introduction Flashcards
biochemistry
the study of chemical processes within and related to living organisms
principal types of biological molecules
carbs, lipids, proteins and nucleic acids
what is the reaction used to make biomolecules
condensation reaction (removal of water from the reacting monomers)
types of polymers
polysaccharides, disaccharides, proteins, fats, DNA and RNA
types of monomers
monosaccharides, amino acids, glycerol & fatty acids and nucleotides for DNA & RNA
polymers of amino acids monomers
proteins
what are amino acids composed of
amine portion and carboxylic acid part
composition of alpha-amino acids
an amino group, a carboxyl group, a hydrogen atom, a side chain radical (R group)
alpha carbon
the first carbon attached to the COOH group (all the groups of alpha-amino acid groups are attached to it)
the charge of the carboxyl and amino groups at physiological pH
carboxyl (negative) and amino (positive)
How do amino acids differ from each other
their side chain (radical group)
properties of amino acids (6)
- soluble in water solvents
- colorless
- stereoisomerism
- amphoteric property
- isoelectric point
- buffering activity
why are amino acids soluble in polar solvents?
due to the presence of charged groups (carboxyl and amino groups)
why are amino acids colorless?
as they don’t absorb visible light (with the exception of aromatic amino acids that absorb ultraviolet light with wave length 280nm)
what is stereoisomerism of amino acids
molecules have the same molecular formula and the same structural groups but differ in the orientation of the groups
the form of naturally occurring amino acids in mammalian proteins
L-form
the form of amino acids in bacterial cell walls and in some antibiotics
D-form
amphoteric property of amino acids
the property of amino acids to react with acid and alkali to form salts (they can act as either proton donors “alkaline media” or proton acceptors “acidic media”)
the isoelectric point of amino acids
the specific pH at which the AA will carry zero charge
(zwitterion/dipolar ion)
the buffering activity of amino acids
the acid donating or accepting protons to keep the pH of its environment constant
