Because  for the reaction is negative, it is spontaneous and proceeds favorably to the right. Equilibrium does not occur when the concentrations of reactants and products are equal; it occurs when the rates of forward and reverse reactions are equal. At equilibrium  thus there is no net change in the concentration of either the reactants or the products.

If two complementary single strands of DNA are put into a solution, they will spontaneously form dsDNA.  This process results in a loss of heat from the system - demonstrating that it is an enthalpically favorable process.  However, it is entropically unfavorable given the formation of a more ordered structure.

Insulin is produced by pancreatic beta cells in response to a rise in blood sugar, which occurs after eating a meal rich in carbohydrates (sugars and starches). It causes other cells of the body to take up the blood sugar (primarily glucose) and use it for energy production, and it prompts the liver to store excess glucose as glycogen. Glucagon is produced when blood sugar is too low, and it blocks glycolysis and prompts liver cells to convert stored glycogen back to glucose and release it and also produce glucose through gluconeogenesis. This is always determined by the ratio of the levels of two hormones - if there is far more insulin than glucagon, its physiological effects will dominate. There is never absolutely zero of either hormone unless the individual is diabetic to such a degree that their cells cannot produce insulin. 

A negative change in Gibbs free energy means that a reaction will take place spontaneously. By using the equation:

We can see that if both entropy and enthalpy are positive,  will only be negative when  is sufficiently high.

Reaction coupling is the pairing of one unfavorable reaction to another reaction that is favorable. The energetics of the favorable reaction drive the unfavorable one forward.

It is a common misconception that at chemical equilibrium, movement between the product and reactant sides of the equation has stopped. In reality, reactants and products are still converting back and forth to one another, however there is no longer any net movement from one side of the equation to the other. Also, Q=Keq at equilibrium.

All of the answer choices given in this question are true statements, and they are all reasons why endergonic reactions can occur within living things.

Oftentimes, reactions that require a large input of energy are thermodynamically coupled to the hydrolysis of ATP, the energy currency of the cell. As a result, ATP is able to provide the fuel, so to speak, for powering the reaction.

Also, it's important to note that standard free energy changes are much different than the free energy changes that occur under physiological conditions. Standard state assumes that all reactants and all products of a reaction start out at a concentration of , but this concentration is absurdly high for just about any compound found within cells.

Lastly, the products of some endergonic reactions are often used up quite readily. As a result of this, the concentration of product is kept at a low level, which means that the reactions becomes favored toward making more product.

A nucleoside triphosphate - as its name suggests - is a DNA base with three phosphate groups. During polymerization, these base groups will be continuously connected to each other in order to form a DNA strand. This is thermodynamically favorable because during the polymerization, two of the three phosphate groups on the nucleoside triphosphate will detach as a pyrophosphate. This will then be hydrolyzed which is extremely thermodynamically favorable. And so, the polymerization itself is considered to be thermodynamically favorable.

The R (relaxed) state hemoglobin is triggered by hemoglobin binding to oxygen. The heme group in R state hemoglobin is perfectly planar. By nature, R state hemoglobin is stabilized in the presence of oxygen, not in the absence of oxygen. 

To answer this question, it's important to know how the standard free energy change of a reaction is related to other various parameters of the reaction.

The standard free energy change of a reaction can be presented in different expressions.

For the purposes of this question, the bottom expression is the one we need. If we set the change in standard enthalpy term equal to zero, we can solve for our answer.