Question 1

A hydrogen bond can form between a hydrogen atom on a(n)

Accepted Answer

A hydrogen bond can form between a hydrogen atom on an electronegative donor group (such as oxygen or nitrogen) and another electronegative atom (such as oxygen or nitrogen). This type of bond is a result of the partial positive charge on the hydrogen atom and the partial negative charge on the electronegative atom, creating an electrostatic attraction.

Question 2

The __________ system controls the interconversion among ATP, ADP, and AMP.

Accepted Answer

The adenylate system refers specifically to the interconversion between ATP, ADP, and AMP. The other choices are not specific enough or are too broad to describe this process.

Question 3

Organisms on Earth cannot easily exist at temperatures below 0 $\degree$C because at that temperature

Accepted Answer

At temperatures below 0°C, water molecules begin to freeze and form ice crystals. This can cause damage to the cells and tissues of organisms, leading to their inability to survive in such low temperatures.

Question 4

Given the energy charge equation below, if a biological system has an EC = 0.8, what is true about the concentrations of ATP, ADP, and AMP in the system?

Accepted Answer

The energy charge equation is EC = ([ATP] + 0.5[ADP])/([ATP] + [ADP] + [AMP]). If the EC = 0.8, then ([ATP] + 0.5[ADP])/([ATP] + [ADP] + [AMP]) = 0.8. Rearranging this equation gives 0.2[ATP] = 0.3[ADP] + 0.5[AMP]. Since the concentrations of ATP, ADP, and AMP must add up to 1, we can substitute 1 - [ATP] for [ADP] + [AMP], giving 0.2[ATP] = 0.3(1 - [ATP]) + 0.5(1 - [ATP]). Simplifying this equation gives [ATP] = 0.67, [ADP] = 0.24, and [AMP] = 0.09. Therefore, there is more ATP in the system than ADP or AMP.

Question 5

The standard free energy change is defined under what set of conditions?

Accepted Answer

The standard free energy change (ΔG°) is defined under standard conditions of 1 atmosphere (1 atm) pressure, 298 Kelvin (298 K) temperature, and 1 molar (1 M) concentration. This is the most commonly used set of conditions for calculating and comparing standard free energy changes of different reactions.

Question 6

What chemical reaction causes ATP to be a high-energy molecule?

Accepted Answer

The answer of What chemical reaction causes ATP to be...

Question 7

Under steady-state conditions in a mammalian cell, the adenine nucleotide concentrations are [ATP] = 3.3 mM, [ADP] = 1.2 mM, and [AMP] = 0.2 mM. What is the energy charge of this cell?

Accepted Answer

The energy charge of a cell is calculated using the formula: $[ATP] + 0.5[ADP] / ([ATP] + [ADP] + [AMP])$. Plugging in the given values: $3.3 + 0.5(1.2) / (3.3 + 1.2 + 0.2) = 0.83$.

Question 8

If a reaction has a $\Delta$ H $\lt$ 0 and $\Delta$ S $\lt$ 0, under which conditions would the reaction be spontaneous in the forward direction?

Accepted Answer

When both ΔH and ΔS are negative, a reaction is spontaneous at low temperatures. This is because the negative ΔH (exothermic reaction) becomes more significant at lower temperatures, making the Gibbs free energy (ΔG = ΔH - TΔS) negative, which indicates spontaneity.

Question 9

In a hydrogen bond between a water molecule and another water molecule,

Accepted Answer

In a hydrogen bond between water molecules, the partial positive charge on the hydrogen atom of one water molecule is attracted to the partial negative charge on the oxygen atom of another water molecule. This forms a weak electrostatic interaction known as a hydrogen bond, with the hydrogen atom and oxygen atom of different water molecules being the parts involved in the bond.

Question 10

If $\Delta$G= 0 for a reaction, then this reaction

Accepted Answer

The given equation F1F1F1S1F1F1F10G F1F1F1S1F1F1F10 0 indicates that the Gibbs free energy change, ΔG, is zero which means the system is at equilibrium. Thus, there is no driving force for the reaction to proceed in either direction.

