What does?G of a metabolic reaction measure?
the net change in free energy during a reaction
the amount of heat energy gained or lost in a reaction
the amount of matter transferred in a reaction
the change in activation energy required in a reaction due to enzyme activity
the activation energy of a reaction
Which of the following does a catalyst change during a chemical reaction?
the free energy of the products
the free energy of the reactants
ATP is not the only molecule that can drive reactions. When ATP is depleted during exercise, muscle cells use phosphocreatine to drive the regeneration of ATP.
Consider the following half reactions
1. ATP + H2O? ADP + Pi
?G = –7.3 kcal/mol
2. Phosphocreatine + H2O? creatine + Pi
?G = –10.3 kcal/mol
From these two reactions, calculate the Gibbs free energy of the following coupled reaction, catalyzed by creatine kinase
Phosphocreatine + ADP? ATP + creatine
Which is the correct net Gibbs free energy of the reaction?
?G = –3 kcal/mol
?G = –17.6 kcal/mol
?G = 0 kcal/mol
?G = +3 kcal/mol
?G = +17.6 kcal/mol
Which source of energy does active transport use?
the regeneration of ATP bound to an active transport pump
the hydrolysis of ATP bound to an active transport pump
the hydrolysis of GTP bound to the active transport pump
the transport of ATP bound to an active transport pump
the transport of GTP bound to an active transport pump
Which is an anabolic process?
The sodium-potassium pump is an active transport pump that uses energy to pump potassium into cells and sodium out of cells. Why is ATP energy required?
to change the shape of the ions
to transfer glucose in the same direction as Na+ ions
to pump the Na+ and K+ ions along their diffusion gradient
to pump the Na+ and K+ ions against their diffusion gradient
for the membrane to change shape
Which definition best describes a cell's metabolism?
the chemical reactions that break down glucose for energy
the use of ATP as an energy carrier
the energy level that must be overcome for a chemical reaction to move forward
the burning of fat molecules for energy
the sum of all the chemical reactions occurring in an organism
Which reaction can provide the energy needed to run an endergonic reaction?
All answers are correct.
Which process(es) can directly amplify signals in a transduction pathway?
activating adenylyl cyclase
activating phospholipase C
All answers are correct.
What happens when protein kinase A (PKA) phosphorylates phosphorylase kinase in the epinephrine signal transduction pathway?
Phosphorylase kinase becomes deactivated, and glucose production is suppressed.
Phosphorylase kinase becomes activated, and glucose production is suppressed.
Phosphorylase kinase becomes deactivated, and glucose production is enhanced.
Phosphorylase kinase becomes activated, and glucose production is enhanced.
None of the answers are correct.
Which is a catabolic process?
translation of mRNA into protein
Which reaction does a kinase catalyze in a signal transduction pathway?
binding of a signal molecule to a receptor
production of cAMP
phosphorylation of a target protein