Principles of Biochemistry 2025/2026
Updated Test Bank-Style Study Guides with
MCQs & Answers
Monomer - answers Unit of proteins
Ampholytes (amphoteric electrolytes) - answers Can act as either a base or an acid.
--> Depends on predominant ionic species
What is the net charge of an amino acid at its isoelectric point (pI)? - answers Zero
pI= - answers pKa1 + pka2/2
--> Alanine pI= 2.34 + 9. = 6.02
Titration curve of an amino acid with a single amino and carboxyl groups is? - answers
Simple
Titration curve of an amino acid with an ionizable R-group is? - answers More complex
Amino Acid general structure - answers
zwitterionic - answers Containing a positively charged ion at one end and a negatively
charged ion at the other. Overall 0.
a-amino acids - answers Amino group attached to a-carbon
In a-amino acids, a-carbon is also a ______ ______. - answers Chiral carbon.
All amino acids have a chiral carbon except _______. - answers Glycine
Proline has a ______ structure and is another exception to the _____ _____ "rule". -
answers Cyclic; Chiral carbon
Stereoisomers - answers Isomeric molecules that have the same molecular formula and
sequence of bonded atoms (constitution), but that differ only in the three-dimensional
orientations of their atoms in space.
Geometric isomers - answers Two or more coordination compounds which contain the
same number and types of atoms, and bonds (i.e., the connectivity between atoms is
the same), but which have different spatial arrangements of the atoms
,cis and trans isomers (describe) - answers
Optical isomers - answers Molecules that differ three-dimensionally by the placement of
substituents around one or more atoms in a molecule.
How (+) and (-) enantiomers bend plane polarize light. - answers Clockwise; Counter-
clockwise
Are molecules with a chiral center optically active or inactive? - answers Active
D- - answers Dextro; Counter-clockwise
L- - answers Levo; Clockwise
R- - answers Rictus; Clockwise
S- - answers Sinister; Counter-clockwise
Only _-amino acids are found in proteins. - answers L
--> very minor exceptions
There are __ standard amino acids. - answers 20
What are the five ways the standard amino acid groups are categorized based off of
their R-groups? - answers 1. Nonploar, alipathic
2. Aromatic
3. (+) charged, basic
4. (-) charged, acidic
5. Polar, uncharged
Glycine - answers Gly
Alanine - answers Ala
Proline - answers Pro
Valine - answers Val
Leucine - answers Leu
Isoleucine - answers Ile
Methionine - answers Met
Phenyalanine - answers Phe
, Tyrosine - answers Tyr
Tryptophan - answers Trp
Serine - answers Ser
Threonine - answers Thr
Cysteine - answers Cys
Asparagine - answers Asn
Glutamine - answers Gln
Lysine - answers Lys
Histidine - answers His
Arginine - answers Arg
Aspartate - answers Asp
Glutamate - answers Glu
G - answers Glycine
A - answers Alanine
P - answers Proline
V - answers Valine
L - answers Leucine
I - answers Isoleucine
M - answers Methionine
F - answers Phenylalanine
Y - answers Tyrosine
W - answers Tryptophan
S - answers Serine