Question

Draw the correct Lewis structure for the amino acid glycine?

Answer 1

The Lewis structure for the amino acid glycine consists of a central carbon atom bonded to an amino group (NH₂), a carboxyl group (COOH), a hydrogen atom (H), and a variable side chain (R).

Step-by-step explanation:

Glycine is the simplest amino acid, and its Lewis structure reflects its molecular composition. The central carbon (C) atom forms four bonds: one with the amino group (NH₂), one with the carboxyl group (COOH), one with a hydrogen atom (H), and one with the variable side chain (R). The amino group has two hydrogen atoms bonded to the nitrogen atom, and the carboxyl group includes a double bond with one oxygen atom and a single bond with another oxygen atom, which also has a hydrogen atom bonded to it. This arrangement adheres to the octet rule, ensuring that each atom, except hydrogen, has a full outer shell of electrons.

Understanding the Lewis structure of glycine is crucial for comprehending its chemical properties and reactivity. The arrangement of atoms and the distribution of electrons provide insights into how glycine interacts with other molecules, particularly in the context of protein formation where amino acids serve as building blocks. The amino and carboxyl groups are essential functional groups in amino acids, participating in peptide bond formation during protein synthesis.

In summary, the Lewis structure of glycine showcases its fundamental molecular architecture, highlighting the connectivity and electron sharing among its constituent atoms. This structural representation serves as a foundation for understanding the chemical behavior and biological significance of glycine in the context of proteins and cellular functions.

Answer 2

The Lewis structure of glycine, H₂NCH₂CO₂H, involves attaching the amine group (-NH₂) and the carboxyl group (-CO₂H) to two central carbon atoms and completing the octets for each atom. The geometry around each atom varies from tetrahedral to trigonal planar and bent. Glycine can form different ions in acidic or basic solutions, relevant when considering its behavior in water.

Step-by-step explanation:

The correct Lewis structure for the amino acid glycine, which has the molecular formula H₂NCH₂CO₂H, can be drawn by following these steps:

Place the two carbon atoms in the center with a single bond connecting them.

Attach the amine group (-NH₂) to the left carbon and the carboxyl group (-CO₂H) to the right carbon.

Add two hydrogens to the left carbon (amine-linked carbon) and complete the octets for all atoms except hydrogen, which follows the duet rule.

Ensure there are no charges by checking that each atom has the proper number of bonds (hydrogen forms one bond, oxygen forms two, nitrogen forms three, and carbon forms four).

The local geometry can be predicted by considering the number of bonding electron pairs around each atom; nitrogen has three bonds and one lone pair resulting in a tetrahedral geometry, the central carbon is also tetrahedral, the carbon in the carboxyl group has a trigonal planar geometry, and the oxygen with hydrogen attached in the carboxyl group also has bent geometry due to the two lone pairs on oxygen.

When glycine is dissolved in 1 M HCl, it will form a positively charged cation due to the protonation of the amine group, while in 1 M KOH, glycine will form a negatively charged anion due to the deprotonation of the carboxyl group.

To draw the Lewis structure of glycine in water, consider the acid-base character of the amino acid and the fact that it can zwitterion with a protonated amine group and deprotonated carboxyl group.