chapter 2 - chemistry of life Flashcards
element
pure substance of one type of atom
compound
substance formed by 2+ elements in definite proportions
isotope
same number of protons but different number of neutrons as the base atom
ion
charged atom
molecule
smallest unit of compound that displays all properties
atomic number
of protons
atomic weight
protons and electrons added together (the electron count is the average of the isotopes and their frequency in nature)
ionic bond
bond by transfer of electrons
covalent bond
bond by sharing electrons
van der waals forces
weak bond from atoms of different elements via +/- attractions
hydrogen bonds
polar covalent bond involving hydrogen (usually H+(N,O, or P))
properties of water
polar, cohesive, adhesive, high heat capacity
solute
substance being dissolved (i.e. salt in water)
solvent
substance doing the dissolving (i.e. water)
mixture
physically mixed compounds/solutions
solution
evenly distributed mixture
suspension
mixture of water and an undissolved substance
pH
scale (0-14) measures the H+ ion concentration; logarithmic scale (each number up is 10x the last one)
acid
compound that forms H+ ions; 0-7 on pH scale
base
compound that forms OH- ions; 7-14 on pH scale
buffer
compound that prevents sharp pH changes
amalgam
mixtures of liquid mercury and another metal
hydrochloric acid (HCl)
one of the most acidic compounds
sodium hydroxide
one of the most basic compounds
buffer system
type of solution that is able to resist changes in its pH when small amounts of an acidic or basic substance is added to it
monomer
small chemical unit that makes up a polymer
polymer
molecule composed of many monomers; makes up macromolecules
carbohydrate (polysaccharide)
macromolecule created from simple sugar (monosaccharide); main source of energy for living things
complex carbs
starch, cellulose, glycogen
lipid
macromolecule created from fatty acid; used to store energy; makes up fat; saturated and unsaturated; phosopholipid
nucleic acid
macromolecule created from neucleotides; contains phosphate, sugar, and base; builds DNA
DNA
deoxyribonucleic acid; double helix shaped; genetic info and genes
RNA
riboneucleic acid; single strand
protein
macromolecule created from amino acid; most diverse of large biological molecules; made from carboxl and amino group
levels of amino acid structure
- primary (o-o-o-o-o chain sequence)
- secondary (helix or ß sheet)
- tertiary (more folding + bonding)
- quaternary (2+ chains folded together)
chemical reaction
changes of chemical properties
reactants
elements/compounds going into a reaction
products
elements/compounds coming out of a recation
activation
energy needed to start a reaction
catalyst
substance that speeds up a reaction
enzyme
protein catalyst that speeds up a biological reaction; are recycled in enzyme cycle
substrate
reactant of enzyme-catalyzed reaction
spontaneous reactions
chemical reactions that release energy (i.e. exothermic spontaneous rxn); ∆E=E2-E1
nonspontaneous reaction
chemical reactions that don’t release energy (i.e. endothermic nonspontaneous rxn); ∆E=E2-E1
how do you increase the rate of a reaction?
use an catalyst (i.e. enzyme)
