What are the functional groups present in the structure of maltose ?

Options

A. One ketal and one hemiketal
B. One acetal and one ketal
C. One acetal and one hemiacetal
D. Two acetals

Answer

To determine the functional groups present in the structure of maltose, we can follow these steps:

### Step 1: Understand the Composition of Maltose
Maltose is a disaccharide formed by the dehydration of two glucose units. Each glucose unit contains hydroxyl (–OH) groups and forms a cyclic structure.

### Step 2: Identify the Structure of Glucose
Glucose in its cyclic form has multiple hydroxyl (–OH) groups attached to its carbon atoms. Specifically, it has:
- One anomeric carbon (the carbon that is part of the hemiacetal)
- Hydroxyl groups on several other carbons.

### Step 3: Formation of Maltose
When two glucose molecules combine to form maltose, a glycosidic bond is formed between the anomeric carbon of one glucose and the fourth carbon of the other glucose. During this process, a molecule of water (H₂O) is removed (dehydration).

### Step 4: Identify Functional Groups
In maltose, we can identify the following functional groups:
1. **Hydroxyl Groups (–OH)**: Present on multiple carbons of both glucose units.
2. **Hemiacetal Group**: Formed at the anomeric carbon of one glucose molecule, where one –OH group and one ether (–O–) linkage are present.
3. **Acetal Group**: Formed at the linkage between the two glucose units, where two –O– groups are attached to the anomeric carbon.

### Step 5: Conclusion
Thus, the functional groups present in maltose include:
- Hydroxyl groups (–OH)
- Hemiacetal group
- Acetal group

### Final Answer
The functional groups present in maltose are hydroxyl groups, a hemiacetal group, and an acetal group.

---