BIOCHEMISTRY LECTURE / FIRST SEMESTER
AMINO ACIDS AND PROTEINS
LEARNING OBJECTIVES
CLASSIFICATION OF AMINO ACIDS
I. Define Amino acid and Proteins
II. Describe the structure of amino acids and the Amino acids are non-polar, polar acidic, polar basic or polar
system used to classify amino acids neutral, depending on the nature of their side chain
III. Distinguish between oligopeptides,
polypeptides and proteins and describe the 1. Non-polar - the side chain of non-polar amino is usually an
bond that joins amino acid residues in these alkyl group, an aromatic ring, or a non-polar collection of atoms.
compounds Nonpolar amino acids are glycine, alanine, valine, leucine,
IV. Define primary, secondary, tertiary and isoleucine, methionine, praline, phenylalanine and tryptophan.
quaternary structure
V. Explain what is meant by the term 2. Polar acidic - the side chain of a polar acid amino acid
denaturation, and lisyt some ways to contains a carboxyl group. At pH 7, the carboxyl group is found
denature a protein
in its conjugate base form (-CO₂), which means that the side
chains on the two polar acidic amino acids, aspartic acid and
AMINO ACIDS glutamic acid, carry a negative charge at this pH.
Amino acids are organic acids containing an amine group. 3. Polar basic - the side chain of polar basic amino acids
contains an amino group. At pH 7 the amines exist in their
The most common amino acids are α-amino acids and the
conjugate acid form. So polar basic amino acids carry a positive
most common α-amino acids are the L- α-amino acids.
charge at this pH. Polar basic amino acids are lysine, arginine,
histidine.
4. Polar neutral - the side chain of polar neutral amino acids is
usually an alcohol, a phenol. None of these functional groups is
acidic or basic enough to carry a charge at pH 7. Polar neutral
amino acids are serine, threonine, cysteine, tyrosine, asparagine
and glutamine.
It is important to understand the ff about amino acid Polarity
structure: R Group
1. Only 20L- α-amino acids are used to make proteins. Nutrition
Rare exceptions are bacterial membrane proteins which
contain a few D-amino acids. -Essential AA
2. Side chains or side groups are what distinguish the - Non-essential AA
amino acids from each other
3. Amino acids can exist as zwitterions
4. Some amino acids found in cells are not used to
make proteins
5. Amino acids are the building blocks of proteins, and
are joined by peptide bond
SOPHIA NICOLE POSERIO MACAM
UNIVERSIDAD DE MANILA
BSN- 14
, BIOCHEMISTRY LECTURE / FIRST SEMESTER
AMINO ACIDS AND PROTEINS
SOPHIA NICOLE POSERIO MACAM
UNIVERSIDAD DE MANILA
BSN- 14
AMINO ACIDS AND PROTEINS
LEARNING OBJECTIVES
CLASSIFICATION OF AMINO ACIDS
I. Define Amino acid and Proteins
II. Describe the structure of amino acids and the Amino acids are non-polar, polar acidic, polar basic or polar
system used to classify amino acids neutral, depending on the nature of their side chain
III. Distinguish between oligopeptides,
polypeptides and proteins and describe the 1. Non-polar - the side chain of non-polar amino is usually an
bond that joins amino acid residues in these alkyl group, an aromatic ring, or a non-polar collection of atoms.
compounds Nonpolar amino acids are glycine, alanine, valine, leucine,
IV. Define primary, secondary, tertiary and isoleucine, methionine, praline, phenylalanine and tryptophan.
quaternary structure
V. Explain what is meant by the term 2. Polar acidic - the side chain of a polar acid amino acid
denaturation, and lisyt some ways to contains a carboxyl group. At pH 7, the carboxyl group is found
denature a protein
in its conjugate base form (-CO₂), which means that the side
chains on the two polar acidic amino acids, aspartic acid and
AMINO ACIDS glutamic acid, carry a negative charge at this pH.
Amino acids are organic acids containing an amine group. 3. Polar basic - the side chain of polar basic amino acids
contains an amino group. At pH 7 the amines exist in their
The most common amino acids are α-amino acids and the
conjugate acid form. So polar basic amino acids carry a positive
most common α-amino acids are the L- α-amino acids.
charge at this pH. Polar basic amino acids are lysine, arginine,
histidine.
4. Polar neutral - the side chain of polar neutral amino acids is
usually an alcohol, a phenol. None of these functional groups is
acidic or basic enough to carry a charge at pH 7. Polar neutral
amino acids are serine, threonine, cysteine, tyrosine, asparagine
and glutamine.
It is important to understand the ff about amino acid Polarity
structure: R Group
1. Only 20L- α-amino acids are used to make proteins. Nutrition
Rare exceptions are bacterial membrane proteins which
contain a few D-amino acids. -Essential AA
2. Side chains or side groups are what distinguish the - Non-essential AA
amino acids from each other
3. Amino acids can exist as zwitterions
4. Some amino acids found in cells are not used to
make proteins
5. Amino acids are the building blocks of proteins, and
are joined by peptide bond
SOPHIA NICOLE POSERIO MACAM
UNIVERSIDAD DE MANILA
BSN- 14
, BIOCHEMISTRY LECTURE / FIRST SEMESTER
AMINO ACIDS AND PROTEINS
SOPHIA NICOLE POSERIO MACAM
UNIVERSIDAD DE MANILA
BSN- 14
