Which of the following does NOT describe a mechanism that cells use to regulate enzyme activities?

A. Cells control enzyme activity by phosphorylation and dephosphorylation.

B. Cells control enzyme activity by the binding of small molecules.

C. Cells control the rates of diffusion of substrates to enzymes.

D. Cells control the rates of enzyme degradation.

E. Cells control the rates of enzyme synthesis.

F. Cells control the targeting of enzymes to specific organelles. 

#Question id: 445

#Unit 1. Structure and Function of Biomolecules

In order for a reaction to proceed spontaneously from left to right as written

#Question id: 446

#Unit 1. Structure and Function of Biomolecules

Which statement is false about ATP?

#Question id: 447

#Unit 1. Structure and Function of Biomolecules

In glycolysis, fructose 1,6-bisphosphate is converted to two products with a standard free-energy change (DG'°) of 23.8 kJ/mol.  Under what conditions encountered in a normal cell will the free-energy change (DG) be negative, enabling the reaction to proceed spontaneously to the right?

#Question id: 448

#Unit 1. Structure and Function of Biomolecules

During glycolysis, glucose 1-phosphate is converted to fructose 6-phosphate in two successive reactions: Glucose 1-phosphate -> glucose 6-phosphate DG'° = –7.1 kJ/mol Glucose 6-phosphate -> fructose 6-phosphate DG'° = +1.7 kJ/mol DG'° for the overall reaction is:

#Question id: 449

#Unit 1. Structure and Function of Biomolecules

The standard free-energy changes for the reactions below are given. Phosphocreatine -> creatine + Pi DG'° = –43.0 kJ/mol ATP ->  ADP + Pi DG'° = –30.5 kJ/mol What is the overall DG'° for the following reaction? Phosphocreatine + ADP -> creatine + ATP

#Question id: 450

#Unit 1. Structure and Function of Biomolecules

The DG'° values for the two reactions shown below are given.

Oxaloacetate + acetyl-CoA + H2O -> citrate + CoASH DG'° = –32.2 kJ/mol

Oxaloacetate + acetate    ->   citrate DG'° = –1.9 kJ/mol

What is the DG'° for the hydrolysis of acetyl-CoA?

Acetyl-CoA + H2O -> acetate + CoASH + H+