Chapter 2 - The Chemistry of Life

Vocabulary flashcards for Chapter 2 - The Chemistry of Life, covering topics from the nature of matter to chemical reactions and enzymes.

Cretinism

A condition of severely stunted growth—both physically and mentally, often apparent in infancy, with permanent damage to the brain and body.

Goiter

A condition in which the neck and throat swell up due to an increase in the size of the thyroid gland.

Atom

The basic unit of matter, containing subatomic particles: protons, neutrons, and electrons.

Protons

Positively charged particles found in the nucleus of an atom.

Neutrons

Neutral particles (no charge) found in the nucleus of an atom.

Electrons

Negatively charged particles that orbit the nucleus of an atom in shells or orbitals.

Nucleus

The center of an atom, containing protons and neutrons.

Element

A pure substance that consists entirely of one type of atom.

Atomic Number

The number of protons in the nucleus of an element.

Isotopes

Atoms of the same element that differ in the number of neutrons they contain.

Mass Number

The total number of protons and neutrons in the nucleus of an atom.

Atomic Mass

The weighted average of the masses of an element’s isotopes.

Radioactive Isotopes

Isotopes with unstable nuclei that break down at a constant rate over time, emitting radiation.

Chemical Compound

A substance formed by the chemical combination of two or more elements in definite proportions.

Chemical Formula

A shorthand notation that scientists use to show the composition of compounds.

Valence Electrons

The electrons in an atom’s outer shell that are available to form bonds.

Ionic Bond

A chemical bond formed when one or more electrons are transferred from one atom to another.

Ion

A positively or negatively charged atom resulting from the loss or gain of electrons.

Covalent Bond

A chemical bond formed when atoms share electrons.

Molecule

The structure that results when atoms are joined together by covalent bonds.

Van der Waals Forces

Weak attractions between molecules that occur when they are very close together.

Hydrogen Bond

The attraction between a hydrogen atom with a partial positive charge and another atom with a partial negative charge.

Polar Molecule

A molecule in which the charges are unevenly distributed.

Cohesion

The attraction between molecules of the same substance.

Adhesion

The attraction between molecules of different substances.

Capillary Action

The effect where adhesion between water and glass causes water to rise in a narrow tube against the force of gravity.

Heat Capacity

The amount of energy needed to raise a substance’s temperature.

Mixture

A material composed of two or more elements or compounds that are physically mixed together but not chemically combined.

Solution

A mixture in which all the components are evenly distributed throughout the substance.

Solute

The substance that is dissolved in a solution.

Solvent

The substance in which the solute dissolves.

Suspension

A mixture of water and non-dissolved material in which the movement of water molecules keeps the small particles suspended.

pH Scale

A measurement system used to indicate the concentration of H+ ions in solution, ranging from 0 to 14.

Acid

A compound that releases H+ ions into solution and has a pH value below 7.

Base

A compound that produces hydroxide (OH−) ions in solution and has a pH value above 7.

Buffer

A weak acid or base that can react with strong acids or bases to prevent sharp, sudden changes in pH.

Organic Chemistry

The study of carbon compounds.

Macromolecules

Large organic molecules found in living things, including carbohydrates, lipids, nucleic acids, and proteins.

Polymerization

The process by which larger compounds (polymers) are built by joining smaller ones (monomers) together.

Monomer

A small chemical unit that makes up a polymer.

Polymer

A molecule composed of many monomers; makes up macromolecules.

Carbohydrates

Macromolecules made up of carbon, hydrogen, and oxygen atoms, usually in a ratio of 1:2:1, used for energy storage, structural support, and protection.

Monosaccharides

Single sugar molecules; simple sugars like glucose, fructose, and galactose.

Disaccharide

A compound made by joining together two simple sugars.

Polysaccharides

Macromolecules formed by joining many monosaccharides together.

Glycogen

A polysaccharide used by many animals to store excess sugar.

Starch

A polysaccharide used by plants to store excess sugar.

