Enzymology Concepts Quiz

Enzyme Structure and Function

• The region of an enzyme surface that binds the substrate molecule and catalytically transforms it is called the active site.
• Enzymes exhibit high specificity for substrate binding, meaning they only bind to specific substrates.

Active Site Characteristics

• The surface of an enzyme's active site is lined with polar and non-polar residues that create a unique environment for substrate binding.
• The interaction between the substrate and catalytic residues creates tension, increasing the reaction rate.

Enzymatic Reactions

• Enzymatic reactions occur in specialized pockets, allowing for efficient substrate binding and catalysis.
• The main function of enzymes in chemical reactions is to lower the activation energy, allowing the reaction to proceed faster.

Modulation of Enzyme Activity

• Enzyme activity can be modulated by modifying the active site, such as through phosphorylation or binding of regulatory molecules.
• Allosteric modulators, such as small metabolites or cofactors, bind to the allosteric site of an allosteric enzyme and modify its catalytic activity.

Enzymatic Kinetics

• The transition state is a high-energy state in a chemical reaction, and enzymes help to lower the energy required to reach this state.
• The substrate must gain energy to reach the intermediate compound in a chemical reaction.
• Enzyme proximity with substrates creates a conformational change, allowing the substrate to bind more efficiently and increasing the reaction rate.

Coenzymes and Cofactors

• Vitamins B and C are mentioned as coenzymes in the text.
• Coenzymes are specialized molecules that bind to the active site of an enzyme and are essential for its activity.

Enzyme Regulation

• Enzyme catalytic activity depends on the binding of substrates and cofactors to the active site.
• The maximum rate of a reaction when the enzyme is saturated with substrate is called Vmax.
• Temperature, pH, and substrate concentration are factors that affect the reaction rate in enzymatic kinetics, but not enzyme concentration.

Metabolic Pathways

• The sequence of consecutive enzymatic reactions in which the product of one reaction becomes the substrate in the next one is called a metabolic pathway.
• The study of the rate of a reaction and how it changes in response to changes in experimental parameters is called enzymatic kinetics.

Allosteric Enzymes

• Allosteric enzymes are modulated by the noncovalent binding of a specific metabolite at a site other than the active site.
• The most common covalent modification in hormonal signal characteristic is phosphorylation.

Enzyme Components

• The part of an enzyme that is a metal ion or organic compound covalently bound to a protein and essential to its activity is called a prosthetic group.
• The part of an enzyme that consists of complex organic or metalloorganic molecules such as Coenzyme A, NADH, and FADH2 is called a cofactor.
• The specific site on the surface of an allosteric protein molecule to which the modulator or effector molecule binds is called the allosteric site.

Enzyme Activity

• The factor that represents the number of substrate molecules converted to product per unit time is called the turnover number.
• The allosteric site represents the specific site on the surface of an allosteric protein molecule to which the modulator or effector molecule binds.