AP Bio Unit 1 Vocab

acid

a substance that increases the hydrogen ion concentration of a solution

adhension

the attraction between different types of molecules

aqueous solution

a solution in which water is the solvent

atom

the smallest unit of matter that retains the properties of an element

atomic mass

the total mass of an atom, which is the mass in grams of 1 mole of the atom

atomic number

the number of protons in the nucleus of an atom, unique for each element and designated by a subscript to the left of the elemental symbol

base

a substance that reduces the hydrogen ion concentration of a solution

chemical equilbrium

the state in which the rate of the forward reaction is equal to the rate of the reverse reaction, so the relative products and reactants do not change over time

chemical reaction

the making and breaking of chemical bonds, leading to changes in the composition of matter

cohension

the binding together of like molecules, often by hydrogen bonds

compound

a substance consisting of two or more different elements combined in a fixed ratio

covalent bond

a type of strong chemical bond in which two atoms share one or more pairs of valence electrons

electron

a subatomic particle with a single negative electrical charge and a mass about 1/2000 that of a neutron or proton

electronegativity

the attraction of a given atom for the electrons of a covalent bond

element

any substance that cannot be broken down to any other substances by chemical reactions

Evaporative cooling

the process in which the surface of an object becomes cooler during evaporation, owing to a change of the molecules with the greatest kinetic energy from liquid to gaseous state

hydrogen bond

a type of weak chemical bond that is formed when the slightly positive hydrogen atom of a polar covalent bond in one molecule is attracted to the slightly negative atom of a polar covalent bond in another molecule.

ion

An atom or group of atoms that has gained or lost one or more electrons, thus acquiring a charge.

ionic bond

A chemical bond resulting from the attraction between oppositely charged ions.

isotope

One of several atomic forms of an element, each with the same number of protons but a different number of neutrons, thus differing in atomic mass.

molecular formula

A type of molecular notation representing the quantity of constituent atoms, but not the nature of the bonds that join them.

molecule

two or more atoms held together by covalent bonds

neutron

a subatomic particle having no electrical charge (neutral) with a mass of about 1.7E-24 g, found in the nucleus of an atom

nonpolar covalent bond

a type of covalent bond in which electrons are shared equally between two atoms of similar electronegativity

pH

a measure of hydrogen ion concentration equal to -log[H+] and ranging in value from 0-14.

polar covalent bond

a covalent bond between atoms that differ in electronegativity. The shared electrons are pulled closer to the more electronegative atom, making it slightly negative and the other side slightly positive.

product

a material resulting from a chemical reaction

proton

a subatomic particle with single positive electrical charge, with a mass of about 1.7E10-24 g, found in the nucleus of an atom

reactant

a starting material in a chemical reaction

solute

a substance that is dissolved in a solution

solution

a liquid that is a homogeneous mixture of two or more substances

solvent

the dissolving agent of a solution; water is most versatile solvent

surface tension

a measure of how difficult it is to stretch or break the surface of a liquid; water has a high surface tension due to hydrogen bonding of surface molecules

valence electron

an electron in the outermost electron shell

van der Waals interactions

weak attractions between molecules or parts of molecules that result from localized charge flunctuations

alpha helix

a spiral shape constituting one form of the secondary structure of proteins, arising from a specific pattern of hydrogen bonding

amino acid

an organic molecule posessing both carboxyl and amino groups; monomers of polypeptides

amino group

a chemical group consisting of a nitrogen atom bonded to two hydrogen atoms; can act as a base in solution, accepting a hydrogen ion and acquiring a charge of 1+

antiparallel

the opposite arrangement of the sugar-phosphate backbones in a DNA double helix

ATP

an adenine-containing nucleoside triphosphate that releases free energy when its phosphate bonds are hydrolyzed. This energy is used to drive endergonic reactions in cells

beta pleated sheet

one form of the secondary structure of proteins in which the polypeptide chain folds back and forth. Two regions of the chain lie parallel to each other and are held together by hydrogen bonds

carbohydrate

a sugar (monosaccharide) or one of its dimers (disaccharides) or polymers (polysaccharides)

carboxyl group

a chemical group present in organic acids and consisting of a single carbon atom double bonded to an oxygen atom and also bonded to a hydroxyl group

cellulose

a structural polysaccharide of plant cell walls, consisting of glucose monomers joined by beta glycosidic linkages

chitin

a structural polysaccharide, consisting of amino sugar monomers, found in many fungal cell walls and in the exoskeletons of all anthropods

chloesterol

a steroid that forms an essential component of animal cell membranes and acts as a precursor molecule for the synthesis of other biologically important steroids, such as hormones

dehydration reaction

a chemical reaction in which two molecules covalently bond to each other with the removal of a water molecule

denaturation

in proteins, the process in which a protein unravels and loses its native shape, becoming biologically inactive; in DNA, the separation of two strands of the double helix; occurs under extreme noncellular conditions of pH, salt concentration, and temperature