Question 11

If the Gibbs free energy change value for a reaction is less than zero, this reaction is

Accepted Answer

A negative Gibbs free energy change indicates that the reaction is exergonic, meaning it releases energy.

Question 12

For a given reaction with a $\Delta$ G   $\lt$ 0, the reaction is

Accepted Answer

The negative value of delta G indicates that the reaction is spontaneous and favorable in the forward direction. However, it does not provide information about the reverse direction.

Question 13

If the equilibrium constant (K_eq) is greater than 1, which direction will the reaction proceed?

Accepted Answer

If the equilibrium constant is greater than 1, it means that the ratio of products to reactants is higher than the ratio of reactants to products. Therefore, the reaction will spontaneously move towards the products to achieve equilibrium.

Question 14

If the equilibrium constant (K_eq) is greater than 1, what is the value of $\Delta$G $\degree$?

Accepted Answer

When the equilibrium constant (K_eq) is greater than 1, it indicates that the reaction favors the formation of products at equilibrium. This means the Gibbs free energy change (ΔG°) for the reaction is negative, indicating a spontaneous process under standard conditions.

Question 15

If a reaction has a $\Delta$H $\gt$ 0 and a $\Delta$S $\lt$ 0, then __________ and the reaction is at all temperatures.

Accepted Answer

The answer of If a reaction has a $\Delta$H $\gt$...

Question 16

Hydrogen bonds in liquid water are formed between

Accepted Answer

Hydrogen bonds in liquid water are formed between the oxygen of one molecule and the hydrogen of another. This is due to the partial positive charge of the hydrogen atom and the partial negative charge of the oxygen atom created by the unequal sharing of electrons in the covalent bond between them. This creates an attraction between neighboring water molecules, forming hydrogen bonds.

Question 17

Describe how an antifreeze protein functions.

Accepted Answer

Antifreeze proteins function by having regularly spaced threonine residues that bind to ice crystals, preventing them from growing larger. This mechanism allows organisms that produce these proteins to survive in subzero temperatures.

Question 18

Under what conditions could a biological reaction spontaneously proceed to reactants if the $\Delta$G$\degree$ $\gt$ 0?

Accepted Answer

The symbol "" indicates a reaction that is not spontaneous, and the symbol "" indicates standard conditions. The standard free energy change (G) for this reaction is positive (since it is proceeding in the non-spontaneous direction). Therefore, under standard conditions, the reaction will proceed from reactants to products. However, if product concentrations become greater than reactant concentrations (as is the case in answer choice B), then the reaction can become spontaneous in the reverse direction. Therefore, the correct answer is B.

Question 19

The interaction between an amino group and a carboxylate group is best characterized as

Accepted Answer

The interaction between an amino group and a carboxylate group is an ionic interaction, as the amino group has a positive charge and the carboxylate group has a negative charge, allowing them to attract each other electrostatically. This interaction plays a crucial role in the formation and stabilization of peptide bonds in proteins.

Question 20

The transfer of a phosphate from ATP to another molecule produces a(n)

Accepted Answer

When a phosphate group is transferred from ATP to another molecule, the recipient molecule becomes a highly reactive intermediate, as it has gained energy from the transfer. This energy can be used to drive chemical reactions or perform work in a cell.

Quiz 2: Physical Biochemistry: Energy Conversion, Water, and Membranes

A hydrogen bond can form between a hydrogen atom on a(n)

The __________ system controls the interconversion among ATP, ADP, and AMP.

Organisms on Earth cannot easily exist at temperatures below 0 $\degree$ C because at that temperature

Given the energy charge equation below, if a biological system has an EC = 0.8, what is true about the concentrations of ATP, ADP, and AMP in the system?

The standard free energy change is defined under what set of conditions?

What chemical reaction causes ATP to be a high-energy molecule?

Under steady-state conditions in a mammalian cell, the adenine nucleotide concentrations are [ATP] = 3.3 mM, [ADP] = 1.2 mM, and [AMP] = 0.2 mM. What is the energy charge of this cell?

