2. Water
Water has a high heat capacity, and a
high heat of vaporization. It is called the
universal solvent because of its general
solvent properties.
Water forms hydration layers, which are
layers of water molecules that insulate
large charged molecules.
3. Hydrolysis reactions are decomposition
reactions whereby water is added to each
bond to be broken
A dehydration synthesis reaction involves
the removal of a water molecule for every
bond formed.
4. Salts
A salt is an ionic compound containing
cations other than H+ and anions other
than the OH-.
Electrolytes are substances that conduct
an electrical current in solution.
5. Acids and bases
Acids are proton donors, that dissociate
to release hydrogen ions and anions.
Bases are proton acceptors, that
dissociate to produce hydroxides and
cations.
HCO3- and NH3 are important bases in the
human body.
6. pH is a measure of hydrogen ion
concentration of a solution (in moles per
liter). A pH of 7 is neutral; a higher pH is
alkaline, and a lower pH is acidic.
Normal blood pH is 7.35-7.45.
7. HCl + NaOH -> NaCl + H2O is an
example of a neutralization reaction.
Buffers help to prevent excessive
changes in the pH of body fluids.
8. Acids that dissociate completely are
known as strong acids, whereas acids that
do not dissociate completely are known
as weak acids.
9. Strong bases dissociate easily in water
and quickly tie up H+ whereas weak bases
ionizes incompletely and reversibly.
H2CO3 -> HCO3- + H+ is an example of a
buffer system.
11. Carbohydrates
Carbohydrates are biomolecules that
contain carbon, hydrogen and oxygen in
the ratio CH2O.
Monosaccharides are simple sugars
containing from three to seven carbon
atoms.
12. Galactose and fructose are isomers of
glucose, which means they have the same
molecular formula by their atoms are
arranged differently.
13. A disaccharide is formed when two
monosaccharides are joined by
dehydration synthesis.
Disaccharides must be broken down by
hydrolysis into monosaccharides to be
absorbed by the body.
14. Polysaccharides are long chains of simple
sugars linked together by dehydration
synthesis, to create polymers.
15. Lipids
Lipids are organic compounds that are
insoluble in water but dissolve readily in
other lipids and in organic solvents.
Neutral fats, composed of fatty acid
chains and glycerol, are found chiefly in
fatty tissue; they serve as insulation and
reserve body fuel.
16. Neutral fats are called triglycerides
because of the 3:1 fatty acid to glycerol
ratio.
Saturated fatty acid chains have only
single covalent bonds between carbon
atoms.
17. Fatty acids that contain one or more
double bonds between carbon atoms are
unsaturated.
18. Phospholipids are modified triglycerides
with a phosphorus-containing group and
two fatty acid chains.
Steroids are flat molecules made of four
interlocking hydrocarbon rings, the most
important of which is cholesterol.
19. Eicosanoids are derived from a 20-carbon
fatty acid, most important of which are
the prostaglandins.
20. Proteins
Proteins are the basic structural material
of the body, although some play
functional roles.
The building blocks of proteins are
molecules called amino acids, which are
composed of an amine, and a carboxylic
acid.
21. Peptide bonds join amino acid monomers
together by dehydration synthesis to form
proteins.
22. Most proteins are macromolecules, which
contain 100 to 10,000 amino acids.
The most common type of secondary
protein structure is the alpha helix which
resembles a slinky.
23. The beta pleated sheet is another type of
secondary structure, but instead of coiling it
has a ribbon-like structure.
24. Fibrous proteins are extended and strand-
like, most exhibit secondary structure,
and are insoluble in water.
Fibrous proteins are also known as
structural proteins, because they are the
chief building blocks of the body.
25. Globular proteins are spherical structures
with tertiary or quaternary structure, also
known as functional proteins.
26. When the hydrogen bonds of proteins
break due to environmental stresses, the
protein becomes denatured.
When functional protein become
denatured, they lose their active sites and
can no longer perform their physiological
roles.
27. Enzymes are globular proteins that act as
biological catalysts.
A holoenzyme is composed of a protein
portion called an apoenzyme, and a non
protein portion called a cofactor.
Organic cofactors are derived from
vitamins, and are called coenzymes.
28. Enzymes lower the activation energy
necessary for a reaction to proceed.
A substrate is the substance upon which
the enzyme acts.
29. Nucleic acids (DNA and RNA)
Nucleic acids are composed of carbon,
oxygen, hydrogen, nitrogen, and
phosphorus, and are the largest molecules
in the body.
Nucleotides are the structural units of
nucleic acids, and consist of five
varieties of nitrogenous bases: adenine,
guanine, cytosine, and thymine.
30. Two major classes of nucleic acids are
deoxyribonucleic acid (DNA), and
ribonucleic acid (RNA).
DNA is a long, double-stranded polymer
coiled into a shape that resembles a spiral
staircase, called a double helix.
31. The bases that bond to each other are
called complementary bases, and always
bond to the same partner.
32. Adenosine triphosphate
Energy released during the breakdown of
glucose is captured and stored in the high
energy phosphate bonds of adenosine
triphosphate (ATP).