DNA

a double stranded, helical nucleic acids molecule consisting of nucleotide monomers with a deoxyribose sugar and the nitrogenous bases adenine, cytosine, guanine, and thymine; capable of replicating and determining the inherited structure of a cell’s proteins

disaccharide

a double sugar, consisting of two monosaccharides joined by a glycosidic linkage formed during dehydration synthesis

disulfide bridge

a strong covalent bond formed when the sulfur of one cysteine monomer bonds to the sulfur of another cysteine monomer

enzyme

a macromolecule serving as a catalyst, a chemical agent that changes the rate of a reaction without being consumed by the reaction

fatty acid

a long carbon chain carboxylic acid. varies in length and in number/location of double bonds

triglyceride

three fatty acids linked to a glycerol

functional group

a specific configuration of atoms commonly attached to the carbon skeletons of organic molecules and involved in chemical reactions

glycogen

an extensively branched glucose storage polysaccharide found in the liver and muscle of animals

hydrocarbon

an organic molecule with only carbon and hydrogen

hydrolysis

a chemical process that lyses, or splits molecules by adding water— disassembles polymers to monomers

hydrophobic interaction

weak chemical bond when molecules that not mix with water coalesce to exclude water

hydroxyl group

a chemical group consisting of an oxygen atom joined to a hydrogen atom; called alcohols and are soluble

isomer

one of several compounds with the same molecular formula but different structures and properties

lipid

one of a group of compounds, including fats, phospholipids, and steroids that mix poorly with water

macromolecule

a giant molecule formed by joining smaller molecules, by condensation

monomer

the subunit that serves as building block of polymer

monosaccharide

simplest carbohydrate, active alone or serving as a monomer for disaccharides and polysaccharides

nucleic acids

polmer (polynucleotide) consisting of many nucleotide monomers; blueprint for proteins and all cellular activities through protein action; DNA and RNA

nucleotide

the building block of a nucleic acid, consisting of a five carbon sugar covalently bonded to a nitrogenous base and phosphate group

organic chemistry

the study of carbon compounds

peptide bond

the covalent bond between carboxl group on one amino acid to the amio group on another, formed by dehydration

phosphate group

chemical group with a phosphorous atom bonded to 4 oxygen atoms; important in energy transfer

polymer

a long molecule consisting of many similar/identical monomers linked together

polynucleotide

a polymer consisting of many nucleotide monomers in a chain; nucleotides can be DNA or RNA

polysaccharide

a polymer of many monosaccharides, formed by dehydration

primary structure

the level of protein structure referring to the specific sequence of amino acids

protein

a functional biological molecules consisting of one or more polypeptides folded and coiled into 3D structure

quaternary structure

particular shape of a complex, aggregate protein, defined by the 3D arrangements of its polypeptides

RNA

nucleic acid consisting of nucleotide monomers with ribose sugar and nitrogenous bases

saturated fatty acid

all carbons in hydrocarbon tail are connected by single bonds, maximizing the hydrogen atoms attached to carbon skeleton

secondary structure

localized, repetitive coiling or folding of the polypeptide backbone of a protein due to hydrogen bond formation between constitutents of backbone

starch

a storage polysaccharide in plants, consisting entirely of glucose monomers, joined by glycosidic linkages

steroids

type of lipid with a carbon skeletons with 4 rings and various chemical groups attached

tertiary structure

irregular contortions of a protein molecule due to interactions of side chains in hydrophobic interactions, ionic bonds, hydrogen bonds, and disulfide bridges

trans fat

an unsaturated fat containing one or more trans double bonds

unsaturated fatty acid

fatty acid possessing one or more double bonds between carbons in hydrocarbon tail— reduces hydrogen atoms