BIOL 2401 Chapter 2 - The Chemical Level of Organization Vocabulary Flashcards

Comprehensive vocabulary flashcards covering key terms and concepts from Chapter 2 (The Chemical Level of Organization) study guide.

Matter

Anything that occupies space and has mass.

Mass

A physical property that determines the weight of an object under the influence of gravity.

Subatomic particles

The essential structural units that make up an atom, consisting of protons, neutrons, and electrons.

Proton

A positively charged subatomic particle located in the nucleus of an atom.

Neutron

An uncharged (neutral) subatomic particle located in the nucleus of an atom.

Electron

A negatively charged subatomic particle located in energy levels outside the nucleus, attracted to the positively charged nucleus.

Nucleus

The central core of an atom where protons and neutrons are located.

Element

A pure chemical substance composed of only one type of atom.

Atomic number

The number of protons in the nucleus of an atom, which determines the element's position and chemical identity.

Isotope

Atoms of the same element that have the same atomic number but differ in their number of neutrons.

Valence shell

The outermost electron shell of an atom that determines its chemical reactivity and bonding behavior.

Chemical bond

An attraction or force holding atoms together to form molecules or compounds, representing a form of chemical energy.

Ionic bond

A chemical bond formed by the electrical attraction between oppositely charged ions (cations and anions) after the transfer of electrons.

Ion

An atom or molecule with an electric charge resulting from the loss or gain of one or more electrons.

Cation

A positively charged ion formed when an atom loses electrons.

Anion

A negatively charged ion formed when an atom gains electrons.

Covalent bond

A chemical bond formed when atoms share electrons to fill their valence shells.

Nonpolar covalent bond

A type of covalent bond in which electrons are shared equally between atoms.

Polar covalent bond

A type of covalent bond formed when one atom pulls more strongly on shared electrons than the other atom.

Hydrogen bond

A weak attraction between a partial positive charge on a hydrogen atom and a partial negative charge on an adjacent atom.

Kinetic energy

The energy of motion.

Potential energy

Stored energy resulting from an object's position or structure.

Chemical energy

A form of potential energy stored in the chemical bonds of molecules.

Chemical reaction

A process in which existing chemical bonds are broken or new chemical bonds are formed.

Activation energy

The minimum amount of energy required to initiate a chemical reaction.

Enzyme

A protein catalyst that lowers the activation energy required for a chemical reaction to occur.

Inorganic compound

A compound that generally lacks carbon and hydrogen as primary components, including water, acids, bases, and salts.

Organic compound

A carbon-based compound structurally composed of carbon and hydrogen atoms, including carbohydrates, lipids, proteins, and nucleic acids.

Solution

A uniform fluid mixture consisting of a solvent and one or more dissolved solutes.

Solvent

The fluid medium in a solution that dissolves solute particles.

Solute

The substance dissolved in a solvent within a solution.

Hydrophilic

Substances that readily interact with or dissolve in water.

Hydrophobic

Substances that do not readily interact with or dissolve in water.

Electrolyte

A soluble inorganic substance whose ions dissociate in water and conduct an electrical current.

Acid

A solute that dissociates in water to release hydrogen ions ($H^+$), lowering pH.

Base

A solute that removes hydrogen ions ($H^+$) from solution or releases hydroxide ions ($OH^-$), raising pH.

Salt

An ionic compound containing cations other than $H^+$ and anions other than $OH^-$ that dissociates completely in water.

pH

A measure of the concentration of hydrogen ions in a solution.

pH scale

A numerical scale ranging from 0 to 14 used to measure the acidity or basicity of a solution.

Carbohydrate

An organic compound whose main function in the human body is to serve as a primary energy source.

Glycogen

A polysaccharide that serves as an important storage form of glucose in human tissues.

Triglyceride

A lipid molecule functions as a primary form of energy storage, insulation, and protection in the body.

Phospholipid

A lipid molecule that forms the basic structural bilayer of cell membranes, creating a waterproof barrier.

Protein

An organic macromolecule composed of amino acid chains folded into complex structures to perform vital biological functions.

Amino acid

The fundamental monomer or building block of proteins.

Polypeptide

A chain of amino acids linked together by peptide bonds.

Primary structure (of protein)

The linear sequence of amino acids along a single polypeptide chain.

Secondary structure (of protein)

Localized folding patterns formed by hydrogen bonds along a polypeptide chain, such as alpha-helices or beta-sheets.

Tertiary structure (of protein)

The complex three-dimensional coiling and folding that determines the functional shape of a single polypeptide chain.

Quaternary structure (of protein)

The spatial arrangement and structural interaction resulting from two or more individual polypeptide chains working together.

Globular protein

A compact, rounded, and soluble functional protein.

Fibrous protein

An extended, tough, and insoluble structural protein.

Nucleic acid

An organic macromolecule, such as DNA or RNA, responsible for storing and processing cellular genetic information.

Nucleotide

The structural monomer or building block of nucleic acids, consisting of a sugar, a phosphate group, and a nitrogenous base.

DNA

Deoxyribonucleic acid; a double-stranded nucleic acid that stores genetic instructions.

RNA

Ribonucleic acid; a single-stranded nucleic acid involved in executing genetic instructions during protein synthesis.

Complementary base pairs

The predictable pairing of specific nitrogenous bases in nucleic acids (e.g., Adenine with Thymine/Uracil, and Cytosine with Guanine).

Phosphorylation

The chemical process of attaching a phosphate group to another molecule.

ATP

Adenosine triphosphate; the high-energy compound that serves as the main source of usable energy for human bodily activities.

ADP

Adenosine diphosphate; the molecule produced along with released energy when ATP is broken down.