Electrochemistry

Determine Structure of Undigested Protein

← Back to Amino Acids & Proteins

Digestion of proteins can be carried out using 2 methods:

Acid-Base Hydrolysis	Enzyme Cleavage
Non-selective Overlapping fragments	Selective No overlapping fragments Require 2 sets of data from different enzymes to elucidate structure

Approach

Acid-Base Hydrolysis	Enzyme Cleavage
Spot repetition of residues in fragments	Determine terminal residues; common in 2 sets of data Spot repetition between the sets of data

Example (Hydrolysis):

Partial hydrolysis of a polypeptide produced the following fragments:

asp – lys – gly

val – phe – asp

lys – val – phe

gly – phe – lys

Determine the structure of the undigested polypeptide.

Spot repetition of residues in fragments

Structure: val – phe – asp – lys – gly – phe – lys – val – phe

Example (Enzyme):

A polypeptide was digested with 2 different enzymes. For each enzyme, the following fragments were obtained.

Enzyme 1

Enzyme 2

asp – lys – gly – phe

lys – val – arg

val – phe

gly – phe – lys

val – arg

val – phe – asp – lys

Determine the structure of the undigested polypeptide.

Step 1: Determine terminal residues; common in 2 sets of data

→ left terminal: val – phe

Step 2: Spot repetition between the sets of data

Green: From Enzyme 2, we can determine:

val – phe is followed asp – lys

Blue: From Enzyme 1, we can determine:

val – phe – asp – lys is followed by gly – phe

Yellow: From Enzyme 2, we can determine:

val – phe – asp – lys – gly – phe is followed by lys

Purple: From Enzyme 1, we can determine:

val – phe – asp – lys – gly – phe – lys is followed by val – phe

Structure: val – phe – asp – lys – gly – phe – lys – val – phe

- Chemical Bonding
NOTES: TYPES OF QUESTIONS: Determine Structure and Bonding Draw Dot-Cross Diagrams Determine Type of Bonding for Simple Molecules Predict/ Account for Physical Properties ...

- Determine Structure & Bonding
← Back to Chemical Bonding Determine Structure: Structure Metals Giant Ionic Lattice Ionic Compounds Giant Ionic Lattice Covalent Compounds Giant/ Simple Molecule Structure Metal and Non-Metals...

- Distinguishing
← Back to Organic Chemistry Problem-Solving Approach Approach: Spot the difference: FG or structure? FG: Use a test specific to the FG present in only one of the two compounds. Structure: Most of the time → Iodoform or selective oxidation...

- Ionic Equilibria (acid/ Base)
There are two broad aspects of this chapter: Acid/ Base Equilibria Solubility Equilibria Acid/ Base Equilibria Important Relations p = -log10 At 25°C: pH + pOH = pKw = 14 pKa + pKb = 14 [H+][OH–] = 10-14 Ka x Kb = Kw = 10-14 Approach:...

- H2 Chemistry Syllabus (2008)
PHYSICAL CHEMISTRY 1. ATOMS, MOLECULES AND STOICHIOMETRY • Relative masses of atoms and molecules • The mole, the Avogadro constant • The calculation of empirical and molecular formulae • Reacting masses and volumes (of solutions and gases) 2....

Electrochemistry