In maltose, glycosidic linkage is present between the two glucose units at positions

Options

A. 1,2
B. 1,1
C. 1,3
D. 1,4

Explanation

To determine the glycosidic linkage present in maltose between the two glucose units, we can follow these steps:

### Step 1: Understand the Structure of Maltose
Maltose is a disaccharide composed of two glucose units. Each glucose unit is a monosaccharide that can be represented in its cyclic form.

### Step 2: Identify the Type of Glucose
The glucose units in maltose are specifically the alpha (α) anomer of glucose. This means that the hydroxyl group (OH) on the first carbon (C1) is positioned below the plane of the ring structure.

### Step 3: Draw the Structure of Two Alpha-Glucose Molecules
When we draw two alpha-glucose molecules, we can label the carbon atoms from 1 to 6 for each glucose unit:
- For the first glucose: C1, C2, C3, C4, C5, C6
- For the second glucose: C1', C2', C3', C4', C5', C6'

### Step 4: Identify the Hydroxyl Groups
In the alpha-glucose structure, the hydroxyl groups are located at specific positions:
- C1 has an OH group (which will participate in the glycosidic bond).
- C4 also has an OH group.

### Step 5: Form the Glycosidic Linkage
When the two glucose molecules react, the hydroxyl group on C1 of one glucose reacts with the hydroxyl group on C4 of the other glucose. This reaction results in the elimination of a water molecule (H2O) and the formation of a glycosidic bond.

### Step 6: Conclude the Glycosidic Linkage Position
The glycosidic linkage in maltose occurs between the first carbon (C1) of one glucose and the fourth carbon (C4) of the other glucose. Therefore, the glycosidic linkage in maltose is a 1→4 linkage.

### Final Answer
The glycosidic linkage in maltose is present between the two glucose units at positions **1 and 4**.

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