Study Guide B pt 2 Flashcards
What is a polar molecule?
a molecule with a slightly positively charged region and a slightly negatively charged region
Explain why water is a polar molecule.
the oxygen nucleus pulls the electrons in the molecule more strongly than the hydrogen atoms. The hydrogen atoms have a slight positive charge and the oxygen atom has a slight negative charge.
What is a hydrogen bond?
an attraction between a slightly positive hydrogen and a slightly negative atom
Describe where a hydrogen bond can form among water molecules.
between the slightly positive hydrogen atom of one water molecule and the slightly negative oxygen atom of another water molecule.
describe high specific heat
a large amount of energy is needed to produce an increase in water temperature; water resists changes in temperature
describe cohesion
water molecules “stick” to each other
describe adhesion
water molecules “stick” to other substances
What is the difference between a solvent and a solute?
a solvent is present in greater concentration and dissolves the solute
What types of substances dissolve easily in water?
polar molecules and ions
What types of substances do not dissolve easily in water?
Nonpolar molecules (such as fats & oils)
Effect an acid has on H+ concentration in a solution
increases H+ concentration
Effect a base has on H+ concentration in a solution
decreases H+ concentration
Effect an acid has on pH
lower pH
Effect a base has on pH
raise pH
define solution
a homogeneous mixture of substanes
define solvent
substance present in greater amount in which other substances dissolve
define solute
substance that dissolves in a solvent
Why is carbon often called the building block of life?
carbon atoms are the basis of the molecules that make up most living things
What ability allows carbon atoms to form a large number of molecules?
carbon atoms can form covalent bonds with up to four other atoms, including other carbon atoms
function of carbohydrates
broken down as a source of chemical energy (short term energy); part of cell structure
function of lipids
broken down as a source of chemical energy (long term energy); part of cell structure
function of proteins
many functions, including movement, transport, chemical catalysts
function of nucleic acids
store genetic information, build proteins
examples of carbohydrates
sugars, starches, cellulose
examples of lipids
fats, oils, phospholipids
examples of proteins
enzymes, hemoglobin