Each turn of the citric acid cycle is powered by one molecule of acetyl-CoA, resulting in three and one . The net reaction is:

Since twelve are produced, there must have been an input of four acetyl-CoA molecules and four total turns in the cycle. As a result, four molecules were produced.

Tertiary alcohols react most rapidly via SN1 mechanisms because they form stable tertiary carbocations. Primary and secondary alcohols typically react most rapidly via SN2 mechanisms.

Of the available options, is the only one that contains a tertiary alcohol.

Reaction 1 represents an SN2 reaction. The rate limiting step involves both reactants coming together to form a transition state. The rate of this reaction depends on the concentration of both the organic molecule and the nucleophile.

In contrast, reaction 2 is an E1 reaction, in which the rate limiting step is the removal of the leaving group to form a carbocation. In E1 and SN1 reactions, adjusting the concentration of the halide only is enough to affect the rate.

A chiral center is defined as a tetrahedral atom with four unique substituents. In the molecule above there exists only one carbon that has four different substituents, which is carbon #4 (counting from the right). Carbon #4 has -chloro and -hydroxy groups, as well as two different longer alkyl chains. No other atom has four unique substituents.

Reaction 1 represents an SN2 reaction. The rate limiting step involves both reactants coming together to form a transition state. The rate of this reaction depends on the concentration of both the organic molecule and the nucleophile.

In contrast, reaction 2 is an E1 reaction, in which the rate limiting step is the removal of the leaving group to form a carbocation. In E1 and SN1 reactions, adjusting the concentration of the halide only is enough to affect the rate.

A secondary amine is an amine (nitrogen atom) that is attached to two carbon-containing groups (alkyl groups or aryl groups). The nitrogen in ephedrine is attached to two alkyl groups, making it a secondary amine.

Primary amines are generally written as . Secondary amines are generally written as . A tertiary amine will be bound to three different R-groups. Quaternary amines require a positive charge on the nitrogen atom to accommodate a fourth R-group.

The Hofmann product is the most favored product in a Hofmann elimination reaction. The reaction follows an E2 mechanism, where a quaternary ammonium salt is able to be removed from a hydrocarbon, resulting in an alkene product. This reaction results in the least substituted alkene being the primary product.

An enantiomer is defined as a stereoisomer that is a mirror image of another. In other words, if a molecule was placed in front of a mirror, its mirror image would be the enantiomer. Questions such as these require a bit of visualization, but should be easy points. In addition, if you see the answer choice quickly and are confident in your decision, move onto the next question without spending time on the other choices, as mental geometry and visualization may take more time than anticipated.

Cells need a constant supply of NAD+ to accept electrons during glycolysis in order to produce pyruvate from glucose.

A secondary amine is an amine (nitrogen atom) that is attached to two carbon-containing groups (alkyl groups or aryl groups). The nitrogen in ephedrine is attached to two alkyl groups, making it a secondary amine.

Primary amines are generally written as . Secondary amines are generally written as . A tertiary amine will be bound to three different R-groups. Quaternary amines require a positive charge on the nitrogen atom to accommodate a fourth R-group.