The sequence in which amino acids are linked to one another in a protein molecule is called its:

Options

A. Primary structure
B. Secondary Structure
C. tertiray structure
D. all of these

Answer

To answer the question regarding the sequence in which amino acids are linked to one another in a protein molecule, we can break down the explanation into clear steps:

### Step-by-Step Solution:

1. **Understanding Amino Acids**:
- Amino acids are the building blocks of proteins. Each amino acid has a specific structure that includes an amino group (NH2), a carboxyl group (COOH), a hydrogen atom (H), and a variable side chain (R group).

2. **Linking Amino Acids**:
- Amino acids are linked together through a specific type of bond called a peptide bond. This bond forms between the carboxyl group of one amino acid and the amino group of another.

3. **Peptide Bond Formation**:
- The formation of a peptide bond occurs through a condensation reaction, where a water molecule (H2O) is removed. This reaction involves the OH group from the carboxyl group of one amino acid and an H atom from the amino group of another amino acid.

4. **Primary Structure Definition**:
- The sequence in which amino acids are linked together in a protein is referred to as the primary structure of that protein. This structure is linear, meaning that it does not have any folding or bending.

5. **Characteristics of Primary Structure**:
- The primary structure is crucial because it determines the protein's overall shape and function. The specific order of amino acids dictates how the protein will fold into its secondary and tertiary structures.

### Final Answer:
The sequence in which amino acids are linked to one another in a protein molecule is called its **primary structure**.

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