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CHAPTER 2- Chemical Composition of the Body

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acid
molecule capable of releasing a H+ ; solution having an H+ concentration greater than that of pure water (pH less than 7)
acidic solution
any solution with a pH less than 7
acidity
concentration of free, unbound hydrogen ion in a solution; the higher the H+ concentration, the greater the acidity
adenine
one of the four bases making up DNA; also a breakdown product of ATP used as a neurotransmitter
adenosine diphosphate (ADP)
two-phosphate product of ATP breakdown
adenosine triphosphate (ATP)
nucleotide that transfers energy from metabolism to cell functions during its breakdown to ADP and release of Pi
alkaline solution
any solution having [H+] lower than that of pure water (pH greater than 7)
alpha helix
coiled regions of proteins or DNA formed by Hydrogen bonds
amino acid
molecule containing amino group, carboxyl group, and side chain attached to a carbon atom; molecular subunit of protein
amino acid side chain
the variable portions of amino acids; may contain acidic or basic charged regions, or may be hydrophobic
amino group
--NH2; ionizes to NH3
amphipathic
a molecule containing polar or ionized groups at one end and nonpolar groups at the other...
anion
negatively charged ion
atom
smallest unit of matter that has unique chemical characteristics; has no net charge
atomic nucleus
dense region, consisting of [protons and neutrons, at center of atom...
atomic number
number of protons in nucleus of atom
atomic weight
value that indicates an atom's mass relative to mass of other types of atoms based on assignment of a value of 12 to carbon atom...
base
any molecule that can combine with H+
beta pleated sheet
a form of secondary protein structure determined by the relative hydrophobicity of amino acid side chains
carbohydrate
substance composed of carbon, hydrogen, and oxygen according to general formula Cn(H2O)n
carboxyl group
--COOH; ionizes to carboxyl ion (--COO-)
cation
ion having net positive charge...
chemical element
specific type of atom...
concentration
amount of solute per unit volume of solution
conformation
3D shape of a molecule...
covalent bond
chemical bond between two atoms in which each atom shares one of its electrons with the other...
cytosine
pyrimidine base in DNA and RNA
dehydration
type of chemical reaction in which two smaller molecules, such as amino acids, are joined to form a larger molecule; a single molecule of water is lost in the process...
deoxyribonucleic acid (DNA)
nucleic acid that stores and transmits genetic information; consists of double strand of nucleotide subunits that contain deoxyribose...
deoxyribose
a ribose molecule with a single hydroxyl group removed; a component of DNA
disaccharide
carbohydrate molecule composed of two monosaccharides
disulfide bond
R-S-S-R...
electrolyte
substance that dissociates into ions when in aqueous solution...
electron
subatomic particle that carries one unit of negative charge...
electronegativity
measure of an atom's ability to attract electrons in a covalent bond...
fatty acid
carbon chain with carboxyl group at one end through which chain can be linked to glycerol to form triglyceride...
free radical
...atom that has an unpaired electron in its outermost orbital; molecule containing such an atom
glucose
major monosaccharide in the body; a six-carbon sugar, C6H12O6...
glycerol
three-carbon carbohydrate; forms backbone of triglyceride...
glycogen
highly branched polysaccharide composed of glucose subunits; major carbohydrate storage form in body...
glycoprotein
protein containing covalently linked carbohydrates
gram atomic mass
amount of element in grams equal to the numerical value of its atomic weight...
guanine
purine base in DNA and RNA
hexose
any six-carbon sugar, such as glucose...
