Enzyme Mechanisms Quiz

Enzyme Function and Composition

• The main function of enzymes is to catalyze biochemical reactions.
• There are two types of protein enzymes based on their composition: simple enzymes and complex enzymes.
• The protein part of a complex protein enzyme is called apoenzyme.

Ribozymes

• Ribozymes are distinguished from other enzymes by being composed of RNA that can catalyze chemical reactions.
• The main chemical nature of ribozymes is RNA-based.

Cofactors

• Coenzymes are mainly composed of vitamins or derived from vitamins.
• Metal ions usually compose inorganic, thermo-stable cofactors.
• Enzymes with metal prosthetic groups are called metalloenzymes.

Enzyme-Substrate Interaction

• The restricted region of an enzyme that binds to the substrate is called the active site.
• The reactant that binds to an enzyme and forms a temporary association is called substrate.
• After the formation of the enzyme-substrate complex, the substrate undergoes conversion into product.

Enzyme Classification

• The International Union of Biochemistry and Molecular Biology (IUBMB) system of enzyme nomenclature is used to classify enzymes.
• The purpose of the IUBMB system is to provide a standardized system of naming enzymes.
• The first digit in the Enzyme Commission (EC) Number denotes the enzyme class (oxidoreductases, transferases, hydrolases, lyases, isomerases, or ligases).
• The second digit in the Enzyme Commission (EC) Number denotes the enzyme subclass.

Enzyme Applications

• The analysis of the catalytic activity of enzymes allows for the diagnosis of diseases.
• Many enzymes in blood plasma play a role in the diagnosis of diseases.
• The appearance or levels of certain enzymes in blood plasma assist in the diagnosis of diseases.
• The quantitative analysis of the activity of released enzymes provides information about the extent of tissue damage.
• The EC number 2.7.1.1 indicates that hexokinase is a transferase that catalyzes the transfer of a phosphoryl group.

Other

• Transferases are a class of enzymes that catalyze the transfer of moieties such as glycosyl, methyl, or phosphoryl groups.
• The word 'enzyme' means 'in yeast' in Greek.
• The Fischer model, proposed in 1894, describes the enzyme-substrate binding process.
• Carrier proteins are a general term for proteins that assist in moving another molecule, usually across a cell membrane.