June 24: Phis 206 Human Physiology - Chapter 2: Atoms, Molecules, and Chemical Bonds

Flashcards covering key vocabulary from the lecture notes on Human Physiology, Chapter 2 focusing on atoms, molecules, chemical bonds and organic molecules.

Atoms

The units of matter that form all chemical substances.

Protons, Neutrons, and Electrons

Subatomic particles that determine the chemical properties of atoms.

Atomic Nucleus

The small volume at the center of an atom where protons and neutrons are confined.

Atomic Number

The number of protons in a chemical element's atom.

Isotopes

Atoms with identical numbers of protons but differing in the number of neutrons.

Gram Atomic Mass

The amount of an element, in grams, equal to the numerical value of its atomic mass.

Avogadro's Constant/Number

6 x 10^23 atoms, the number of atoms in one gram atomic mass of any element.

Ion

An atom that gains or loses one or more electrons, acquiring a net electric charge.

Cations

Ions with a net positive charge.

Anions

Ions with a net negative charge.

Electrolytes

Ionic forms of mineral elements that conduct electricity when dissolved in water.

Molecule

Two or more atoms bonded together.

Chemical Bonds

Chemical bonds where electrons are transferred or shared between atoms.

Covalent Bonds

The strongest type of chemical bond, formed by sharing electrons.

Electronegativity

The measure of an atom's ability to attract electrons in a covalent bond.

Polar Covalent Bonds

Covalent bonds where electrons are unequally shared, resulting in partial charges.

Nonpolar Covalent Bonds

Covalent bonds where electrons are equally or nearly equally shared.

Ionic Bond

The strong attraction between two oppositely charged ions.

Hydrogen Bond

A weak electrical attraction between two polar molecules.

Free Radicals

Atoms or molecules containing a single unpaired electron in their outer shell, making them unstable and highly reactive.

Solutes

Substances dissolved in a liquid.

Solvent

The liquid in which solutes are dissolved.

Solution

A mixture of solutes dissolved in a solvent.

Hydrolysis

The breaking of a chemical bond with the addition of the elements of water.

Condensation (Dehydration)

The process by which molecules are assembled with the removal of water.

Osmosis

The movement of water from regions of low solute concentration to regions of high solute concentration.

Hydrophilic

Molecules that dissolve in water due to polar bonds and/or ionized groups; water-loving.

Hydrophobic

Molecules that do not dissolve in water due to nonpolar covalent bonds; water-fearing.

Amphipathic Molecules

Molecules that have both a polar/ionized region and a nonpolar region.

Solute Concentration

The amount of solute present in a unit volume of solution.

Acid

A molecule that releases protons (hydrogen ions) in solution.

Base

A substance that can accept a hydrogen ion.

Carbohydrates

Organic molecules composed of monosaccharide subunits.

Lipids

Organic molecules composed predominantly of hydrogen and carbon atoms, including fatty acids, triglycerides, phospholipids, and steroids.

Proteins

Organic molecules composed of amino acid subunits, with critical functions in nearly every physiological process.

Nucleic Acids

Organic molecules, DNA and RNA, responsible for the storage, expression, and transmission of genetic information. Composed of nucleotides.

Glucose

Major monosaccharide found in the blood, often called "blood sugar".

Triglycerides

Also known as triacylglycerols, they consist of glycerol bonded to three fatty acids and serve as an energy reserve.

Phospholipids

Lipids similar to triglycerides but with a phosphate group and a small polar or ionized molecule attached, making them amphipathic.

Steroids

Type of lipid composed of four interconnected rings of carbon atoms; examples include cholesterol and steroid hormones.

Amino Acids

The subunit monomers of proteins.

Primary Structure

The specific sequence of amino acids in a protein chain.

Secondary Structure

The coiling or folding of a polypeptide chain due to hydrogen bonds, leading to alpha helices and beta pleated sheets.

Tertiary Structure

The three-dimensional conformation of a polypeptide, resulting from interactions between amino acid side chains.

Quaternary Protein Structure

The structure of proteins with more than one polypeptide chain bonded together.

DNA & RNA

Two classes of nucleic acids comprised of nucleotide subunits containing a phosphate group, a sugar, and a base.

Deoxyribonucleic Acid (DNA)

A nucleic acid with a double helix structure, storing genetic information with the bases adenine, guanine, cytosine, and thymine.

Ribonucleic Acid (RNA)

A nucleic acid consisting of a single chain of nucleotides, with the bases adenine, guanine, cytosine, and uracil.