24.3 Amino Acids and Polymers Quiz

Study Notes

Amino Acids Overview

Amino acids are essential nitrogen-containing molecules in living organisms.
The 20 common amino acids are crucial for various biological processes.

Structure of Amino Acids

Comprised of a central carbon atom bonded to a carboxyl group, an amino group, a hydrogen atom, and a unique R-group side chain.

Properties of Amino Acids

Differences in amino acid properties arise from varied R-group side chains.
Side chains can be nonpolar (aliphatic/aromatic), polar, acidic, or basic.

Peptide Bonds

Peptide bonds form between the carboxyl group of one amino acid and the amino group of another.
Each bond results from a condensation reaction, generating a water molecule.

Writing Peptide Formulas

Peptide formulas are conventionally written with the free amino group on the left and the free carboxyl group on the right.

Amino Acid Sequence

The sequence of amino acids in a peptide is expressed using three-letter abbreviations (e.g., Asp—Glu—Gly).
Peptides can be extended indefinitely through condensation polymerization.

Polypeptides and Proteins

A peptide chain with over ten amino acids is termed a polypeptide.
Chains exceeding 100 amino acids are classified as proteins, which are vital biomolecules found in skin, hair, nails, and muscles.

Sources of Amino Acids

Some amino acids are synthesized by the body, while others must be obtained from protein-rich foods such as beans and brown rice.

Protein Structure

The 3D structure of proteins is influenced by interactions among amino acids within the peptide chains.
Hydrogen bonds between folded chains contribute to maintaining protein shape.

Helix Structure

Some peptide chains coil into a regular spiral known as a helix, as observed in myoglobin, which stores oxygen in muscle tissue.

Pleated Sheet Structure

Peptide chains can also form a pleated sheet configuration by arranging side by side.

Enzymes as Catalysts

Enzymes, a subset of proteins, serve as biological catalysts, speeding up chemical reactions by lowering activation energy without being consumed in the process.

Fun Fact

Urease was the first enzyme isolated (by James B. Sumner in 1926) and is involved in breaking down urea, a component of urine.

Description

Test your knowledge on amino acids and their importance in biochemistry with this quiz. Explore the structure and functions of amino acids, which are crucial for life. Perfect for students studying biochemistry and molecular biology.