Energy and Thermodynamics in Biochemistry

During catabolism, where does the chemical energy released from broken bonds primarily go?

In the context of the provided information, what is a primary difference in energy levels between the chemical bonds in propane and oxygen versus carbon dioxide and water?

How does catabolism relate to the concept of energy release and transfer in biological systems?

If a reaction involves breaking bonds in reactants that initially possess more energy compared to the bonds formed in the products, what net effect would you expect regarding energy?

Considering the energy transformation during catabolism, how does the process align with the laws of thermodynamics?

A chemical reaction results in a decrease in the system's enthalpy ($\Delta$H = -50 kJ) and an increase in entropy ($\Delta$S = +100 J/K). Which statement best describes the spontaneity of this reaction?

Consider a reaction where the products have a higher enthalpy than the reactants. What can be inferred about the reaction?

A scientist observes a reaction occurring in a closed system. Over time, the disorder within the system decreases. Based on this observation, what can be inferred about the entropy change ($\Delta$S) of the system?

During a chemical reaction, a system releases 250 J of energy into its surroundings. What effect does this energy release have on the entropy of the surroundings?

Which of the following best describes the relationship between energy, entropy, and spontaneity in a chemical reaction?

In a lab experiment, a student measures the initial enthalpy of reactants to be 35kJ and the final enthalpy of products to be 10kJ. Calculate the change in enthalpy ($\Delta$H) for this reaction.

Based on the principles of thermodynamics, how does the organization of complex molecules within a cell relate to entropy?

In a reversible reaction, what do bidirectional arrows signify?

If a reaction has a large positive $\Delta$Go’, what does this indicate about the reaction under standard conditions?

Why is ATP hydrolysis often coupled with non-spontaneous reactions in biological systems?

Consider a reaction where glucose is converted to glucose-6-phosphate with a $\Delta$Go’ of +13.8 kJ/mol. If ATP hydrolysis ($\Delta$Go’ = -30.5 kJ/mol) is coupled to this reaction, what is the overall $\Delta$Go’ for the coupled reaction?

In the context of chemical reactions, what is the significance of a unidirectional arrow?

Consider the following initial concentrations: [C] = 0.3M, [D] = 0.1M, [A] = 0.2M, and [B] = 0.3M for the reaction A + B ⇌ C + D. Calculate the reaction quotient (Q).

If the reaction quotient (Q) for a reaction is 0.5, what can be inferred about the relationship between the concentrations of reactants and products compared to the equilibrium state?

Given that ln(0.5) = -0.693, what is the practical significance of calculating the natural logarithm of a reaction quotient or equilibrium constant in biochemistry?

What condition must be met for a reaction to be considered at equilibrium?

In the reaction R-PO42– + ADP → R-OH + ATP, the ∆Go’overall is +11.1 kJ/mol and the ∆Go’ for the reaction ADP + HPO42– → H2O + ATP is +30.5 kJ/mol. What is the ∆Go’ for the reaction R-PO42– + H2O → R-OH + HPO42–?

Given the overall reaction R-PO42– + ADP → R-OH + ATP has a ∆Go’ of +11.1 kJ/mol, and the concentrations [R-PO42–] = 0.13 M, [ADP] = 0.09 M, [R-OH] = 0.002 M, and [ATP] = 0.0012 M at 37°C (310 K), calculate the actual Gibbs free energy change (∆G) for the reaction.

For a reaction with a positive standard Gibbs free energy change (∆Go’), under what conditions would the actual Gibbs free energy change (∆G) be negative, making the reaction spontaneous?

Which of the following statements accurately describes the relationship between calories, Calories, and Joules?

If a food sample raises the temperature of 500 mL of water by 20°C upon combustion, how much energy (in Calories) was released by the food sample? (Assume 1 mL of water weighs 1 gram.)

Given the following values: carbohydrate (4 Cal/g), protein (4 Cal/g), alcohol (7 Cal/g), and lipid (9 Cal/g), which of the following food combinations would provide the highest energy content (in Calories) for a 100g serving?

If a scientist determines that the combustion of a new type of fat releases 11 Calories per gram, what can be concluded about this fat compared to typical lipids?

Under non-standard conditions, a reaction has the following concentrations: [R-PO42–] = 0.2 M, [ADP] = 0.1 M, [R-OH] = 0.01 M, [ATP] = 0.005 M. If ∆Go’ is +10 kJ/mol at 298K, does the reaction favor the formation of reactants or products?

During intense exercise, the concentration of ATP decreases and the concentrations of ADP and inorganic phosphate (HPO42-) increase in muscle cells. How does this shift affect the Gibbs free energy change (∆G) for ATP hydrolysis (ATP → ADP + HPO42–)?

Catabolism

Chemical Energy

Energy Transfer

Propane vs. Oxygen

Biochemical Study

Unidirectional arrows

Bidirectional arrows

∆Go’ (Delta G naught)

Positive ∆Go’ value

Negative ∆Go’ value

ATP hydrolysis

Coupling reactions

Glycolysis step 1

Overall ∆Go’ calculation

Conservation of Energy

ΔH (Change in Enthalpy)

Spontaneous Reactions

Entropy (ΔS)

Enthalpy Units

Entropy Measurement

R-PO42– Reaction

ΔGo’R2

Overall ΔGo’

Keq

Exergonic Process

Calorie Definition

Energy Conversion

Molar Concentration

Food Energy Sources