Ch.2 Chemicals

Comprehensive vocabulary flashcards covering chemical concepts, molecular bonding, the properties of water, and biological macromolecules as presented in Chapter 2 of the Anatomy & Physiology integrative approach.

Atom

The smallest particle exhibiting chemical properties of an element.

basic

pH > 7

acidic

pH < 7

lipids

• Diverse group of fatty, water-insoluble molecules

• Function as stored energy, cellular membrane components, hormones

polyunsaturated

two or more double bonds

unsaturated

one double bond

saturated

lack double bonds

Lipolysis

breakdown of triglycerides when nutrients are
needed

phospholipids

Amphipathic molecules that serve as chemical barriers of cell membranes

Polysaccharides

Formed from many monosaccharides

Disaccharides

Formed from two monosaccharides

Monosaccharides

Simple sugar monomers

glucose

• Six-carbon carbohydrate

• Most common monosaccharide

• Primary nutrient supplying energy to cells

proteoglycans

attached to GAGs

Glycosaminoglycans (GAGs)

large carbohydrates with attached amine groups

Deoxyribonucleic acid (DNA)

• Double-stranded nucleic acid

• Located in chromosomes in nucleus and in mitochondria

Ribonucleic acid (RNA)

• Single-stranded nucleic acid

• Located in nucleus and in cytoplasm of cell

R groups

distinguish different amino acids from one another

polypeptides

large number of amino acids

Oligopeptide

small number of amino acids

Glycoproteins

proteins with carbohydrate attached

Neutrons

Subatomic particles with a mass of one atomic mass unit (amu) and no charge.

Protons

Subatomic particles with a mass of one amu and a positive charge of one ($+1$).

Electrons

Subatomic particles with a mass approximately $1/1800\text{th}$ of a proton or neutron (negligible) and a negative charge of one ($-1$).

Orbitals

Regions at varying distances from the nucleus where electrons are located.

Atomic number

The number of protons in an atom of an element, located above the symbol name on the periodic table.

Average atomic mass

The mass of both protons and neutrons, shown below the element’s symbol on the periodic table.

Radioisotopes

Isotopes introduced into the body during medical procedures to trace metabolic reactions; for example, using iodine to image the thyroid gland.

Chemical compounds

Stable associations between two or more elements combined in a fixed ratio, classified as ionic or molecular.

Ions

Atoms with a positive charge (cations) or a negative charge (anions) produced from the loss or gain of one or more electrons.

Octet rule

The tendency of atoms to lose or gain electrons to satisfy a state of stability, usually involving eight electrons in the outer shell.

Ionic bonds

Electrostatic forces that bind cations and anions together, often forming structures called salts.

Covalently bonded molecule

A structure where electrons are shared between atoms of two or more different elements, also termed molecular compounds.

Electronegativity

The relative attraction each atom has for electrons; it increases from left to right across a row and bottom to top in a column on the periodic table.

Nonpolar covalent bond

A bond where electrons are shared equally between two atoms, such as in $O-O$ or $C-H$ bonds.

Polar covalent bond

A bond where electrons are shared unequally, resulting in a more electronegative atom developing a partial negative charge (\text{\delta}^{-}).

Amphipathic molecules

Large molecules that contain both polar and nonpolar regions, such as phospholipids.

Hydrogen bond

A weak attraction between a partially positive hydrogen atom and a partially negative atom (usually oxygen in water) of adjacent molecules.

Cohesion

The attraction between water molecules due to hydrogen bonding.

Surface tension

The inward pulling of cohesive forces at the surface of water.

Adhesion

The attraction between water molecules and a substance other than water.

Specific heat

The amount of energy required to increase the temperature of $1\text{\,g}$ of a substance by $1$ degree Celsius.

Heat of vaporization

The heat required for $1\text{\,g}$ of a substance to release molecules from a liquid phase into a gaseous phase.

Hydrophilic

Substances that are "water-loving" and dissolve in water, including polar molecules and ions.

Hydrophobic

Substances that are "water-fearing" and do not dissolve in water, such as nonpolar molecules like fats and cholesterol.

Electrolytes

Substances that dissolve and dissociate in water and can conduct an electric current.

Acid

A substance that dissociates in water to produce $H^+$ and an anion; also known as a proton donor.

Base

A substance that accepts $H^+$ when added to a solution; also known as a proton acceptor.

pH

A measure of the relative amount of $H^+$ in a solution, expressed on a scale from $0$ to $14$.

Neutralization

The process of returning an acidic or basic solution to a neutral pH ($7$) by adding a base or acid, respectively.

Buffers

Substances that help prevent pH changes by accepting $H^+$ from excess acid or donating $H^+$ to neutralize a base.

Biological macromolecules

Large organic molecules synthesized by the body, always containing carbon, hydrogen, and oxygen.

Polymers

Large molecules made of repeating subunits called monomers.

Dehydration synthesis

A chemical reaction where two monomers lose a water molecule ($H_2O$) to form a dimer.

Hydrolysis

A chemical reaction where the addition of water to a dimer or polymer yields individual monomers.

Triglycerides

Lipids used for long-term energy storage, formed from one glycerol and three fatty acids.

Lipogenesis

The formation of triglycerides from glycerol and fatty acids when excess nutrients exist.

Steroids

Lipids composed of hydrocarbons arranged in a multiringed structure, including cholesterol and certain hormones.

Eicosanoids

Modified $20$-carbon fatty acids that act as local signaling molecules in the inflammatory response.

Glycogen

A polysaccharide used by animals to store excess glucose in the liver and skeletal muscle.

Glycogenesis

The process where the liver and skeletal muscle bind glucose monomers together to form glycogen.

Nucleic acids

Biological macromolecules, such as DNA and RNA, that store and transfer genetic information.

Adenosine triphosphate (ATP)

A nucleotide composed of adenine, ribose, and three phosphate groups that serves as the central molecule for chemical energy transfer.

Proteins

• Polymers composed of one or more strands of amino acid monomers linked by peptide bonds.

• synthesis, blood transport, structural support, membrane transport

Denaturation

The change in a protein's complex three-dimensional shape, often due to changes in pH or temperature, which usually renders the protein nonfunctional.