Chapter 9.1 Terms Flashcards Preview

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Flashcards in Chapter 9.1 Terms Deck (10):
1

Is the free energy released in the formation of a large number of weak interactions between the enzyme and the substrate.

Binding energy

2

Structural changes in both the enzyme and the substrate that facilitate catalysis, upon binding.

Induced fit

3

The active site contains a reactive group, usually a powerful nucleophile, that become temporarily covalently attached to a part of the substrate in the course of catalysis. An example would be chymotrypsin.

Covalent catalysis

4

A molecule other than water plays the role of a proton donor or acceptor. Chymotrypsin uses a histidine residue as a base catalyst to enhance the nucleophilic power of serine, whereas a histidine residue in carbonic anhydrase facilitates the removal of a hydrogen ion from a zinc-bound water molecule to generate hydroxide ion.

General acid-base catalysis

5

The reaction rate is considerably enhanced by brining the two substrates together along a single binding surface on an enzyme.

Catalysis by approximation

6

A metal ion may facilitate the formation of nucleophiles such as hydroxide ion by direct coordination. A metal ion may also serve as an electrophile, stabilizing a negative charge on a reaction intermediate.

Metal ion catalysis

7

The modification of a residue to determine reactivity and catalytic relationships. Was used to determine that serine residue plays a central role in the catalytic mechanism of chymotrypsin.

Chemical modification reaction

8

The constellation of Asp 102, His 57, and Ser 195 residues.

Catalytic triad

9

This structure stabilizes the tetrahedral intermediate of the chymotrypsin reaction.

Oxyanion hole

10

Several important drugs are _____ inhibitors. Prevents protein catabolism/ peptide hyrolysis.

Protease inhibitor