文档介绍：Resource, Materials and Environment
Lesson 2: Food Chemistry
ponents
Protein: Amino acids, Peptide and Polypetide
Carbohydrates
Fats and oils
Food Additives
Food Production
Proteins
proteins are essential parts of all anisms
Amino acids
Building blocks for protein
Properties of amino acids
Differentiation of amino acids, techniques
Chromatography and electrophoresis
Peptide bond
Dehydration synthesis (condensation) reaction forming a peptide group
Peptides are synthesized by coupling the carboxyl group or C-terminus of one amino acid to the amino group or N-terminus of another.
Peptide group
Properties of amino acids
Due to the co-existence of the NH3+and the COO-, amino acids exhibit amphoteric behaviour, for instance alanine reacts both with acids and bases;
There are twenty standard amino acids proteins by living cells. Different sequencing of amino acids results in different type of proteins.
Properties of amino acids
Amino Acid is slightly acidic. For alanine, the following reaction occurs in pure water:
Properties of amino acids
Isoelectric point
The pH at which an amino acid carries electric charge, this quantity can be determined by an analytical technique called electrophoresis
Isoelectric Point