If a reaction has a $\Delta$ H $\lt$ 0 and $\Delta$ S $\lt$ 0, under which conditions would the reaction be spontaneous in the forward direction?

In a hydrogen bond between a water molecule and another water molecule,

If $\Delta$ G= 0 for a reaction, then this reaction

If the Gibbs free energy change value for a reaction is less than zero, this reaction is

For a given reaction with a $\Delta$ G $\lt$ 0, the reaction is

If the equilibrium constant (K_eq) is greater than 1, which direction will the reaction proceed?

If the equilibrium constant (K_eq) is greater than 1, what is the value of $\Delta$ G $\degree$ ?

If a reaction has a $\Delta$ H $\gt$ 0 and a $\Delta$ S $\lt$ 0, then __________ and the reaction is at all temperatures.

Hydrogen bonds in liquid water are formed between

Describe how an antifreeze protein functions.

Under what conditions could a biological reaction spontaneously proceed to reactants if the $\Delta$ G $\degree$ $\gt$ 0?

The interaction between an amino group and a carboxylate group is best characterized as

The transfer of a phosphate from ATP to another molecule produces a(n)

Quiz 2: Physical Biochemistry: Energy Conversion, Water, and Membranes

A hydrogen bond can form between a hydrogen atom on a(n)

The __________ system controls the interconversion among ATP, ADP, and AMP.

Organisms on Earth cannot easily exist at temperatures below 0 °\degree° C because at that temperature

Given the energy charge equation below, if a biological system has an EC = 0.8, what is true about the concentrations of ATP, ADP, and AMP in the system?

The standard free energy change is defined under what set of conditions?

What chemical reaction causes ATP to be a high-energy molecule?

Under steady-state conditions in a mammalian cell, the adenine nucleotide concentrations are [ATP] = 3.3 mM, [ADP] = 1.2 mM, and [AMP] = 0.2 mM. What is the energy charge of this cell?

If a reaction has a Δ\DeltaΔ H <\lt< 0 and Δ\DeltaΔ S <\lt< 0, under which conditions would the reaction be spontaneous in the forward direction?

In a hydrogen bond between a water molecule and another water molecule,

If Δ\DeltaΔ G= 0 for a reaction, then this reaction

If the Gibbs free energy change value for a reaction is less than zero, this reaction is

For a given reaction with a Δ\DeltaΔ G <\lt< 0, the reaction is

If the equilibrium constant (Keq) is greater than 1, which direction will the reaction proceed?

If the equilibrium constant (Keq) is greater than 1, what is the value of Δ\DeltaΔ G °\degree° ?

If a reaction has a Δ\DeltaΔ H >\gt> 0 and a Δ\DeltaΔ S <\lt< 0, then __________ and the reaction is at all temperatures.

Hydrogen bonds in liquid water are formed between

Describe how an antifreeze protein functions.

Under what conditions could a biological reaction spontaneously proceed to reactants if the Δ\DeltaΔ G °\degree° >\gt> 0?

The interaction between an amino group and a carboxylate group is best characterized as

The transfer of a phosphate from ATP to another molecule produces a(n)

Organisms on Earth cannot easily exist at temperatures below 0 $\degree$ C because at that temperature

If a reaction has a $\Delta$ H $\lt$ 0 and $\Delta$ S $\lt$ 0, under which conditions would the reaction be spontaneous in the forward direction?

If $\Delta$ G= 0 for a reaction, then this reaction

For a given reaction with a $\Delta$ G $\lt$ 0, the reaction is

If the equilibrium constant (K_eq) is greater than 1, which direction will the reaction proceed?

If the equilibrium constant (K_eq) is greater than 1, what is the value of $\Delta$ G $\degree$ ?

If a reaction has a $\Delta$ H $\gt$ 0 and a $\Delta$ S $\lt$ 0, then __________ and the reaction is at all temperatures.

Under what conditions could a biological reaction spontaneously proceed to reactants if the $\Delta$ G $\degree$ $\gt$ 0?