[cs_content][cs_section parallax=”false” separator_top_type=”none” separator_top_height=”50px” separator_top_angle_point=”50″ separator_bottom_type=”none” separator_bottom_height=”50px” separator_bottom_angle_point=”50″ style=”margin: 0px;padding: 45px 0px;”][cs_row inner_container=”true” marginless_columns=”false” style=”margin: 0px auto;padding: 0px;”][cs_column fade=”false” fade_animation=”in” fade_animation_offset=”45px” fade_duration=”750″ type=”1/1″ style=”padding: 0px;”][cs_text]Forensic Chemistry > 3. Because proteins are a major structural and metabolic component of all living organisms, the analysis of protein samples can be useful in forensic chemistry > The Peptide Bond > [/cs_text][cs_text style=”color: #800000;font-family: “Oxygen”,sans-serif;”]Describe the nature of the peptide bond and explain that proteins can be broken at different lengths in the chain by choice of enzyme [/cs_text][cs_text]Nature of Peptide Bond
- Is an amide bond that connects amino acids to form polypeptide or protein
- Peptide bonds present in protein sequence can be cleaved by at different lengths in the chain via hydrolysis
- Acid and Base Hydrolysis
- Polypeptide chain is broken down into its constituent amino acids using strong acid (HCl) and base (NaOH)
- Disadvantage: Causes destruction of some amino acids
- Hydrolysis by Enzymes
- Selected peptide bond in the protein is cleaved resulting to varying length of peptide fragments
- Examples of enzymes used for cleaving proteins into peptides are:
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- Pepsin – digestive enzyme; cleaves peptide bonds involving the amino side of aromatic amino acids and acidic amino acids
- Chymotrypsin – digestive enzyme; involves in cleaving the peptide bond in the carboxyl side of aromatic amino acids
- Trypsin – digestive enzyme; involves in cleaving the peptide bond in the carboxyl side of basic amino acids
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