Understanding Protein Domains

Amino Acids and Proteins

• Cis and trans amino acids differ in the spatial arrangement of the amino and carboxyl groups attached to the alpha carbon.
• In cis amino acids, the amino and carboxyl groups are on the same side of the alpha carbon, resulting in a bent conformation.
• In trans amino acids, the amino and carboxyl groups are on opposite sides of the alpha carbon, resulting in a linear conformation.

Chaperone Proteins

• Chaperones are proteins that assist the conformational folding or unfolding of large proteins or macromolecular protein complexes.

Globular Proteins

• Globular proteins are a type of protein that folds into a compact, rounded shape.
• Example: Hemoglobin, a globular protein found in red blood cells.
• Globular proteins have a variety of functions in the body, including acting as enzymes, hormones, immunoglobulins, and transport molecules.
• They are soluble in water or in lipid bilayers.
• Quaternary structure is held together by noncovalent forces.

Protein Domains

• Protein domains are distinct regions within a protein that can fold independently and often carry out specific functions.
• A protein domain can be thought of as a building block that can be combined with other domains to create proteins with various functions.
• Proteins often contain multiple domains, each of which can perform a different function.

Structural Motifs

• A common structural motif is the β-α-β motif, where two adjacent β parallel strands are connected by an α helix from the C-terminus of strand 1 to the N-terminus of strand.

Valence Electrons

• Valence electrons are electrons in the outer shell of an atom.
• They are essential as they determine chemical properties of the elements.

Enantiomers and Chirality

• Enantiomers are a molecule that has left and right-handed isomers.
• A chiral molecule is a molecule that has an atom bonded to four different groups.

Reactions and Bonding

• The reaction between an acid and a base is called a neutralization reaction.
• Non-metal atoms receive electrons.
• Buffer's function is to resist changes in pH.
• Intermolecular bonding is the force of attraction within the same molecule.

Atomic Number and Protein Structure

• Atomic Number is the number of protons in the nucleus, which identifies which element it is.
• Denaturation is the process of unfolding the protein.
• Lysine and Proline are identified as helix breakers.
• Motifs and domains are independent, and have structural and functional importance to protein structure.