Catabolic Metabolism - Proteins, Proteolysis, and Amino Acids Properties

Question 1

Recognize the basic structure of an amino acid.

Answer 1

COOH-CH(NH2)-R

Question 2

Classify each amino acid according to its unique functional group.

Answer 2

Acidic - DE - Glutamic Acid, Aspartic Acid
Basic - HRK - Histidine, Arginine, Lysine
Sulfer Containing - Cysteine, Methionine

Question 3

Describe the dependency of amino acid structure on pH and the buffering properties of amino acids.

Answer 3

COO- and NH3+ make the amino acid neutral at pH 7. This acts as a buffer.

Question 4

Show how a mutation which results in an amino acid change would increase or decrease a protein’s isoelectric point, water solubility and/or function.

Answer 4

If the amino gains a + or loses a -, then the pKa needs to increase to account for the change and vice versa

Question 5

Compare and contrast the terms genomics and proteomics.

Answer 5

Genomics - the study of an organisms complete genes

Proteomics - the study of an organisms complete collection of proteins

Question 6

Define the types of chromatography used to purify proteins from analysis.

Answer 6

Gel Filtration - size exclusion, the smaller the protein, the more time is spends in the porous gel. Larger proteins come out first
Cation Exchange - proteins buffered at low pH. The stationary phase is negatively charged to capture positively charged proteins. High pH solution that run through the system to remove desired proteins
Anion Exchange - opposite of cation exchange
Affinity - Ligand-covered beads to capture proteins with specificity for antigen, substrate, etc.