4.4: Secondary Structural Motifs and Domains - Biology LibreTexts
Beta-Alpha-Beta. The motif is a common way to connect two parallel beta strands as compared to beta hairpins, which are used to connect antiparallel beta strands. Figure \(\PageIndex{12}\) shows an interactive iCn3D model of the beta-alpha-beta structure from triose phosphate isomerase (1amk).
4.2: Secondary Structure and Loops - Biology LibreTexts
About 50% of the amino acids in a globular (spherical) protein are in regular secondary structure (alpha or beta). The amino acids in helices and beta strands are connected by stretches of amino acids which still have order, but that order is less regular than those found in helices and beta strands, which are characterized by stretches of ...
Amino acid - Wikipedia
Amino acids can be classified according to the locations of the core structural functional groups (alpha- (α-), beta- (β-), gamma- (γ-) amino acids, etc.); other categories relate to polarity, ionization, and side-chain group type (aliphatic, acyclic, aromatic, polar, etc.).
3.1: Amino Acids and Peptides - Biology LibreTexts
Jul 20, 2024 · The major building blocks of proteins are called alpha (α) amino acids. As their name implies they contain a carboxylic acid functional group and an amine functional group. The alpha designation is used to indicate that these two functional groups are separated from one another by one carbon group.
Biochemistry, Secondary Protein Structure - StatPearls - NCBI Bookshelf
Dec 11, 2022 · The alpha-helix is a right-handed helical coil held together by hydrogen bonding between every fourth amino acid. Many globular proteins have multiple alpha-helical portions separated by long stretches of non-helical regions. Some fibrous proteins, including alpha-keratin, are almost completely comprised of alpha-helices.
Sep 24, 2018 · a protein. These two forms are the beta (β)-sheet and the alpha (α)-helix, which are highly favored in protein structures because they maximize intramolecular hydrogen bonding. β-strands are discontinuous stretches of amino acids that interact with each other via hydrogen bonds to form β-sheets
Protein Structure | Learn Science at Scitable
The building blocks of proteins are amino acids, which are small organic molecules that consist of an alpha (central) carbon atom linked to an amino group, a carboxyl group, a hydrogen atom,...
Biochemistry, Amino Acid Synthesis and Degradation
Amino acids are organic compounds that consist of alpha carbon in the center, hydrogen (H), amino (-NH2), carboxyl (-COOH), and specific R (side chain) groups. One linear chain of amino acids is called a polypeptide; 1 or more polypeptides make up a protein. There are 20 major types of amino acids found in proteins, of which the differences are the side chains (R groups) that contain various ...
7.2: Amino acids - Chemistry LibreTexts
Sep 21, 2023 · Amino acids are organic compounds that contain both an amine (− NH 2) and a carboxylic acid (− COOH) group in the same molecule. For example, alanine, shown on the right, is an amino acid. Proteins contain a subclass of amino acids …
7.4: Secondary structure of proteins - Chemistry LibreTexts
Sep 21, 2023 · Define the secondary structure of proteins and understand the structural features of major secondary structures, including \(\alpha\)-helix, \(\beta\)-pleated sheet, random coil, and triple helix structures.