BIOL 105 General Biology Exam Review

Comprehensive vocabulary flashcards covering BIOL 105 Lectures 2 through 6 (Chapters 2.1-4.3), focusing on atomic structure, chemical bonds, water chemistry, organic macromolecules, amino acids, and cell biology.

Independent Variable

The experimental factor that is intentionally manipulated by researchers to observe its effect.

Dependent Variable

The factor measured in an experiment to evaluate the effect of the manipulated independent variable.

Peromyscus polionotus

The species of mouse studied by Francis B. Sumner and Hopi Hoekstra to investigate coat coloration and natural selection driven by visual predators across beach and inland habitats.

Atomic Number

The total number of protons contained within the nucleus of an element's atom.

Mass Number

The total sum of protons plus neutrons in the nucleus of an atom.

Isotopes

Atoms of the same element that share the same number of protons but differ in their number of neutrons.

Valence Shell

The outermost electron shell of an atom, which can form chemical bonds

Electronegativity

An atom's attraction for the shared electrons within a covalent bond.

Nonpolar Covalent Bond

A covalent bond in which electrons are shared equally between two atoms of similar electronegativity.

Polar Covalent Bond

A covalent bond when two atoms share electrons unequally

Ionic Bond

A chemical bond resulting from the electrostatic attraction between oppositely charged ions (a cation and an anion).

Hydrogen Bond

A weak non-covalent attraction occurring between a partially negatively charged atom and a partially positively charged hydrogen atom.

Chemical Equilibrium

The state in a chemical reaction where the forward and reverse reactions proceed at identical rates, offsetting each other completely.

Cohesion

The property of water molecules staying closely held together due to hydrogen bonding.

Adhesion

The clinging of one substance to a different substance, such as water hydrogen-bonding to cell walls in plant xylem.

Surface Tension

A measure of how difficult it is to stretch or break the surface of a liquid, directly related to cohesion.

Specific Heat

The amount of heat energy that must be absorbed or lost for $1\text{\text{ g}}$ of a substance to alter its temperature by $1\text{\text{ \textdegree C}}$.

Evaporative Cooling

a natural process that lowers air temperature by turning liquid water into vapor water

Solvent

The dissolving agent within a solution.

Solute

The substance that is dissolved in a solution.

Hydrophilic

Having an affinity for water; describes polar or charged substances that interact readily with water.

Hydrophobic

Lacking an affinity for water; describes nonpolar substances (such as oils) that repel water.

Acid

A substance that increases the hydrogen ion ($\text{H}^+$) concentration of a solution by donating protons upon dissolving in water.

Base

A substance that reduces the hydrogen ion ($\text{H}^+$) concentration of a solution by absorbing protons or releasing hydroxide ions ($\text{OH}^-$).

Buffer

A substance that minimizes changes in the concentrations of $\text{H}^+$ and $\text{OH}^-$ in a solution, typically comprising a weak acid and its conjugate base.

Hydrocarbons

Organic molecules composed exclusively of carbon and hydrogen atoms.

Isomers

molecules that share molecular formula but differ in arrangement of atoms

Functional Groups

Specific chemical groups attached to carbon skeletons that directly participate in chemical reactions and dictate molecular function.

ATP (Adenosine Triphosphate)

An organic molecule consisting of adenosine attached to three phosphate groups, functioning as the primary energy currency in cells.

Polymer

A long molecular chain consisting of numerous similar or identical building blocks linked by covalent bonds.

Monomer

The repeating small subunit molecule that serves as the building block of a polymer.

Dehydration Reaction

A chemical reaction in which two monomers become covalently bonded to each other with the removal of a water molecule.

Hydrolysis

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

Peptide Bond

The covalent linkage formed between the carboxyl group of one amino acid and the amino group of another through dehydration synthesis.

Primary Structure

The unique linear sequence of amino acids in a polypeptide chain, encoded directly by genetic information.

Secondary Structure

The local folding pattern of a polypeptide backbone held together by hydrogen bonds

Tertiary Structure

The overall three-dimensional shape of a single polypeptide chain determined by interactions among side chain (R group) functional groups.

Quaternary Structure

The overall protein structure resulting from the association and aggregation of two or more individual polypeptide subunits.

Monosaccharides

Simple sugar monomers (such as glucose, galactose, and fructose) that adhere to the molecular formula $\text{C}_n\text{H}_{2n}\text{O}_n$.

Glycosidic Linkage

A covalent bond joining two monosaccharides together via a dehydration reaction.

Polysaccharides

Complex carbohydrate polymers consisting of many monosaccharide monomers linked together (e.g., starch, glycogen, cellulose, chitin).

Fatty Acid

the basic building blocks of fats consisting of a long hydrocarbon chain.

Saturated Fatty Acid

A fatty acid whose carbon skeleton contains no double bonds, maximizing the number of bonded hydrogen atoms.

Unsaturated Fatty Acid

A fatty acid possessing one or more double bonds in its hydrocarbon chain, creating a reduction in attached hydrogens.

Amphipathic

Describing a molecule that contains both distinct hydrophobic and hydrophilic regions, such as a phospholipid.

Nucleotide

The monomer of nucleic acids, consisting of a nitrogenous base, a pentose sugar, and one to three phosphate groups.

Phosphodiester Bond

The covalent linkage joining nucleotides along a nucleic acid strand, connecting the phosphate at the $5'$ carbon of one sugar to the hydroxyl at the $3'$ carbon of the next.

Purines

Nitrogenous bases containing a two-ring structure, specifically adenine (A) and guanine (G).

Pyrimidines

Nitrogenous bases containing a single six-membered ring structure, specifically cytosine (C), thymine (T), and uracil (U).

Cell Fractionation

A biochemical laboratory technique using centrifugation to separate cellular components by size and density for individual functional analysis.

Prokaryotic Cell

a simple single celled organism that does not have a nucleus or other membrane bound parts

Eukaryotic Cell

A cell type possessing membrane-bound organelles and a true, double-membrane-enclosed nucleus housing its genetic material.

Plasma Membrane

A selective phospholipid bilayer barrier containing embedded proteins and cholesterol that encloses the cell cytosol and regulates molecular transport.

Ribosomes

Cellular complexes of rRNA and protein responsible for carrying out protein synthesis in the cytosol or attached to the endoplasmic reticulum.

Peptidoglycan

A rigid polymer consisting of carbohydrate chains cross-linked by protein fragments that constitutes the cell walls of most bacteria.

Nucleolus

A prominent structure within the non-dividing eukaryotic nucleus responsible for synthesizing ribosomal RNA (rRNA).

Chromatin

The complex of DNA and associated histone proteins that makes up eukaryotic chromosomes inside the nucleus.