Biochem. Test Flashcards
chemical change
substance combines with another to form a new substance; irreversible; example: rust on iron
physical change
effects form of a substance but not its composition; reversible; example: melting ice then re-freezing it
smallest particle of matter
atom
atomic number
number of protons in the nucleus of an atom
atomic mass
number of protons plus neutrons in an atom
types of bonding
covalent and ionic
covalent bonding
2 atoms share electrons to form stable compound; weaker than ionic
ionic bonding
one element gains an electron and one loses an electron; stronger than covalent
carbohydrates
2 hydrogen atoms to 1 oxygen atom; cell energy; example: sugar, starch, cellulose
lipids
more than 2 hydrogen to 1 oxygen; nonpolar; example: fats, oils, waxes
protiens
made of amino acids; example: seafood, milk, eggs, meat
nucleic acids
molecules of heredity; DNA & RNA
compounds
composed of 2 or more separate elements; mixture
elements
substance that cannot be broken down into a smaller substance; distinguished by atomic number
ions
atom or group of atoms where the number of electrons is not equal to the number of protons
isotopes
contain equal number of protons but different number of neutrons in nuclei; radioactive
chemical bonds
process of gaining, losing, or sharing electrons to make 2 or more atoms combine to form a stable compound
chemical reactions
any process whereby a chemical change occurs
enzyme
speed up reactions and are reused (70-90% of cells)
metabolism
all chemical changes within an organism
homeostasis
ability to maintain internal stability in an organism to compensate for environmental changes
solution
mixture of 2 or more substances
acid
high pH concentration; pH < 7
base
low pH concentration; pH > 8
pH scale
scale used to find if an element is more acidic or basic
