Proteins: Clinical examples and experimental evidence

Question 1

How is the importance of certain amino acid residues in catalytic capacity in enzymes shown?

Answer 1

Patients who suffer from metabolic diseases exhibit mutations that alter the primary structure of an enzyme

Question 2

Kirchhoff’s experiment

Answer 2

Converted starch into sugar by heating it with sulphuric acid. However then noticed that sulphuric acid was not consumed, showing early evidence of catalysis.

Question 3

First demonstration of enzyme specificity

Answer 3

Reaumur noted that stomach juice of buzzards would digest meat and soften bone but would leave plant material unchanged.

Question 4

Sanger experiment

Answer 4

In 1955 reported the complete amino acid sequence of insulin using X-ray diffraction, proving that proteins were chemically well defined molecules.

Question 5

Cech’s work

Answer 5

Discovered that RNA is an enzyme and can cut itself. As a control, Tetrahymena thermopila RNA was left in a test tube with no enzymes of chemicals, where it spliced itself. Then when ran on a Western Blot, the different segments could be seen.

Question 6

How are isozymes demonstrated?

Answer 6

Use gel electrophoresis and then stain after sepearation. Each isozyme shows a different pattern of bands.