemical element.

Atomic Mass

The total combined mass of the protons, neutrons, and electrons in an atom.

Isotope

An alternate form of an element having the same number of protons but a different number of neutrons, such as radioactive ${}^{14}\text{C}$.

Valence

The bonding capacity of an atom, determined by the number of unpaired electrons required to complete its outer electron shell.

Ionic Bond

Chemical bond formed by the complete transfer of one or more electrons from one atom to another, resulting in oppositely charged ions.

Covalent Bond

Chemical bond formed when two atoms share one or more pairs of electrons.

Electronegativity

The measure of an atom's attraction for shared electrons in a covalent bond.

Nonpolar Covalent Bond

Type of covalent bond where electrons are shared equally between two atoms of similar electronegativity.

Polar Covalent Bond

Type of covalent bond in which electrons are shared unequally, producing a partial negative charge on one atom and a partial positive charge on the other.

Hydrogen Bond

A weak non-covalent attraction between a partially positive hydrogen atom of one polar molecule and an electronegative atom of another molecule.

Cohesion

The tendency of like molecules to hold together, such as hydrogen bonds holding water molecules together during transport from plant roots to leaves.

Surface Tension

A measure of how difficult it is to stretch or break the surface of a liquid, allowing insects like the water strider to stay atop water.

Acid

A substance that increases the hydrogen ion concentration of a solution, resulting in a $\text{pH}$ value from $0$ to less than $7$.

Base

A substance that decreases the hydrogen ion concentration or increases alkalinity of a solution, resulting in a $\text{pH}$ value above $7$ up to $14$.

pH

A measure of the acidity or alkalinity of a solution on a scale from $0$ to $14$, where $7$ is neutral.

Buffer

A substance that minimizes changes in $\text{pH}$ by accepting hydrogen ions when they are in excess and donating them when depleted.

Dehydration Reaction

A reaction in which two monomers are covalently bonded to each other with the simultaneous loss of a water molecule ($\text{H}_2\text{O}$).

Hydrolysis

A chemical reaction that breaks polymers into monomers by the addition of a water molecule ($\text{H}_2\text{O}$).

Hydroxyl Group

A functional group consisting of a hydrogen atom bonded to an oxygen atom ($-\text{OH}$).

Carbonyl Group

A functional group consisting of a carbon atom double-bonded to an oxygen atom ($-\text{CO}$), found in aldehydes and ketones.

Carboxyl Group

A functional group consisting of a carbon atom double-bonded to an oxygen and single-bonded to a hydroxyl group ($-\text{COOH}$), which acts as an acid.

Amino Group

A functional group consisting of a nitrogen atom bonded to two hydrogen atoms ($-\text{NH}_2$), which acts as a base.

Sulfhydryl Group

A functional group consisting of a sulfur atom bonded to a hydrogen atom ($-\text{SH}$).

Phosphate Group

A functional group consisting of a phosphorus atom bonded to four oxygen atoms ($-\text{PO}_4$).

Monosaccharide

The simplest carbohydrate monomer, such as glucose, existing in straight-chain or ring forms.

Disaccharide

A double sugar consisting of two monosaccharides joined by a dehydration synthesis reaction, such as maltose or sucrose.

Polysaccharide

A long polymer chain composed of many monosaccharides joined by dehydration reactions, such as starch, glycogen, or cellulose.

Cellulose

A structural polysaccharide found in plant cell walls consisting of glucose monomers that cannot be hydrolyzed by most animals, functioning as insoluble fiber.

Triglyceride

A lipid formed by linking three fatty acid molecules to a single glycerol backbone.

Saturated Fatty Acid

A fatty acid whose hydrocarbon tail contains only single bonds between carbons, maximizing the number of attached hydrogen atoms.

Unsaturated Fatty Acid

A fatty acid possessing one or more double bonds between carbons in its hydrocarbon tail, creating kinks in the chain.

Phospholipid

A lipid molecule composed of a hydrophilic polar head and two hydrophobic hydrocarbon tails, forming the bilayer foundation of cell membranes.

Steroid

A type of lipid characterized by a carbon skeleton composed of four fused carbon rings, such as cholesterol and sex hormones.

Enzyme

A biological macromolecule, usually a protein, that acts as a catalyst to speed up specific chemical reactions.

Active Site

The specific region on an enzyme where a substrate molecule binds and undergoes chemical reaction.

Amino Acid

An organic monomer consisting of a central carbon bonded to a hydrogen atom, an amino group, a carboxyl group, and a variable R group.

Peptide Bond

The covalent bond connecting the carboxyl group of one amino acid to the amino group of another formed through a dehydration reaction.

Denaturation

A process in which a protein loses its native shape and structural integrity, rendering it biologically inactive.

Primary Structure

The first level of protein structure, defined as the specific, linear sequence of amino acids in a polypeptide chain.

Secondary Structure

Localized coiling or folding of a polypeptide backbone, such as the $\alpha\text{-helix}$ or $\beta\text{-pleated sheet}$, stabilized by hydrogen bonds.

Tertiary Structure

The overall three-dimensional shape of a polypeptide resulting from interactions between the side chains (R groups) of various amino acids.

Quaternary Structure

The overall protein structure resulting from the aggregation of two or more individual polypeptide chains, such as in hemoglobin.

Nucleotide

The monomer of nucleic acids, consisting of a $5\text{-carbon}$ sugar covalently bonded to a nitrogenous base and a phosphate group.

Gene

A discrete unit of hereditary information located on a chromosome, consisting of a specific sequence of DNA.

Cell

The fundamental, basic structural and functional unit of all living organisms.

Tissue

An integrated group of similar cells that perform a specific function within an organism.

Organ

A specialized center of body function composed of several different types of tissues working together.

Organ System

A group of organs that work together in performing vital body functions.

Population

A group of individuals of the same species living in a specified geographic area at the same time.

Community

All the organisms of different species inhabiting a particular ecosystem or defined area.

Ecosystem

All the organisms in a given area along with the nonliving abiotic factors with which they interact.

Biosphere

The entire portion of Earth inhabited by life, encompassing all planet ecosystems.

Taxonomy

The branch of biology dedicated to naming and classifying species into a biological hierarchy.

Prokaryote

A unicellular organism that lacks a membrane-enclosed nucleus and membrane-bound organelles.

Eukaryote

An organism whose cells contain a membrane-enclosed nucleus and membrane-enclosed organelles.

Natural Selection

The evolutionary mechanism published by Charles Darwin in $1859$, wherein individuals with advantageous inherited traits survive and reproduce at higher rates.

Hypothesis

A tentative, testable explanation for a set of observations in the scientific method.