main trace elements

iron, iodine, copper, zinc

isotope

same number of protons, different number of neutrons

radiometric dating

a technique which is used to date materials such as rocks or carbon, in which trace radioactive impurities were selectively incorporated when they were formed

compounds

2+ individual elements combined in a fixed ratio

covalent bond

two atoms SHARE one or more pairs of outer shell electrons

ionic bonds

formed when electrons are TRANSFERRED from one atom to the other

What electronegative atoms do hydrogen atoms typically form hydrogen bonds with?

nitrogen, oxygen, fluorine

hydrogen bond

a weak attraction between a covalently bonded (partially positive) hydrogen atom with another electronegative atom

ion

atoms or molecules with electrical charges (from a gain or loss of 1+ electrons)

polar covalent

electrons shared UNEQUALLY (polar molecule)

nonpolar covalent

electrons shared EQUALLY

polar

having electrical or magnetic polarity, two opposites

cohesion

strong tendency to stick together (e.g. transpiration, capillary action)

adhesion

stick to other substances, specifically polar ones (e.g. difficult to separate glass films with water between, capillary action)

surface tension

hydrogen bonds at the surface hold together via cohesion (e.g. leaves sit on top of water)

key properties of water

less dense solid than liquid (expands when freezes), cohesion, adhesion, solvent for polar / charged molecules, high specific heat capacity, high heat of vaporization

specific heat capacity

amount needed to increase temperature by one degree

heat of vaporization

heat needed for a substance to boil

acidic

gives H+ to a solution (protons!), below 7

basic (alkaline)

compound that accepts H+ and gives OH-, above 7

neutral

pure water, not acidic or basic, exactly 7

alkaline

having a pH greater than 7

What does an increase in H+ ions do to a solution?

decrease its pH

pH scale (potential hydrogen)

used to describe a solutions acidity, ranges from 0-14, each unit is 10x change to the H+ of a solution (base 10)

organic compound

made by living cells/organisms, must contain carbon

inorganic compounds

chemical compound that lacks carbon-hydrogen bonds

dehydration synthesis (condensation)

FORMS covalent bonds between monomers to form a polymer by removing a water molecule

hydrolysis

BREAKS bonds between monomers, uses water

carbohydrates

sugars, used for energy fuel, CHO

disaccharide

two monosaccharides linked via dehydration synthesis (e.g. maltose, sucrose, lactose)

glycosidic linkage

when two monosaccharides are joined, hydrogen (-H) links with hydroxyl (-OH) → water, hold hands via one oxygen molecule

glucose

monosaccharide used in photosynthesis for energy

fructose

common monosaccharide in fruits

How do you recognize glucose or fructose?

lots of OHs and Hs attached, C6H12O6 (isomers)

What is starch made of?

amylose and amylopectin with alpha bonds between glucose

starch

sugar storage molecule in plants

amylose

unbranched polysaccharide, linear

amylopectin

branched chains of glucose monomers

cellulose

in plant cell walls (fiber) and fungus / arthropod exoskeletons, made of beta glucose, linked with beta bonds (stronger), lots of cross links

glycogen

sugar storage molecule in animals mainly in liver and muscle cells, linked with alpha bonds

amino group

N connected to two H's, in amino acids (NH2)

carboxyl group

C double bonded to an O and single bonded to an OH, in amino acids (COOH)

R-group (side chains)

determine properties of different amino acids; elements, polarity, charge, shape differentiate

ionic

polar, charged

protein

any of a class of nitrogenous organic compounds that have large molecules composed of one or more long chains of amino acids, CHON(S)

How is secondary structure held together?

hydrogen bonds between the H in the amino group and the O of the carboxyl group

How is tertiary structure held together?

R groups attract each other (with hydrophobic and hydrophilic properties)

How is quaternary structure held together?

bonding interactions of subunits / polypeptide chains

chaperone proteins (chaperonins)

help protein fold properly, make process more efficient

lipids

nonpolar (or amphipathic, mainly nonpolar) and hydrophobic compounds, CHO

triglycerides

THREE fatty acids (chains). ONEEE GLYCEROLLLL. (glycerol backbone), fats and oils

phospholipids

TWO fatty acids and phosphorus (amphipathic), make up plasma membrane

steroids

4 carbon skeleton rings (3 hexagons, 1 pentagon), hormones and cholesterol in animal cell membranes

ester linkage

linkage bond between lipids

sugar-phosphate phosphodiester bonds

linkage bond between nucleic acids

nucleotides

monomers of nucleic acids; made of a nitrogenous base, phosphate group, and a 5-carbon sugar