what are the 4 levels of protein folding?
607170
The different levels of protein structure are known as primary, secondary, tertiary, and quaternary structure.
1391866
['Structural proteins: e.g. the collagen, the fibrillins, and elastin.', 'Specialized proteins: e.g. fibronectin, the various laminins, and the various integrins.']
1270908
The two most common secondary structural elements are alpha helices and beta sheets, though beta turns and omega loops occur as well. Secondary structure elements typically spontaneously form as an intermediate before the protein folds into its three dimensional tertiary structure.
1099922
Each of these repeats corresponds to a discrete, compactly folded region of protein structure known as a protein domain. The light chain is made up of two such immunoglobulin domains, whereas the heavy chain of the IgG antibody contains four (see Fig. 3.1a).
122799
There are four major classes of biological macromolecules (carbohydrates, lipids, proteins, and nucleic acids), and each is an important component of the cell and performs a wide array of functions.
1055675
['Initiation: The ribosome assembles around the target mRNA. ... ', 'Elongation: The tRNA transfers an amino acid to the tRNA corresponding to the next codon. ... ', 'Termination: When a peptidyl tRNA encounters a stop codon, then the ribosome folds the polypeptide into its final structure.']
1341186
Tertiary structure results from the interactions between the side chains (R groups) of the various amino acids. ... Disulfide Bridges form where two amino acids containing sulfhydryl groups on their side chains are brought close together by how the protein is folding.
1045794
['Dissolve in water (rather than oils / fats)', 'Are formed from amino acids - which are themselves the structural units of proteins and are soluble in water.', 'Cannot pass through the target cell membranes (which include fatty components).']
1443052
Albumin comprises three homologous domains that assemble to form a heart-shaped protein. Each domain is a product of two subdomains that possess common structural motifs.
295988
['Proteases: Break down protein into small peptides and amino acids.', 'Lipases: Break down fat into three fatty acids plus a glycerol molecule.', 'Amylases: Break down carbs like starch into simple sugars.']
791326
['Initiation. ... ', 'Elongation. ... ', 'Termination. ... ', 'Post-translation processing of the protein.']
1026517
The function of a protein is directly dependent on its threedimensional structure (Figure 3.1). Remarkably, proteins spontaneously fold up into three-dimensional structures that are determined by the sequence of amino acids in the protein polymer.
206068
"Myoglobin has a tertiary structure as it is a protein monomer. Only multi-subunit protein complexes, like hemoglobin have quaternary structure. ... Myoglobin has a 3-D structure, as it is a single protein molecule, so it has a tertiary structure."
380476
There are 20 amino acids that make up proteins and all have the same basic structure, differing only in the R-group or side chain they have. The simplest, and smallest, amino acid is glycine for which the R-group is a hydrogen (H).
464337
['Primary Structure. The specific sequence of amino acids making up a polypeptide chain.', 'Secondary Structure. The regular local patterns of coils or folds of a polypeptide chain.', 'Tertiary Structure. ... ', 'Quaternary Structure.']
855863
Secondary Structure. The secondary structure of a protein refers to stable local folding of portions of the protein involving hydrogen bonding between backbone atoms. The two most common secondary structures are the alpha helix and the beta pleated sheet.
1408287
Compared to RNA and DNA backbone, protein backbone has a relatively simple chemical structure - a nitrogen atom, two carbon atoms, one or two oxygen atoms, and a few hydrogens.