Enzyme Specificity Flashcards

Study Notes

Enzyme Specificity

Enzyme specificity dictates that each enzyme catalyzes only one type of reaction.

Types of Enzyme Specificity

Three main types:
- Stereospecificity (optical specificity)
- Reaction specificity
- Substrate specificity

Stereospecificity (Optical Specificity)

Involves enzymes acting on specific stereoisomers, which have the same molecular formula but distinct structural configurations.
Enzymes like L amino acid oxidase and D amino acid oxidase target L and D amino acids, respectively.
Mechanism involves three regions on the substrate molecule complementarily binding to three enzyme regions.
Isomerases do not exhibit stereospecificity as they specialize in converting isomers.

Reaction Specificity

Refers to a scenario where the same substrate may participate in different reactions, each catalyzed by different enzymes.
Example includes amino acids that can undergo reactions like transamination, oxidative deamination, decarboxylation, and racemization, each requiring a unique enzyme.

Substrate Specificity

Varies by enzyme, categorized into three types:
- Absolute
- Relative
- Broad

Absolute Substrate Specificity

Certain enzymes exclusively interact with a single substrate.
Example: Glucokinase processes glucose to produce glucose-6-phosphate; urease converts urea into ammonia and carbon dioxide.

Relative Substrate Specificity

Some enzymes react with structurally related compounds, influenced by specific groups or bonds.
Example: Trypsin hydrolyzes peptide bonds involving arginine or lysine while chymotrypsin cleaves bonds in aromatic amino acids like phenylalanine, tyrosine, and tryptophan.

Broad Specificity

Enzymes with broad specificity can act on closely related substrates.
Example: Hexokinase works on glucose, fructose/mannose, and glucosamine, but not on galactose.

Description

Test your knowledge on enzyme specificity with these flashcards. Learn about the various types of enzyme specificity, including stereospecificty, reaction specificity, and substrate specificity. Perfect for biology students or anyone interested in biochemistry!