The standard free energy change for ATP hydrolysis is -7.3kcal/mol. The free energy change under typical cellular conditions is about -12kcal/mol. Why is there a difference?

The free energy change of each step of glycolysis is given in the table below. ∆G°’ is the free energy under standard conditions (25°C, 1M each reactant, pH 7), while ∆G is the free energy change at presumed physiological conditions. Why must no step have a positive ∆G under physiological conditions?

How can you find Kcat if you are only given Vmax, Km and [E] ? I tried using Kcat=Vmax/[E] but that didn't work. How do you know if [E] is the same as [E]total, and if it isn't how do you find it from this information: The Vmax for a particular enzyme is 10 nmols/L/s. The Km for its substrate is 5 microM. If the enzyme concentration is 10 nM, what is the kcat? a.80 nmoles/L/s b.8000 nmoles/L/s c.2 nmoles/L/s d.50 nmoles/L/s

An uncatalyzed reaction has keq=50. in the presence of an appropriate enzyme.the forward rate of the reaction increased by 20-fold.what is the equilibrium constant in the presence of the enzyme?

To carefully prepared mitochondria were added succinate, oxidized cytochrome c, ADP, orthophosphate, and sodium cyanide. The overall balanced equation is: succinate + 2 cyt c(ox) + ADP + Pi --> fumarate + 2 cyt c(red) + ATP + H2O The standard state free energy of this system is O -10.3 kJ/mol 42.5 kJ/mol O 10.3 kJ/mol -42.5 kJ/mol

Intramitochondrial ATP concentrations are about 5 mM, and phosphate concentration is about 10 mM. Consider that ADP is five times more abundant than AMP.   a. Calculate the molar concentrations of ADP and AMP at an energy charge of 0.85.   b. Calculate ∆G' for ATP hydrolysis under these conditions (∆G0' for ATP hydrolysis is -32.2 kJ/mol)       The energy charge is defined as ( [ATP] + 1/2 [ADP] ) / ( [ATP] + [ADP] + [AMP] )

The Nutrition Facts label on most food products shows % daily values based on a food energy requirement of 8,360 kJ (2,000 kcal) at normal resting state. a) Assuming that the efficiency of converting food energy to ATP is 50%, calculate the mass of ATP (in kg) that is harvested daily by the human body from 8,360 kJ of food energy. A total of 30.5 kJ of energy is needed to synthesize one mole of ATP under standard conditions. The molar mass of ATP is 505 g/mol. b) For an average 68-kg (150 lbs.) human adult, calculate the % mass of extracted ATP (from your answer in 2a) relative to body weight.

a newly identified bacterium called Nomore biochem is unable to synthesize ubiquinone. A mobile electron carrier called CXC3 is used as a substitute. From the information provided in the table, calculate delta G' and Keq value at 298K for the redox reaction that occurs in the Nomore Biochem electron transport chain. (constants: R=8.3 J/degree x mol, F= 96.1 kJ/v x mol Half Reactions E' (V) ubiquinone + 2e- + 2H+--> Ubiquinol + H2 0.045 NAD+ + 2e- + 2H+ --> NADH + H+ -0.320 CXC3 + 2e- + 2H+ --> CXC3H2 -0.450 explain the impact that using CXC3 instead of ubiquinone will have on ATP production in the cell. How might the cell adapt to this situation?

Two reactions are shown below. These reactions are directly coupled in cells by an enzyme called hexokinase, which is a key enzyme in glycolysis. It is generally the case that reactions that are directly coupled by enzymes share some common reactants. What is the net reaction when these two reactions are combined? Glucose + Inorganic Phosphate + ATP + Water → Glucose 6-phosphate + ADP Glucose + ATP + Water → Glucose 6-phosphate + ADP + Inorganic Phosphate Glucose + ATP → Glucose 6-phosphate + Inorganic Phosphate Glucose + ATP → Glucose 6-phosphate + ADP

Consider the fructose-1,6-bisphosphatase reaction. Calculate the free energy change if the ratio of the concentrations of the products to the concentrations of the reactants is 23.7, and the temperature is 37.0 °C? AG" for the reaction is -16.7 kJ/mol. The constant R = 8.3145 J/(mol-K) AG= Number kJ/mol