Bio Ch 3 Flashcards
Inorganic chemistry
the chemistry of nonliving matter
Organic chemistry
the chemistry of living organisms
Organic molecules
molecules that contain both carbon and hydrogen atoms
Biomolecules
4 classes of organic compounds in any living thing - carbohydrates, lipids, proteins, and nucleic acids
Functional group
specific combo of bonded atoms that always reacts in the same way, regardless of the particular carbon skeleton
Hydrophobic
not soluble in water
hydrophilic
soluble in water
Isomers
(Greek, isos, equal & meros, part/portion); organic molecules that have identical molecular formulas but a different arrangement of atoms
Polymers
largest of the biomolecules; constructed by linking together a large number of the same type of subunit
Monomers
subunits of polymers
Dehydration reaction
chemical reaction in which a water molecule is released during the formation of a covalent bond
Hydrolysis reaction
(Greek, hydro, water; lyse, break); opposite of dehydration reaction; breaks down biomolecules by adding water to them; an -OH group from water attaches to one subunit and an -H from water attaches to the other subunit
Enzyme
required for cells to carry out dehydration and hydrolysis reactions; a molecule that speeds a reaction by bringing reactants together and helping them to form new molecules; it participates in the reaction but is unchanged by it
Carbohydrates
almost universally used as an immediate energy source in living things; also play structural role in a variety of organisms; majority of carbohydrates have a carbon to hydrogen to oxygen ratio of 1:2:1; “carbon-water”; includes single sugar molecules and chains of sugars; monomer subunits = monosaccharides assembles into long polymer chains called polysaccharides
Monosaccharides
(Greek, monos, single & sacchar, sugar); consist of only a single sugar molecule; called simple sugars; can have a carbon backbone of 3-7 carbons
Glucose
6 carbon atoms; hexose; C6H12O6; critical to biological function
Hexose
(Greek, hex, six); type of sugar with 6 carbon atoms
Ribose & deoxyribose
5 carbon atoms; pentose sugars; significant b/c they are found respectively in the nucleic acids RNA & DNA
Pentose sugar
(Gk, pent, 5); sugar with 5 carbon atoms
Disaccharide
Contains 2 monosaccharides that have joined during a dehydration reaction
Polysaccharides
polymers of monosaccharides; some are short-term energy storage molecules; when an organism requires energy, the polysaccharide is broken down to release sugar molecules; helical shape
Starch
storage polysaccharide found in plants that is composed of glucose molecules joined in a linear fashion with few side chains; plants store glucose as this
Glycogen
animals store glucose as this; storage polysaccharide composed of glucose molecules joined in a linear fashion but having numerous branches
Cellulose
structural polysaccharide in plants
Chitin
structural polysaccharide in animals & fungi
Peptidoglycan
structural polysaccharide in bacteria
Lipids
(Gk, lipos, fat); insoluble in water due to hydrocarbon chains; class of organic compounds that tends to be soluble in nonpolar solvents; includes fats and olis
Trans-fats
unintended consequence of hydrogenation; increase LDL/bad cholesterol, lower HDL/good cholesterol; increases risk of CHD & heart attack
Fat
organic molecule that contains glycerol and 3 fatty acids; energy storage molecule
Oil
triglyceride, usually of plant origin, that is composed of glycerol & 3 fatty acids & is liquid in consistency due to many unsaturated bonds in the hydrocarbon chains of the fatty acids
Fatty acid
Consists of long hydrocarbon chain with an even number of carbons and an -COOH (carboxyl) group at one end; most contain 16 or 18 carbon atoms per molecule; either saturated or unsaturated
Saturated fatty acids
have no double bonds between the carbon atoms & contain as many hydrogens as they can potentially hold
Unsaturated fatty acids
have double bonds in the carbon chain, which reduces the number of bonded hydrogen atoms; double bonds may have chemical groups arranged on the same side (termed cis configuration) or on opposite sides (termed trans configuration)
Glycerol
3-carbon compound with 3 -OH groups; -OH groups are polar, making glycerol soluble in water
Triglycerides
AKA fats/oils; 3 fatty acids attached to each glycerol molecule
Phospholipids
(Gk, phos, light & lipos, fat); contain a phosphate group; constructed like a fat, except that in place of the 3rd fatty acid attached to glycerol, there is a polar phosphate group
Steroids
lipids that have entirely different structures from those of fats; have skeletons of 4 fused carbon rings
Waxes
long-chain fatty acids bond with long-chain alcohols; solid at room temperature because they have a high melting point; hydrophobic, resistant to degradation
Proteins
(Gk, proteios, 1st place); of primary importance to the structure & function of cells; as much as 50% of the dry weight of cells consists of proteins; functions = metabolism, support, transport, defense, regulation, motion
Hemoglobin
complex protein that transports oxygen to tissues & cells
Peptide bond
resulting covalent bond between 2 amino acids
Peptide
2+ amino acids bonded together
Polypeptide
chain of many amino acids joined together by peptide bonds
Amino acid
protein monomer with an -NH2 (amino) group & a -COOH (acid) group; 3rd group = R (rest of molecule)
Fibrous proteins
structural proteins, exist only as helices or pleated sheets that hydrogen-bond to each other; ex. keratin, silk
Globular proteins
ball up into rounded shapes; have tertiary structure; most of the proteins in the body; soluble in water or salt solution; includes albumins, globulin, histones
Denatured
when a protein loses its natural shape
Chaperone proteins
help new proteins fold into their normal shape
Prions
misfolded proteins that cause other proteins of the same type to fold the wrong way
Nucleic acids
polymers of nucleotides, store info, include instructions for life, and conduct chemical reactions
DNA (deoxyribonucleic acid)
type of nucleic acid that not only stores info about how to copy/replicate itself, also specifies the order in which amino acids are to be joined to make a protein
RNA (ribonucleic acid)
type of amino acid with multiple uses; messenger RNA = temporary copy of a gene in the DNA that specifies what the amino acid sequence will be during the process of protein synthesis; transfer RNA = necessary in synthesizing proteins, helps translate the sequence of nucleic acids in a gene into the correct sequence of amino acid during protein synthesis; ribosomal RNA (rRNA) = enzyme to form the peptide bonds between amino acids in a polypeptide
Coenzymes
nonprotein organic molecules, help regulate enzymatic reactions
ATP
adenosine triphosphate; special nucleotide that stores large amounts of energy needed for synthetic reactions and for various other energy-requiring processes in cells
Nucleotide
monomer of DNA & RNA consisting of a 5-carbon sugar bonded to a nitrogenous base & a phosphate group; composed of 3 types of molecules: pentose sugar, phosphate (phosphoric acid), & a nitrogen-containing base
Complementary base pairing
between strands of DNA, thymine (T) is always paired with adenosine (A) & guanine (G) is always paired with cytosine (C); number of purine bases (A & G) always = number of pyrimidine bases (T & C)
ADP
adenosine diphosphate; nucleotide with 2 phosphate groups that can accept another phosphate group and become ATP