hydrogen bond
weak chemical bond between two molecules or parts of the same molecule in which negative region of one polarized substance is electrostatically attracted to a positively charged region of polarized hydrogen atom in the other
hydrolysis
breaking of chemical bond with addition of elements of water (-H and -OH) to the products formed; aka hydrolytic reaction
hydrophilic
attracted to, and easily dissoved in, water
hydrophobic
not attracted to, and insoluble in, water
hydroxyl group
-OH
ion
atom or small molecule containing unequal number of electrons and protons and therefore carrying a net positive or negative electrical charge
ionic bond
strong electrical attraction between two oppositely charged ions
isotope
an atom consisting of one or more additional neutrons than protons in its nucleus
lipid
molecule composed primarily of carbon and hydrogen and characterized by insolubility in water
macromolecule
large organic molecule composed of up to thousands of atoms, such as a protein or polysaccharide
mole
the amount of the compound in grams equal to its molecular weight
molecular weight
sum of atomic weights of all atoms
molecule
chemical substance formed by linking atoms together
monosaccharide
carbohydrate consisting of one sugar molecule, which generally contains five or six carbon atoms
monounsaturated fatty acid
a fatty acid, such as oleic acid, in which one carbon-carbon double bond is formed within the hydrocarbon chain due to the removal of two hydrogen atoms
multimeric protein
a protein in which two or more proteins are associated via hydrogen bonds, hydrophobic attractions, and other forces, to yield a single, larger protein
mutation
any change in base sequence of DNA that changes genetic information
neutral solution
a solution that is neither basic nor acidic (pH= 7)
neutron
noncharged component of the nuin moleculecleus of an atom
nonpolar covalent bond
a bond between two atoms of similar electronegativities
nonpolar molecule
any molecule with characteristics that favor solubility in oil and decreased solubility in water
nucleic acid
nucleotide polymer in which phosphate of one nucleotide is linked to the sugar of the adjacent one; stores and transmits genetic information; includes DNA and RNA
nucleotide
molecular subunit of nucleic acid; purine or pyrimidine base, sugar, and phsosphate
pentose
any five-carbon monosaccharide
peptide
short polypeptide chain; by convention , having fewer than about 50 amino acids
peptide bond
polar covalent chemical bond joining the amino and carboxyl groups of two amino acids; forms protein backbone
pH
expression of a solution's acidity;
phospholipid
lipid subclass similar to triglyceride except that a phosphate group (--PO4 ^2-) and small nitrogen-containing molecule are attached to third hydroxyl group of glycerol; major component of cell membranes
polar covalent bond
covalent chemical bond in which two electrosn are shared unequally between two atoms of different electronegativites
polar molecule
pertaining to molecule or region of molecule containing polar covalent bonds or ionized groups
polymer
large molecule formed by linking together smaller similar subunits
polypeptide
polyer consisting of amino acid subunits joined by peptide bonds; aka peptide
polysaccharide
large carbohydrate formed by linking monosaccharide subunits together
polyunsaturated fatty acid
fatty acid that contains more than one double bond
primary structure
the amino acid sequence of a protein
protein
large polymer consisting of one or more sequences of amino acid subunits joined by peptide bonds to form a functional molecule with multiple levels of structure
proton
positively charged subatomic particle
purine
double-ring, nitrogen-containing subunit of nucleotide; adenine or guanine
pyrimidine
single-ring, nitrogen-containing subunit of nucleotide; cytosine, thymine, or uracil
quaternary structure
formed when two or more proteins associate with each other by hydrogen bonds and other forces
ribonucleic acid (RNA)
single-stranded nucleic acid involved in transcription of genetic information and translation of that information into protein structure; contains the sugar ribose
ribose
the sugar backbone of RNA
saturated fatty acid
fatty acid whose carbon atoms are all linked by single covalent bonds
secondary structure
the alpha-helical and beta pleated structures of a protein
solute
substances dissolved in a liquid
solution
liquid (solvent) containing dissolved substances (solutes)
solvent
liquid in which substances are dissolved
steroid
lipid subclass; molecule consists of four interconnected carbon rings to which polar groups may be attached
strong acid
acid that inonized completely to form hydrogen ions corresponding anions when dissolved in water
sucrose
disaccharide composed of glucose and fructose
tertiary structure
the 3D folded structure of a protein formed by hydrogen bonds, hydrophobic attractions, electrostatic interactions and cysteine cross-bridges
thymine
pyrimidine base in DNA but not RNA
trace element
mineral present in body in extremely small quantities
trans fatty acid
an unsatturated fatty acid in which the H atoms around a carbon:carbon double bond are distributed in a trans orientation (on the same side); implicated in a variety of negative health consequences
triglyceride
subclass of lipids composed of glycerol and three fatty acids
unsaturated fatty acid
fatty acid containing one or more double bonds
uracil
pyrimidine base; present in RNA but not DNA
van der Waals forces
weak forces between atoms and molecule due to transient electrical forces generated by the orbits of electrons in the outer energy shells of atoms
weak acid
acid whose molecule do not completely ionize to form hydrogen ions when dissolved in wwater
sickle-cell disease
a mutation in the gene for the beta subunits of hemoglobin result. in the replacement of a single glutamic acid residue with one of valine. glutatmic acid has a charged, polar side grou, whereas valine ahs a nonpolar side group. the nonpolar groups causes many hemoglobin molecule to bond with each other.
sickle-cell trait
individuals with sickle-cell trait (SCT) have one normal inherited form one parent and one gene with a mutation inherited from the other parent