Chemistry Comes Alive - Basic Chemistry and Biochemistry

Vocabulary practice flashcards generated from the Chapter 2 lecture on Basic Chemistry and Biochemistry.

Matter

Anything that occupies space and has mass; it possesses measurable volume and mass and exists in solid, liquid, or gas states.

Energy

The capacity to do work or put matter into motion; it has no measurable mass or volume and exists in kinetic and potential forms such as chemical, electrical, mechanical, and radiant energy.

Solution

A homogeneous mixture containing a solvent and dissolved solute particles that are very tiny, do not settle out or scatter light, and cannot be separated by filters or semipermeable membranes.

Colloid

A heterogeneous mixture (emulsion) containing larger solute particles that scatter light, do not settle out, and can be separated by semipermeable membranes but not by filters.

Suspension

A heterogeneous mixture containing very large solute particles that settle out rapidly, may scatter light, and can be separated using filters.

Octet Rule

The tendency of atoms to react in ways that ensure their outermost energy level (valence shell) contains $8$ electrons, achieving chemical stability.

Ionic Bond

A chemical bond formed by the transfer of electrons from one atom to another, resulting in charged ions (anions or cations).

Covalent Bond

A strong chemical bond formed when two or more valence shell electrons are shared between atoms.

Nonpolar Covalent Bond

A covalent bond in which valence electrons are shared equally between atoms, resulting in a balanced charge distribution.

Polar Covalent Bond

A covalent bond formed by the unequal sharing of electrons, producing electronegative and electropositive poles (dipoles).

Hydrogen Bond

A weak intermolecular bond formed when an electropositive hydrogen atom is attracted to an electronegative atom of another molecule.

Synthesis Reaction

An anabolic, endergonic chemical reaction where smaller particles are bonded together to form larger, more complex molecules.

Decomposition Reaction

A catabolic, exergonic chemical reaction where bonds in larger molecules are broken, resulting in smaller, less complex molecules.

Exchange Reaction

A chemical reaction in which bonds are both made and broken (also called a displacement reaction).

Oxidation-Reduction Reaction

A chemical reaction involving electron transfer, where oxidation is the loss of electrons (exergonic) and reduction is the gain of electrons (endergonic).

Catalyst

A substance that increases the rate of a chemical reaction by providing an alternative route with a lower activation energy without being consumed in the process.

Salts

Ionic compounds containing cations and anions (other than $H^+$ and $OH^-$) that dissociate in water into component ions and act as electrolytes.

Acid

A proton donor that tastes sour, produces hydrogen ions ($H^+$) in solution, and turns litmus paper red.

Base

A proton acceptor that tastes bitter, produces hydroxyl ions ($OH^-$) in solution, and turns litmus paper blue.

pH Scale

A relative scale ranging from $0$ to $14$ that measures hydrogen ion concentration ($-\text{log}[H^+]$), where values below $7$ are acidic and above $7$ are basic.

Buffer

A chemical system that resists abrupt and large swings in pH by converting strong acids or bases into weak ones.

Dehydration Synthesis

An organic chemical process where monomers are joined together by removing an $OH$ group from one monomer and an $H$ atom from another, releasing a water molecule ($H_2O$).

Hydrolysis

A chemical reaction that breaks polymers down into monomers by adding a water molecule ($H_2O$), attaching an $OH$ group to one monomer and an $H$ atom to the other.

Carbohydrates

Organic molecules with the general chemical formula $(CH_2O)_n$ that serve as a primary, easily usable source of cellular energy.

Triglycerides

Lipids composed of three fatty acid chains attached to a glycerol backbone in a $3:1$ ratio; function as compact stored energy and insulation for body organs.

Saturated Fatty Acid

A fatty acid chain with no double bonds between carbon atoms, allowing molecules to pack closely together and remain solid at room temperature.

Unsaturated Fatty Acid

A fatty acid chain containing one or more double bonds between carbon atoms, creating kinks that prevent close packing and keep it liquid at room temperature.

Phospholipid

A lipid molecule featuring a glycerol backbone, two nonpolar hydrophobic fatty acid tails, and a polar hydrophilic phosphorus-containing head group; chief constituent of cell membranes.

Steroids

Lipids characterized by a structure of four interlocking hydrocarbon rings, with cholesterol serving as the structural basis for all steroids in the body.

Primary Structure of Protein

The linear sequence of amino acids linked together by peptide bonds to form a polypeptide chain.

Secondary Structure of Protein

The local folding or coiling of a polypeptide chain into spirals ($\alpha$-helices) or zig-zag sheets ($\beta$-pleated sheets), stabilized by hydrogen bonds.

Tertiary Structure of Protein

The compact three-dimensional shape formed when $\alpha$-helices and/or $\beta$-pleated sheets fold together, held by intramolecular bonds.

Quaternary Structure of Protein

The complex structure formed when two or more individual polypeptide chains, each with its own tertiary structure, combine into a single functional protein.

Fibrous Proteins

Strand-like, water-insoluble structural proteins that are highly stable, consist of long parallel polypeptides, and possess little or no tertiary structure (e.g., collagen, keratin).

Globular Proteins

Compact, spherical functional proteins that are water-soluble, environmentally sensitive, and possess tertiary or quaternary structures (e.g., enzymes, hemoglobin, antibodies).

Enzyme

A globular protein that acts as a biological catalyst to regulate and increase the rate of chemical reactions by lowering the activation energy without being consumed.

Deoxyribonucleic Acid (DNA)

A double-stranded nucleic acid coiled into a double helix located in the nucleus; contains deoxyribose sugar and adenine, thymine, cytosine, and guanine bases to store genetic material.

Ribonucleic Acid (RNA)

A single-stranded nucleic acid located primarily in the cytoplasm; contains ribose sugar and adenine, uracil, cytosine, and guanine bases to carry out instructions for protein synthesis.

Adenosine Triphosphate (ATP)

An adenine-containing RNA nucleotide with two additional high-energy phosphate groups that captures chemical energy from nutrient breakdown to directly power cellular work.