Building blocks of matter and biomolecules - Vocabulary

Vocabulary flashcards covering matter, atoms, bonds, water properties, pH, and the basics of organic molecules and nucleic acids.

Matter

Anything that has mass and takes up space.

Element

The basic building blocks of matter that cannot be broken down by chemical means.

Atom

The smallest unit of an element that retains the element’s properties.

Nucleus

The center of an atom that contains protons and neutrons.

Proton

Positively charged subatomic particle located in the nucleus.

Neutron

Electrically neutral subatomic particle located in the nucleus.

Electron

Negatively charged subatomic particle that orbits the nucleus.

Atomic number

The number of protons in an atom (equals the number of electrons in a neutral atom).

Mass number

Protons plus neutrons in the nucleus.

Isotope

Atoms with the same atomic number but different mass due to different numbers of neutrons.

Radioisotope

Radioactive isotope used in dating, imaging, or cancer treatment.

Ion

A charged particle formed when atoms gain or lose electrons.

Ionic bond

Bond formed by transfer of electrons between ions; produces a stable outer shell.

Covalent bond

Bond formed by sharing electrons; results in a stable outer shell.

Water

A universal solvent with properties essential for life, including cohesion, adhesion, and high heat capacity.

Hydrogen bond

Weak bond between a hydrogen atom and a negatively charged atom (often oxygen); holds water molecules together.

Universal solvent

Water’s ability to dissolve many substances.

Cohesion

Attraction between like molecules, e.g., water–water.

Adhesion

Attraction between unlike molecules, e.g., water to a surface.

Surface tension

Tension at the surface of a liquid due to cohesive forces.

High heat capacity

Water’s ability to absorb or release large amounts of heat with little change in temperature.

Density anomaly (ice vs. water)

Solid water (ice) is less dense than liquid water.

pH

A measure of hydrogen ion concentration; scale from 0 to 14 with 7 neutral.

Acids

Substances that dissociate and release hydrogen ions (H+).

Bases

Substances that take up hydrogen ions (H+) or release hydroxide ions (OH−).

Dehydration reaction

Removal of water to link subunits into larger molecules.

Hydrolysis

Addition of water to break larger molecules into subunits.

Carbohydrates

Molecules made of monosaccharide subunits; provide short- and long-term energy and come in simple and complex forms.

Monosaccharide

Simple sugar subunit of carbohydrates.

Lipids

Molecules not soluble in water; provide energy and form cell membranes (fats, oils, phospholipids, steroids).

Fats

Lipids usually of animal origin; solid at room temperature; store long-term energy and cushion organs.

Oils

Lipids usually of plant origin; liquid at room temperature.

Proteins

Molecules made of amino acids; perform diverse roles including hormones, enzymes, antibodies, transport.

Amino acids

Subunits that make up proteins.

Denature

Change in a protein’s shape that causes loss of function.

Primary structure

Linear sequence of amino acids in a protein.

Secondary structure

Localized folding patterns (pleated sheets and helices) in proteins.

Tertiary structure

Three-dimensional shape of a protein.

Quaternary structure

Assembly of multiple polypeptides into a functional protein.

Nucleic acids

Polymers made of nucleotide subunits; include DNA and RNA; function to make proteins.

Nucleotide

Subunit of nucleic acids containing a sugar, phosphate group, and base.

DNA

Deoxyribonucleic acid; stores genetic information; bases A, T, C, G.

RNA

Ribonucleic acid; helps convert genetic information into proteins; bases A, U, C, G.

Adenine (A)

Purine base that pairs with thymine (DNA) or uracil (RNA).

Guanine (G)

Purine base that pairs with cytosine.

Cytosine (C)

Pyrimidine base that pairs with guanine.

Thymine (T)

Pyrimidine base that pairs with adenine in DNA.

Uracil (U)

Pyrimidine base that pairs with adenine in RNA (replaces thymine).

Base pairing (A–T, G–C)

Rules describing which bases pair together in DNA (A with T, G with C).