Amino acids

Definition

Amino acids are organic compounds that serve as the building blocks of proteins, consisting of a central carbon atom, an amino group, a carboxyl group, a hydrogen atom, and a distinctive side chain or R group. These molecules play critical roles in biological processes, including protein synthesis, where they are linked together by peptide bonds to form polypeptides and ultimately proteins. Their structure is influenced by their amino and carboxylic acid functional groups, which also contribute to their properties and reactivity.

5 Must Know Facts For Your Next Test

1. There are 20 standard amino acids that combine in various sequences to create proteins, each with a specific role in biological functions.
2. Amino acids can be classified as essential or non-essential; essential amino acids must be obtained from the diet, while non-essential ones can be synthesized by the body.
3. The sequence of amino acids in a protein determines its three-dimensional structure and function, which is crucial for the protein's role in biological processes.
4. Some amino acids are also precursors for important molecules in the body, such as neurotransmitters and hormones.
5. The carboxylic acid and amino groups of amino acids allow them to act as both acids and bases, contributing to their role in buffering systems within organisms.

Review Questions

• How do the structures of amino acids influence their role in protein synthesis?
  • The structure of amino acids is crucial for protein synthesis because the unique side chains (R groups) determine how each amino acid interacts with others during peptide bond formation. This interaction influences the folding of polypeptides into specific three-dimensional shapes necessary for their functions. The presence of both an amino group and a carboxyl group allows amino acids to act as building blocks while also contributing to the overall charge and polarity of the resulting protein.
• Discuss the significance of essential versus non-essential amino acids in nutrition and metabolism.
  • Essential amino acids are those that cannot be synthesized by the body and must be obtained through diet, making them vital for maintaining health and supporting growth. Non-essential amino acids, on the other hand, can be produced by the body and are crucial for various metabolic pathways. Understanding the difference helps in dietary planning to ensure all necessary amino acids are available for protein synthesis and other physiological functions.
• Evaluate the impact of amino acid sequence on protein function and how this relates to diseases caused by mutations.
  • The specific sequence of amino acids in a protein dictates its final three-dimensional shape and functionality. Mutations that alter this sequence can lead to misfolded proteins or entirely dysfunctional ones, resulting in diseases such as sickle cell anemia. In this condition, a single amino acid substitution alters hemoglobin's structure, leading to reduced oxygen transport. This illustrates how crucial proper amino acid sequence is to maintaining health at a molecular level.

Related terms

Peptide Bonds: Covalent bonds formed between the amino group of one amino acid and the carboxyl group of another, linking amino acids together in a protein.

Proteins: Large biomolecules made up of one or more long chains of amino acids, essential for various functions within living organisms.

Side Chains: The variable groups attached to the central carbon atom in an amino acid that determine its unique properties and classification.