NR 503 Midterm Exam Questions and Answers (2026) | Exam Prep Material | Verified Questions & Answers | A+

NR 503 Midterm Exam Questions and
Answers (2026) | Exam Prep Material |
Verified Questions & Answers | A+
• Amino acid. CORRECT ANSWER: Building blocks of proteins.
Amino group + Carboxylic acid + R group = Amino acid


Nitrogen with at least
one Hydrogen attached
Can be NH2 or NH3+


Carbon that sits
between amino
and carboxyl.
Hydrogen "hat"


Carbon with two
attached oxygens
Can be COOH or COO-


• Amino Acid Structure. CORRECT ANSWER: Consist of a Backbone
side chain/R group
Carboxyl group: Carbon with two attached oxygens
Can be COOH or COO-

, Amino Group: Nitrogen with at least one Hydrogen attached Can be
NH2 or NH3+
Alfa Carbon (a carbon): Carbon that sits between amino
and carboxyl Hydrogen "hat"


Side chain/R group: consists of...
Varible group: Unique portion of the
amino acid.


• Amino Acid types. CORRECT ANSWER: Are identified by the R
(variable)group.
Hydrophobic: no charge, no S, N, or O
Polar: no charge, must contain a S,N, or O
Charged: Have a Charge


• Ionic Bonds (Charged amino acids). CORRECT ANSWER: Two
charged amino acids form a iconc bond.
Bond disrupted by: pH or Salt concentration


Charged amino acids form ionic bonds with other
oppositely charged amino acids.
Other charges like H+ from pH or salts (charged
particles) break up these bonds.