Cellulose

A polysaccharide that gives plants strength and rigidity; a major component of wood and paper.

Lipids

Macromolecules made mostly from carbon and hydrogen atoms; include fats, oils, and waxes, and are used for energy storage, biological membranes, and waterproof coverings.

Saturated Fatty Acid

A fatty acid in which each carbon atom is joined to another carbon atom by a single bond, containing the maximum possible number of hydrogen atoms.

Unsaturated Fatty Acid

A fatty acid with at least one carbon-carbon double bond; may be monounsaturated or polyunsaturated.

Polyunsaturated Fatty Acid

A fatty acid containing more than one carbon-carbon double bond.

Nucleic Acids

Polymers assembled from nucleotides; store and transmit hereditary or genetic information; RNA and DNA

Nucleotides

Monomers consisting of a 5-carbon sugar, a phosphate group, and a nitrogenous base.

RNA

Ribonucleic acid, contains the sugar ribose.

DNA

Deoxyribonucleic acid, contains the sugar deoxyribose.

Proteins

Macromolecules containing nitrogen as well as carbon, hydrogen, and oxygen; polymers of amino acids.

Amino Acids

Compounds with an amino group (–NH2) on one end and a carboxyl group (–COOH) on the other end; the building blocks of proteins.

Peptide Bonds

Covalent bonds that link amino acids together to form a polypeptide.

Polypeptide

A chain of amino acids linked together by peptide bonds.

Chemical Reaction

A process that changes, or transforms, one set of compounds into another.

Reactants

The elements or compounds that engage in a chemical reaction.

Products

The elements or compounds produced by a chemical reaction.

Activation Energy

The energy that is needed to get a reaction started.

Catalyst

A substance that speeds up the rate of a chemical reaction without being consumed by the reaction.

Enzymes

Biological catalysts, typically proteins, that speed up chemical reactions in cells by lowering activation energies.

Substrates

The reactants of enzyme-catalyzed reactions.

Active Site

A specific region on an enzyme where the substrate binds and catalysis occurs.

Chemical bonds

Holds atoms together in a compound.

Trace elements

Elements that are essential in small amounts.

Thyroxine

A hormone produced in the thyroid gland from tyrosine and atoms of iodine.

Coiling

A secondary structure of a polypeptide chain.

Folding

A secondary structure of a polypeptide chain.

R-group

A side chain that is different for each amino acid.

Receptors

Proteins exposed on cell surfaces that act to certain compounds.

Structural support

Carbohydrates function for structural support in living things.

Chemical messengers

Lipids function as chemical messengers.

Hereditary

Nucleic acids store and transmit genetic or hereditary information.

Conserved

Mass and energy are conserved during chemial transformations.

Spontaneously

Chemical reactions that release energy often occur spontaneously.

Carbonic anhydrase

An enzyme that speeds up the reaction by a factor of 10 million.

Water vapor

Hydrogen gas reacts with oxygen to produce water vapor.

Hydrochloric acid

Produced by the stomach to helo digest food.

Homeostasis

Maintaining a stable internal environment.

Chemical properties

Do not affect structure itself.

Physical properties

Like density and mass.

Van der Waals forces

Responsible for gecko lizard ability to climb walls.

Blue Planet

Earth is called blue planet because it is covered with water.

Trace element

A key trace element was missing from the diet of children and adults in Daxin, China.

Iodine

The human diet requires certain trace elements like Iodine.

Food scientist

Food scientists study food ways to make food healthier and keep fresh.

Macromolecule

Carbohydrates and nucleic acids are macromolecules.

Solution

A base mixed with water created solutions.

Chemical Reaction

Enzymes speed-up a reactions as catalysts.

Matter

Atoms are matter.

Monomer

Amino acid is a monomer.

H2O

Water molecule.

Molecule

Two or more atoms held together by covalent bonds.

Cytosine

Nitrogenous base present in DNA

Thymine

Nitrogenous base present in DNA