The most common monomer of carbohydrates is a molecule of :

Options

A. glucose E
B. maltose
C. amino acid
D. phospholipid

Explanation

To solve the question "The most common monomer of carbohydrates is a molecule of:", we will analyze the options provided and identify the correct answer step by step.

### Step 1: Understand the term "monomer"
A monomer is the basic unit or building block of a larger molecule. In the context of carbohydrates, we are looking for the simplest form of carbohydrate.

### Step 2: Analyze the options
The options given are:
1. Glucose
2. Maltose
3. Amino acid
4. Phospholipid

### Step 3: Identify the monomer of carbohydrates
- **Glucose**: This is a simple sugar and is classified as a monosaccharide, which is indeed a monomer of carbohydrates.
- **Maltose**: This is a disaccharide, which means it is composed of two glucose molecules linked together. Therefore, it is not a monomer.
- **Amino acid**: This is the monomer of proteins, not carbohydrates.
- **Phospholipid**: This is a type of lipid and not related to carbohydrates.

### Step 4: Conclusion
Since glucose is the simplest form of carbohydrate and is the most common monomer, the correct answer is **glucose**.

### Final Answer:
The most common monomer of carbohydrates is a molecule of **glucose**.

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