which of the following is basic amino acid

Options

A. glycine
B. valine
C. alanine
D. arginine

Answer

To determine which of the following is a basic amino acid, we can follow these steps:

### Step 1: Understand the Classification of Amino Acids
Amino acids can be classified into three categories based on the nature of their side chains:
- **Basic amino acids**: These have side chains that can accept protons (H+) and typically contain additional amino groups (-NH2).
- **Acidic amino acids**: These have side chains that can donate protons and usually contain carboxyl groups (-COOH).
- **Neutral amino acids**: These do not have significant acidic or basic properties.

### Step 2: Identify the Basic Amino Acids
Common basic amino acids include:
- **Lysine (Lys)**: Contains an additional amino group in its side chain.
- **Arginine (Arg)**: Contains a guanidinium group which is positively charged at physiological pH.
- **Histidine (His)**: Has an imidazole side chain that can be protonated.

### Step 3: Analyze the Given Options
Assuming the options provided include various amino acids, we need to identify which of them fall into the category of basic amino acids.

### Step 4: Select the Correct Answer
From the analysis, we can conclude that:
- **Arginine** is a basic amino acid due to its side chain structure.
- **Lysine** is also a basic amino acid.
- Other amino acids like glycine, alanine, and others may be neutral or acidic.

Thus, if the options include arginine, it is the correct answer as a basic amino acid.

### Final Answer
The basic amino acid among the options provided is **Arginine**.

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