An allosteric (meaning "other site") inhibition will involve binding of a molecule to a site other than the active site. Competitive inhibition involves the binding of an inhibitor molecule to the active site of an enzyme. Both forms of inhibition decrease the rate of an enzyme-catalyzed reaction.

Molecules that are able to bind to an enzyme and prevent it from reaching  are noncompetitive inhibitors. Take carbon monoxide for example. The molecule binds to the hemoglobin but stays attached to it. Oxygen is not able to break the covalent bond between the carbon monoxide and the heme group and is therefore a noncompetitive. With carbon monoxide permanently attached to the heme, the hemoglobin cannot reach full saturation of oxygen and therefore  is lowered.

Allosteric sites on an enzyme bind both enhancers and inhibitors. Since the question only states that it binds to allosteric site, the molecule could be an inhibitor or an enhancer of the enzyme. Recall that inhibitors inhibit the activity of the enzyme whereas enhancers increase the activity of the enzyme.

Noncompetitive inhibitors and/or activators bind to the allosteric site. Competitive inhibitors, on the other hand, bind to the active site; therefore, this molecule cannot be a competitive inhibitor. Competitive inhibitors decrease the affinity between enzyme and substrate whereas noncompetitive inhibitors do not alter the affinity. Since we already determined it cannot be a competitive inhibitor, this molecule cannot decrease the affinity.

Noncompetitive inhibition is characterized by a decrease in the maximum velocity (or efficacy) of an enzyme. Noncompetitive inhibitors bind irreversibly to the enzyme and prevent the substrate-enzyme activity. This decreases the efficacy of the enzyme. Unlike competitive inhibition, noncompetitive inhibition cannot be overcome by increasing the concentration of substrates because of the irreversible interaction between inhibitor and enzyme.

Noncompetitive inhibition does not alter the Michaelis-Menten constant, . This means that the affinity between enzyme and substrate is not altered in noncompetitive inhibition. Noncompetitive inhibitors bind to allosteric sites on the enzyme and prevent the substrate-enzyme interaction by altering the active site. Sometimes, noncompetitive inhibitors allow for substrate-enzyme interaction but inactivate the activity of the enzyme; therefore, noncompetitive inhibitors allow for substrate binding sometimes, but they always prevent the enzyme activity and the enzymatic reaction.

The question states that the bond between nitrogen and hydrogen atoms occur between adjacent molecules; therefore, this is an intermolecular bond. Recall that hydrogen bonds are intermolecular bonds that occur between hydrogen atoms and either nitrogen, oxygen, or fluorine atoms. This means that the intermolecular bond involved in this question is a hydrogen bond. Hydrogen bonds (like other intermolecular bonds) are reversible and can be broken by applying some energy. Since the bond between the inhibitor and the enzyme is reversible, the inhibitor must be a competitive inhibitor. Noncompetitive inhibitors, on the other hand, bind irreversibly (via covalent bonds) to the allosteric site on the enzyme.

Competitive inhibitors can be overcome by increasing substrate concentration. This occurs because the reversible, weak bonds between the inhibitor and enzyme can be broken when there is excess substrate present (substrate competes with the competitive inhibitors for the enzyme). Competitive inhibitors also increase the Michaelis-Menton constant, . Increasing  decreases affinity between substrate and enzyme.

Non-competitive inhibitors work by binding the enzyme without hindering the substrate's access to the active site. Therefore, the affinity of the enzyme to its substrate is not impacted , however it does negatively impact the enzyme's ability to form the final product. Therefore, the maximum velocity  of the reaction is decreased. 

Uncompetitive inhibition occurs when an inhibitor binds to an allosteric site of a enzyme, but only when the substrate is already bound to the active site. In other words, an uncompetitive inhibitor can only bind to the enzyme-substrate complex.

Uncompetitive inhibition occurs when an inhibitor binds to an allosteric site on the enzyme, but only when it is an enzyme-substrate complex. Because the inhibitor binds to the enzyme-substrate complex and then changes the enzyme's conformation, it makes it incredibly difficult for the substrate to become unbound from the enzyme. Thus, the apparent affinity of the substrate for the enzyme is dramatically increased. A decrease in  represents an increase in affinity.  still decreases when an uncompetitive inhibitor binds.

With uncompetitive inhibitors, the inhibitor binds to a site separate from the binding site of the substrate. This can occur even while the substrate is bound to the enzyme, blocking the process and reduce the catalysis of the enzyme. 

This will result in the reduction of Vmax because the enzymes ability for catalysis is being reduced by the binding of inhibitor to the enzyme-substrate complex. Km does not change because the substrate and the uncompetitive inhibitor bind to different sites. 

The correct answer is that uncompetitive inhibitors of enzymes only affect enzymes that act on multiple substrates. Uncompetitive inhibitors bind to the enzyme-substrate complex only, not to the free enzyme. They distort the active site to prevent the enzyme from being catalytically active without actually blocking the binding of the substrate. This cannot occur with an enzyme that only acts on a single substrate at a time. Adding more substrate and lowering the amount of free enzyme available both apply to competitive inhibitors, which bind to free enzymes and block the substrate-binding site of the enzyme. Uncompetitive inhibitors do decrease the apparent K_M on a Lineweaver-Burke plot, but they also lower the apparent V_M.