Question

The two functional groups characteristic of sugars are:

• A. Carbonyl and methyl
• B. Carbonyl and phosphate
• C. Carbonyl and hydroxyl
• D. Hydroxyl and methyl

Answer 1

The correct option is C

Carbonyl and hydroxyl

The correct option is C.

Explanation for the correct option:

1. The soluble carbohydrates include sugars.
2. The main chemical components of sugars are carbon, hydrogen, and oxygen.
3. Carbohydrates are polyhydroxy aldehydes, ketone, or their derivatives, which indicates they have a carbonyl and hydroxyl group.
4. A carbonyl group is made up of a double bond connecting an oxygen atom and a carbon atom i.e,$\mathrm{C}=\mathrm{O}$.
5. A hydroxyl group is a functional group with the chemical formula $-\mathrm{OH}$ consisting of one oxygen atom covalently bound to one hydrogen atom.
6. Usually, carbohydrates decompose within the body to release energy.
7. Monosaccharides, oligosaccharides, and polysaccharides are the three types of carbohydrates.
8. Polysaccharides are large carbohydrates or biomacromolecules.

Explanation for the incorrect option:

Option (A):

1. An acyl group is a wider family of moieties that includes acetyl groups.
2. Two components combine to form an acyl group.
3. There is the carbonyl group first.
4. Alkyl groups, which consist entirely of a molecule of carbon and hydrogen, are a second component.
5. A single bond between a methyl group and a carbonyl exists in the acetyl group.
6. Acetyl groups are found in substances like acetic acid and the neurotransmitter acetylcholine.
7. Hence, it is an incorrect option

Option (B):

1. A phosphate group joined to an acyl group is what is known as an acyl phosphate.
2. They are high-energy derivatives of carboxylic acids.
3. Acyl phosphates play a key role in many life-sustaining chemical processes occurring inside living cells, making them essential components of biological systems.
4. Hence, it is an incorrect option

Option (D):

1. An hydroxyl and methyl group is found in amino acids i.e. Serine
2. It is crucial for producing the phospholipids that make up the cell membrane and maintain the cell's structural integrity.
3. Hence, it is an incorrect option

Final answer: The two functional groups characteristic of sugars are carbonyl and hydroxyl.