How many chiral carbons in the linear form of D-galactose?
D-galactose has 4 chiral carbons in its linear form.
To determine the number of chiral carbons in the linear form of D-galactose, we need to understand the structure of D-galactose and identify the carbon atoms with four different substituents (chiral carbons).
D-galactose is a monosaccharide with a 6-carbon backbone. Its linear form can be represented as:
CHOH-CHOH-CHOH-CHOH-CHOH-CHO
To identify the chiral carbons, we need to assign a unique substituent to each carbon atom. In D-galactose, the substituents are assigned as follows:
C1 - Aldehyde group (CHO)
C2 - Hydroxyl group (OH)
C3 - Hydroxyl group (OH)
C4 - Hydroxyl group (OH)
C5 - Hydroxyl group (OH)
C6 - Hydroxyl group (OH)
Now, let's look at each carbon atom to see how many different substituents it has.
C1: Aldehyde group (CHO) + 3 hydroxyl groups (OH) = 4 different substituents
C2: Hydroxyl group (OH) + 3 hydroxyl groups (OH) = 4 different substituents
C3: Hydroxyl group (OH) + 3 hydroxyl groups (OH) = 4 different substituents
C4: Hydroxyl group (OH) + 3 hydroxyl groups (OH) = 4 different substituents
C5: Hydroxyl group (OH) + 3 hydroxyl groups (OH) = 4 different substituents
C6: Hydroxyl group (OH) + 1 hydroxyl group (OH) = 2 different substituents
Therefore, there are five chiral carbons in the linear form of D-galactose: C1, C2, C3, C4, and C5.