Question

Hexokinase catalyzes the first step of glycolysis, in which glucose is phosphorylated to form glucose-6-phosphate. Which of the following statements are accurate? Choose all that apply.

Hexokinase is found in the mitochondrial membrane.

Hexokinase consists of two domains, or lobes, that come together when glucose and the MgATP2� complex are bound.

Most kinases require the presence of a monovalent metal ion cofactor to prevent ATP hydrolysis.

The conformational shift that occurs when glucose, but not water, enters the active site prevents water from hydrolyzing ATP.

Hexokinase transfers the terminal phosphate of ATP to carbon 3 of glucose.

Hexokinase is a type of transferase that catalyzes the transfer of a phosphoryl group from ATP to a hexose.

Answer 1

1.Hexokinase is found in the mitochondrial membrane.

FALSE: those are found in cytosol

2.Hexokinase consists of two domains, or lobes, that come together when glucose and the MgATP2� complex are bound.

TRUE

3.Most kinases require the presence of a monovalent metal ion cofactor to prevent ATP hydrolysis.

FALSE: Hexokinase requires Mg2+ (or another divalent metal ion such as Mn2+) for activity.

4. The conformational shift that occurs when glucose, but not water, enters the active site prevents water from hydrolyzing ATP.

TRUE:the substrate-induced conformational changes within the kinase enables it to discriminate against H2O as a substrate.

5. Hexokinase transfers the terminal phosphate of ATP to carbon 3 of glucose.

FALSE: The transfer of the phosphoryl group from ATP to the hydroxyl group on carbon 6 of glucose is catalyzed by hexokinase

6. Hexokinase is a type of transferase that catalyzes the transfer of a phosphoryl group from ATP to a hexose.

TRUE