Identify each of the following as D or L:

The structure is

We have to find the isomer.

In this problem, we have to identify given structures as D or L.

The difference between $L$and $D$isomers is in the position of the -$OH$group in the penultimate carbon atom. The $OH\hspace{0.17em}$group in the $D$isomer of the penultimate carbon is on the right side, and in $L$isomer is on the left side. In the Figure below, we can see examples of $D$and $L$isomers on glyceraldehyde.

In this example, the penultimate carbon has the hydroxy group on the left side, which means that this structure is the $L$isomer.

The structure is

We have to find the isomer.

In this problem, we have to identify given structures as $D$or $L$.

The difference between $L$and $D$isomers is in the position of the $OH$group in the penultimate carbon atom. The $OH$in the $L$isomer of the penultimate carbon is on the right side, and in $D$isomer is on the left side. In the Figure below, we can see examples of $D$and $L$isomers on glyceraldehyde.

b) In this example, the penultimate carbon has the hydroxy group on the left side, which means that this structure is the $L$isomer.

The structure is

We have to find the isomer

In this problem, we have to identify given structures as $D$or $L$.

The difference between $L$and $D$isomers is in the position of the $OH$group in the penultimate carbon atom. The $OH$in the $D$isomer of the penultimate carbon is on the right side, and in $L$isomer is on the left side. In the Figure below, we can see examples of $D$and $L$isomers on glyceraldehyde.

In this example, the penultimate carbon has the hydroxy group on the right side, which means that this structure is the D isomer.