A&P 1 Ch. 2 Lecture Exam 1

Matter

anything that takes up space & has mass, made up of atoms

Protons

positive charge

Neutrons

no electrical charge

Electrons

negative charge

Nucleus

contains protons & neutrons

Electron cloud

spherical area that contains electrons

Electron shell

2D representation of electron cloud

Valence shell

outermost shell, determines bonding

Atoms

smallest particle of an element that has chemical characteristics of that element

Atomic number

equal to number of protons in each atom, which is equal to the number of electrons

Mass number

number of protons + number of neutrons

Atomic mass

average mass of naturally occurring isotopes

Ions

an atom with electric charge

Isotopes

versions of elements based on mass number (varies in number of neutrons)

Hydrophobic

Water-fearing (nonpolar, fats, oils)

Hydrophillic

Water-loving (polar, ions)

Ionic bonds

attractions between cations & anions (electrons attraction)

Covalent bonds

strong bonds involving shared electronsP

Peptide bonds

covalent bonds formed between amino acids during protein synthesis by dehydration

Polar covalent bonds

Unequal sharing of electrons because one atom has a disproportionately strong pull on the electrons

Nonpolar covalent bonds

Equal sharing of electrons between atoms that have equal pull on the electrons

Hydrogen bonds

Occur when the positively charged H of one molecule is attracted to the
negatively charged FON of another molecule

Dehydration synthesis

synthetic reaction where water is a product.

Hydrolysis

water is split into two parts that contribute to
the formation of the products (H & OH)

Reversible reaction

Chemical reactions in which the reaction can proceed
either from reactants to products or from products to
reactants (equilibrium)

Exchange reaction

involves decomposition first, then synthesis

Solutions

mixture of liquids, gasses, or solids that are uniformly distributed. (solutes & solvents)

Solutes

the dissolved substances

Salt

Solute that dissociates into cations and anions
other than hydrogen ions and hydroxide ions

Electrolytes

inorganic ions that conduct electricity in solution

pH scale

Has an inverse relationship with H+ concentration
• More H+ ions means lower pH, fewer H+ ions
means higher pH

Acid

proton donor, a solute that adds hydrogen ions to a solution (lower than 7)

Base

proton acceptor, a solute that removes hydrogen ions from a solution (greater than 7)

Buffers

stabilize pH of solutions
• Buffer systems often involve a weak acid
and its related salt (weak base)
• Neutralize strong acids or strong bases
• Carbonic acid–bicarbonate buffer system is
very important in humans

Organic molecule

covalently bonded molecules containing H, C, O and functional groups that determine their chemistry (carbohydrates, proteins, lipids, and nucleic acids)

Macromolecule

made up of monomer subunits

Monomer

molecule

Polymer

formed by identical monomers linking together

Lipids

• mainly hydrophobic molecules duch as fats, oils, and waxes

• made mostly of carbon and hydrogen atoms

• include fatty acids, eicosanoids, glycerides, steroids, phospholipids and glycolipids

Phospholipids

One fatty acid replaced with a phosphate group; polar (hydrophilic)
at one end; nonpolar (hydrophobic) at the other.
• Function: important structural component of cell membranes

Glycolipids

Can be synthesized by our cells, contain a diglyceride attached to a sugar, have hydrophillic heads and hydrophobic tails

Proteins

the most abundant and important organic molecules, contain C, H, O, N, formed by 20 amino acids.

Glycoproteins

• Large proteins + small carbohydrates

• Include enzymes, antibodies, hormones, and components of plasma membranes

• Mucus production

Proteoglycans

large polysaccharides + polypeptides, increase viscosity of fluids

Amino acid

monomer of proteins, consists of central carbon atom, hydrogen atom, amino group (NH2), carboxyl group (COOH), R group

Carbohydrates

contain carbon, hydrogen, and oxygen in 1:2:1 ratio, sugars

Nucleic acids

large organic molecules found in the nucleus, store and process information, DNA/RNA

Nucleotides

monomer of nucleic acids, contain a pentose sugar (deoxyribose or ribose), phosphate group, and nitrogeneous base

Nitrogenous base

Adenine, Guanine, Thymine, Cytosine, Uracil

Deoxyribonucleic acid

DNA, determines inherited characteristics, directs protein synthesis, controls enzyme production, controls metabolism

Ribonucleic acid

RNA, controls intermediate steps in protein synthesis

Adenosine triphosphate

ATP, high-energy compound containing three phosphate groups, derived from nucleotides, stores energy and provides energy

Peptides