Proteins are polymers of _. hydrocarbons amino acids CH2O units glycerol nucleotides
The correct answer and explanation is:
Correct Answer: Amino acids
Explanation (300 words):
Proteins are polymers of amino acids, which are organic molecules that serve as the building blocks of all proteins. A polymer is a large molecule made up of repeating units, and in the case of proteins, these units are amino acids.
Each amino acid has a central carbon atom (called the alpha carbon) bonded to four groups:
- A hydrogen atom (H)
- An amino group (–NH₂)
- A carboxyl group (–COOH)
- A unique side chain or R group, which determines the identity and properties of the amino acid
There are 20 standard amino acids used by cells to build proteins. These amino acids are linked together by peptide bonds, which form through a dehydration synthesis (condensation) reaction between the amino group of one amino acid and the carboxyl group of another. This forms a dipeptide, and continued linkage creates a polypeptide chain.
Once formed, the polypeptide chain folds into a specific three-dimensional shape, which is essential for the protein’s function. The sequence and number of amino acids determine the protein’s structure and role in the body.
Proteins perform a vast array of functions, including:
- Enzymatic activity (e.g., amylase breaking down starch)
- Structural support (e.g., collagen in connective tissues)
- Transport (e.g., hemoglobin carrying oxygen)
- Defense (e.g., antibodies)
- Cell signaling and more
The other options are incorrect:
- Hydrocarbons are simple organic molecules made of carbon and hydrogen, not building blocks of proteins.
- CH₂O units are the basic formula for carbohydrates, not proteins.
- Glycerol is a component of lipids.
- Nucleotides are the building blocks of nucleic acids like DNA and RNA.
Therefore, amino acids are the correct answer as they are the monomers that make up proteins.